The Life Sciences in Eighteenth-Century French Thought 9780804780834, 0804780838

Table of contents :
Frontmatter
Preface to the 1993 Edition (page xv)
Preface to the Second Edition (1971) (page xxxix)
Preface to the Original Edition (1963) (page xli)
PART I The End of the Renaissance, 1660-1670
ONE / The Medical and Scientific Spirit of the First Half of the Seventeenth Century (page 3)
TWO / The Battle with Shadows (page 37)
THREE / In Search of Clear Ideas (page 74)
Conclusion to Part I (page 124)
PART II The Scientists' Philosophy, 1670-1745
FOUR / The New Scientific Mentality (page 133)
FIVE / New Discoveries in Animal Reproduction (page 205)
SIX / The Preexistence of Germs (page 259)
SEVEN / Problems with Preexistence (page 308)
Conclusion to Part II (page 354)
PART III The Philosophers' Science, 1745-1770
EIGHT / Precursors and Mavericks (page 369)
NINE / Buffon (page 426)
TEN / Resistance to the New Science (page 475)
Conclusion to Part III (page 530)
Epilogue (page 543)
Notes (page 561)
Bibliography (page 691)
Supplementary Bibliography (page 733)
Index (page 735)

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The Life Sciences in Eighteenth-Century French Thought

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for they were accessible to human reason. In the fine points of the facts, these general laws came down to mechanisms, similar in their nature to those

that the human mind could imagine and that the hand of man could construct. From this grandiose and daring ensemble, the science of the first half of the eighteenth century retained only one certainty—namely, that nature was a gigantic machine whose works we could take apart. Most often, one even had to give up the idea of relating these known works to one another. As for raising our investigation to the level of attempting to understand how the machine had been constructed, it was out of the question. Only He who had created it could say. Nearly all the scientists of the day were to call upon this Clockmaker God, this Supreme Artisan. And after finding shelter in the shade of His perfect wisdom, they would most often judge it useless to go any further. This is what we must now examine.

The New Scientific Mentality 181

IV The God of Philosophers and Scientists

Traditional science, in the first half of the seventeenth century, had more to say about nature than about God. It was accepted, of course, that God was the first cause of all things, even teratisms. But He remained a very distant first cause. Between God and phenomena was interposed the activity of nature, an as yet ill-defined activity and rather obscurely conceived, but nonetheless considered great enough to stray at times from God's intentions. None of these ideas was spelled out very clearly, but they could at least free the scientist from formal reflection on the attributes of the divinity. The general current of the new ideas changed all that. Nature ceased being an active power; it no longer consisted of anything except a purely passive matter, shaped in different ways and subject to the general and binding rules of motion. Descartes and a few others had already said as much before 1650, and Boyle had considered it useful to repeat the lesson.*?’ By the same token, nature found itself discharged of all the responsibilities that traditional science had assigned it, which were transferred to God, not as creator of matter, but as regulator of the laws of motion, or, better yet, as unmediated Creator of the universe. In any case, God was coming close to becoming the central character in all scientific reflection.

Descartes had dodged the difficulty. Having created matter, God had ceased to interfere in Creation except to maintain its existence. It was therefore perfectly useless for scientists to concern themselves with God, and their only enquiry should be into the laws of motion. Science did not need to go back all the way to God. Conversely, theological considerations could teach the scientist nothing, for God’s designs were impenetrable. The search for final causes thus had no place in science; it was even excluded from metaphysics, because God’s intentions were inaccessible to us.**8 This attitude of Descartes’s was roundly criticized even before 1670, especially by Boyle, who was doubly influenced by his ardent Christian faith *°? and by the tradition of chemical philosophy.*® Descartes’s view of Creation was more mechanistic than Christian. Boyle’s was more Christian than mechanical: he never managed to “believe that either these Cartesian laws of motion, or the Epicurean casual concourse of atoms, could bring matter into so orderly and well contrived a fabrick as this world.” 3°! “I think, then, that the wise Author of nature did not only put matter into motion, but, when he resolved

182 THE SCIENTISTS PHILOSOPHY to make the world, did so regulate and guide the motions of the small parts of the universal matter,” Boyle wrote.?*? In other words, it was only when “the world being once framed, and the course of nature established” that mechanical processes started functioning.*°? This attitude reveals a lesser degree of confidence in the resources of mechanism, and we shall return to it,>%4 but it also comes closer to the Christian idea of Creation. For Boyle, the importance of this consideration appears far more clearly in connection with final causes. Descartes’s position assumes a notion of the divinity very far removed from the one animating the Judaeo-Christian tradition. The God of Abraham, Isaac, and Jacob is definitely a transcendent God, but His transcendence did not keep Him from revealing Himself to His people or from enlightening them concerning at least a part of His designs. In order to believe that the Sun had been created to provide man with light, Descartes had said, it would be necessary for God to have revealed this to us.*°* Well, Boyle

answered, “a Christian philosopher has the right to think that the sun was made, among other reasons, to light up the earth and for man’s use, since Scripture teaches us that not only the sun and the moon, but also the stars of the firmament, which Descartes probably considered as so many suns, had been made to provide light to the earth.” Whereupon he refers us to Deuteronomy 4:9!36° Descartes was thus to be classed among those who professed Christianity but repeated the errors of pagan philosophers ignorant of God, or who had imagined Him as entirely different from the God of the Jews and the Christians.3°” This did not mean that all of God’s designs were accessible to us, but that some of them had to be, that God had most likely arranged the world in such a way that man could discover in it the traces of His wisdom,**®

and that consequently it was an offense towards God and a lack of trust in Him “to banish consideration of final causes from natural philosophy.” *° It must be clearly understood that final causes as Boyle conceived of them

| had nothing in common with Aristotle’s final causes. They were not in nature, and if they acted upon nature, it was through the mediation of the divine will, which had set up physical and efficient causes in such a way as to fulfill its designs. The final causes explained nothing and the scientist, in his specifically scientific activity, must not allow them to intrude. But as a Christian he was obliged to recognize their existence and to see in them proof of

God’s wisdom. And this was going to change his attitude as an investigator, despite himself. For the scientist would always be tempted to seek from Christian explanations what science withheld from him. Theoretically, the distinction was clear. In practice, unfortunate ambiguities might arise. Thus,

The New Scientific Mentality 183

noting that the pupils of oxen were slit horizontally while those of cats were slit vertically, Boyle commented: “The reason may be that horses and oxen, accustomed to finding their food growing from the soil, can more properly receive the images of the grass stretching around them, etc., because their pupils are placed transversally; whereas cats, living principally off of rats and mice, animals that ordinarily climb up or come down along walls and other steep places, the most convenient placement for their pupils was vertical, in order for them to discover these creatures quickly and track them.” *”° What resurfaced here was the idea that animals had been perfectly adapted by the Creator to the type of life that they were to lead; but above all we should note the alarming indeterminacy of Boyle’s formulation, “The reason may be...” For minds less alert to the requirements of science than Boyle’s, this was an open door for all the teleological fancies of Galen. And the danger was all the greater in that Galenic teleology, far from being dead, was intimately bound up with the medical tradition, and thus found in modern science an unexpected ally: when the Journal des Savants gravely informed its readers in 1684

that in Ethiopia, according to Father Dos Santos, women were so fertile that | they could not nurse all their children, but that “Providence makes up for the lack by giving men breasts as abundant in milk as those of their wives,” could a skeptical spirit not expect to have Boyle and his cats thrown in his face? For after all, it was hard to see why God would be more attentive to the feeding of cats than of Ethiopians.*”! From 1670 on, Boyle’s attitude was adopted more and more broadly in the scientific community. Although the two questions are intimately related, the various ways of conceiving Creation (to which we shall have the opportunity to return) will not be explored here.*”? Let me simply say that for reasons that were at the same time religious and intellectual, the immense majority of scientists considered God to have created the visible world without mediation. In this universe direct from the hands of God, the search for final causes could not be pointless. At the end of the seventeenth century, there was thus scarcely anyone willing to restrict scientists from considering final causes, aside from a few men of doubtful orthodoxy. An exception needs to be made for faithful Cartesians such as the abbé Claude Nicaise and Johann

Waldschmidt.?”* The best known among the “unorthodox” was the Epicurean Guillaume Lamy, whose Discours anatomiques created scandal in 1675

with its anti-teleology and attracted refutations inspired by the most orthodox Galenism.?” It is not surprising, however, to see Claude Brunet, whose mind-set I have already described, assert that “the final cause is beyond con-

184 THE SCIENTISTS PHILOSOPHY sideration in nature, where everything possessing the capacity to come into existence never fails to appear, whatever ill may come of it.”?”? For thinkers of this sort, Descartes served merely as guide to, or screen for, Epicurus, if not yet for Spinoza, whom Lamy and Brunet do not seem to have known. This was what Leibniz strongly emphasized to the abbé Nicaise: from Descartes’s stance “it follows that there is neither choice nor providence; what doesn’t happen is impossible, and what happens is necessary. Exactly as Hobbes and Spinoza say more explicitly.” °”° Perrault was thus highly suspicious of “those

among the philosophers who maintain with such affectation that we see not at all into the works of God,” for they “must have other motives than the respect that they feign for the impenetrable depth of eternal Wisdom.” *”” In this way, a certain category of scientists who placed Descartes in the service of Epicurus, while officially leaving God the “honor of having created matter and having launched it out in vortices,” came to be defined. But whoever had “a fairly good nose” would understand that it sufficed to declare matter eternal and motion essential to matter in order to get rid of God.?”* Voltaire would have good grounds for saying, in the wake of many others, that Descartes led to atheism.°”?

Official science, however, kept clear of these paths. The impiety of Lamy or Brunet was as foreign to it as the raciness of their language. The anatomists and naturalists were for the most part as convinced Christians as Boyle and as little disposed as he to divide their thought into two compartments, faith and science. The piety of Claude Perrault is well known, as well as the convert’s enthusiasm displayed by Steno **° and the faith of Winslow (a Bossuet convert),**' of Duverney the elder, who feared his excessive attachment to anatomy would lead to the loss of his soul, of Méry, for whom anatomy © sang the glory of God, of Swammerdam, who nearly sank into obscure mysticism under the aegis of Antoinette Bourignon,** and, finally, of Jan Godaert,

who saw in the metamorphoses of insects an image of the resurrection of the body.?8* The Christian philosophers who participated in scientific work or who were content simply to follow its progress— Bossuet, Malebranche, Leibniz—found it easy to integrate modern science with religious thought. In England, this union between scientists and theologians was still closer, as we shall see. In Paris, the science of the Académie was a Christian science, and one was soon to see the astonishing spectacle of Fontenelle awarding — with God only knows what sort of hidden smile—carefully measured certificates of piety to deceased academicians, while recalling endlessly that physics

The New Scientific Mentality 185

led to God. Still, whether sincere or merely conformist, the scientists’ Christianity necessarily led them to find proofs of divine wisdom in the universe. For Perrault as for Boyle, “the admirable Worker of the miracles seen in the structure of animal organs did not wish to hide from us entirely the wisdom he had deployed.” 384 It was therefore not “too presumptuous to aver that God set the eyes near the top of the head in the intention that we see things from afar”; there was no “rashness in judging that God placed teeth in the mouth in order to crush the fruits of the earth and make them more fitting for nourishment of the body.” **? The God of the Christians, closer to His creation than the God of Descartes, did not scorn to give a glimpse of his intentions for man’s edification.

In any case, God’s wisdom as seen in His works displayed no sign of a capricious or changing will. The God of the Christians was also a mechanistic God. The small number, the simplicity, and the uniformity of the principles

He had established were among the marks of His grandeur, according to Boyle.3*° The general applicability of these laws, which pursued ends superior

to the specific good of each individual, explained certain regrettable phenomena, such as earthquakes, floods, and famines.**” For, as noted, God was directly responsible for His creation, and it was hence urgent to explain why all was not perfect in the universe. Leibniz and Malebranche adopted analogous positions: God acted in a “simple, uniform, and constant” manner, and His will, subject to the “eternal and necessary” law of order, was in some sense the foundation of the rationality of the world.**? Duverney, too, believed that God acted “within the world in a constant and uniform fashion through the general law of the transmission of motion.” °°? Thus, we had to admire God in the regularity of nature, even when this regularity was responsible for the transmission of inherited illnesses.°?® Refusing God’s wisdom a role was tantamount to abandoning everything to the whims of chance, and if there was some rashness in guessing at God’s designs in the physical organization of man, it was certainly “a highly ridiculous rashness to claim that chance has arranged in a certain way the parts of the human body.” *”’ To base things on chance meant simultaneously denying what was evident and destroying the rationality of the world, which alone allowed us to build a science. Mechanism thus was easily able to accommodate itself to the search for final causes. One might even say that mechanism required this search, or at least en-

couraged it. “In order to explain a machine, the best procedure would be to reveal what it is intended to do, and then to show how all its parts serve

16 THE SCIENTISTS PHILOSOPHY this intention.” *°* Therefore, “if God is the Author of things, and if He is sovereignly wise, it is not possible to reason effectively on the structure of the universe without bringing in the intentions of His wisdom.” 7”? The search for final causes was, then, an integral part of science, especially in the life sciences: “The animal’s body is at the same time a hydraulic, pneumatic, and pyrobolic machine, whose end it is to maintain a certain movement; and by showing what favors this end and what impedes it, it would be possible to explain all of physiology as well as therapeutics. Thus, it is clear that final causes are useful in nature study [Physzque], not only in generating admiration for God’s wisdom, which is the principal matter, but also for helping us know and control things.” 3°* This was exactly how the anatomists conceived of their teaching, they who never failed to show how the structure and placement of an organ corresponded to its use. But they knew, too, that prudence was required in such matters: Steno, Duverney, and Perrault were all very guarded; Dionis was a bit more talkative, but he emphasized the conjectural character of his teleological explanations. As for admiration, it was compulsory, although expressed in general terms in the introduction to each lesson before giving way to more exact considerations.*”°

On the whole, then, rationalistic teleology, as expressed in France at the end of the seventeenth century, avoided the absurd and the sterile. It offered the Christian scientist the chance to combine his faith with his science, while to a significant extent sacrificing the God of the Bible in favor of the God of the philosophers.*?® But it did not turn science away from the search for efficient causes, and it allowed it to believe, on the contrary, in a rational linkage of causes whose guarantor was God Himself. This meant, specifically, that God did not interfere in physical phenomena, except in the well-defined cases of pure miracle. Such was certainly Boyle’s opinion: Once the world was organized and the course of Nature established, the Naturalist — except in a few rare cases where God or incorporeal agents interfere—has recourse to the First Cause only for the general and customary help and influence by which it preserves matter and movement from annihilation and arrest; and in the explanation of specific phenomena, the Naturalist considers only the dimensions, shape, movement (or its absence), and texture, as well as the qualities and attributes implied by them for the small particles of matter.3?”

God did not stand in for natural causes in the ordinary course of nature. This was also Gassendi’s belief, recalled opportunely by Bernier.3?* Accord-

ing to Dodart in 1701, the physicists would not “insert God as if into a machine, *?? and much later Fontenelle would congratulate Ruysch for not

| The New Scientific Mentality 187 pretending, in order to get himself out of a difficulty, “to have recourse either

to God’s will functioning without a mechanism, or to God’s intention of hiding the mechanism from us.” 4°° The praise was at the same time a lesson directed at the physicists of 1731. This was also exactly what Leibniz held against Clarke and Newton: “bringing in a Divinity [Deum ex machina] with no concern for the natures of things.” 4°! For the mentality of the scientists of 1730 was quite different from that of Leibniz, and the influence of English thought had a great deal to do with this evolution. “Admire God’s wisdom,” Leibniz had said, and “know things.” It was taken

for granted at the end of the seventeenth century that these were the two goals of science. Fontenelle declares it with solemnity in the famous text that serves as preface to the entire Histoire de [Académie des sciences: The sublime reflections to which physics guides us concerning the Author of the Universe are not to be counted among its mere curiosities. This, great work, ever more wondrous as it is better known, gives us so grand an idea of its Workman that we feel our minds overcome with admiration and respect. Above all others, astronomy and anatomy are the two sciences that offer us the most unmistakably two great marks of the Creator, the one being His immensity ..., the other His infinite intelligence, through the mechanisms of animals. True physics is raised to the level where it be-

comes a theology of sorts.4°?

“One may even consider, he would later say, “that anatomy has some advantage: intelligence proves still more than immensity.” 4°? Admiration, yes; but a Fontenelle “overcome with respect” is a rather surprising spectacle. And yet, in the course of his Histoire de [Académie and without concern for oratorical effects, Fontenelle does indeed marvel at divine wisdom. Whether the subject was the contraction of the iris,4°* the allotment of muscles obeying the will or independent of it,#° the eyelids of birds,#°° or a dozen other such matters,*°” Fontenelle admired the Creator: “From all that one fathoms in

astronomy, there emerged “a marvelous conformity of the work with the intentions of the sovereign Workman.” 4°§ Dodart was therefore justified in saying that “the most noble use” for physics was to lead us to God.*? As early as 1672, Swammerdam had been exclaiming in admiration at the anatomy of reproductive organs,*!° and Malpighi at the anatomy of plants and their roots.*!! Daniel Duncan had already demonstrated the wisdom of the Creator in chemistry,*!? and Le Clerc had greeted Boyle’s publications with cordial commentaries, underscoring everything that displayed divine wisdom.‘ In this way, they joined hands once more with an old tradition that Descartes had almost interrupted: that medicine always led towards God.‘!* Even the

8 THE SCIENTISTS’ PHILOSOPHY Cartesian Legons de physique ended with a commentary on the necessary exis-

tence of the Creator.* It is easy to understand the satisfaction of the bishop who was one of Vallisneri’s correspondents: “A philosopher who researches and comes to know nature can no longer be an unbeliever.” *" However, it was neither astronomy nor even anatomy that revealed the most astonishing wonders. To the mortification of man, all too ready to place himself at the center of the world and the Creator’s concerns, the study of tiny entities— of the most universally despised creatures — was to display unheard-

of riches to the observer. Not only did the microscope open the door to an enchanted world, so surprising that it had to be seen to be believed, but even the most ordinary creatures evoked admiration and lyricism. “O fair nature,” Frangois Poupart cried in 1693, “what economy in your governance! what wisdom in all your actions! what grandeur in your least productions!” This of the horns of the slug.” The reproductive vessels of this astonishing creature might be compared “to a magnificent grouping that the skilled hand of the sculptor has brought out of a single block of matter.” “18 Although the “tiny worm that is born on cheese” might well be “the basest of all insects, it none the less provides material for a lovely meditation, by showing how nature’s wisdom is displayed in her slightest productions.” #1? And what tender emotion would seize the sensitive reader who, having just admired the digestive system of the leech, read these lines full of promise: “All that we have said up to this point cannot approach the beauties remaining for us to describe,” namely, the reproductive organs of this creature, until then too lightly considered exclusively of medical interest.42° Now, Poupart was not an isolated crackpot: he attended Bourdelot’s meetings and was to enter the Académie in 1699. During a solemn and public session of the Académie des sciences on November 12, 1710, in fact, Méry, the taciturn Méry, began reading a re-

port on the freshwater mussel with the following eloquent assertion: “The grandeur of God bursts forth from all His Works. The anatomists who apply themselves to the study of nature discover every day in the lowest of animals

parts whose structure gives them no less occasion for admiration than the structure of man gives them subject for astonishment.” 4?!

Who, however, could possibly speak of insects better than Réaumur? Swammerdam had unveiled the secrets of their metamorphoses, whose regularity he considered a proof of the existence of God: “Since the reproduction, the growth, and the transformations of insects always occur by rule, who can deny that all the components of the universe are governed in the same

The New Scientific Mentality 189

fashion? Who will not rest in full security under the guardianship of the AllPowerful?” 42? Malpighi, Leeuwenhoek, Vallisneri, and many others had likewise studied the generation of insects and all of them pointed out “the Wisdom and Providence of God even in the most minuscule of living beings.” 473 But they had been particularly concerned with the problem of generation. None of them had been able to devote enough time and attention to studying the behavior of insects and the relationships between their structure and their mode of life. Réaumur devoted detailed and impassioned studies to all these matters, which impelled him to admire the Creator all the more. Nonetheless, he systematically mistrusted admiration, which often makes us see more marvels than exist. He made fun of the intelligence that Pliny attributed to the cuttlefish, Godaert to ants, and most of the naturalists to bees.424 What he did not wish, above all, was for admiration to be accorded to these creatures: it should ascend “to Him who gave them being.” 42° For Réaumur

did not believe in the intelligence of insects: “Each species . . . has, so to speak, only its clever trick by which its can attract our admiration.” Were they even cleverer, Leibniz would still be justified in considering them machines.4?6 Réaumur thus joined ranks with Leeuwenhoek.*?”

It was God, then, whom we had to admire in insects. But how could we not? “Facts such as these would appear admirable even to him who is least apt to admire.” #78 “Can we learn without admiration” of the instinct impelling certain flies to lay their eggs in the hides of certain animals, and of the instruments they made use of in order to do so?4?? How could we not admire “the wisdom of nature” that “shaped with wondrous art” the internal parts of insects, that used “the same skill” to defend them, and that to do this “took care to cloak these delicate parts in different envelopes”? —and whose “attention .. . went even so far as to proportion the strength of these defenses according to the weakness of the internal parts”?43° Could we fail to admire nature's art in keeping sea urchins sedentary? 43! Often, however, “the marvels lavished on the internal structure of insects escape us.” 43? Luckily, “the clever ways that nature has taught [them]” 43? made up for our loss. “There is perhaps no insect that seems to display more intelligence [than a certain variety

of tinea in clothing itself], or shows an intelligence more fit to fill us with admiration. . .. Nothing is beyond the ingenuity that this insect shows.” 474 Réaumur’s sincere, precise admiration was continually aroused by the wonders he discovered. He was, of course, making his own use of a well-worn afhrmation, but it was one whose truth he had himself experienced: the kinds

190 THE SCIENTISTS PHILOSOPHY of knowledge that natural history provided “pleasantly occupy the mind that acquires them; they do more—they inevitably elevate it to admire the author of so many wonders.” 49° Again: I have often experienced palpable pleasures on seeing in detail a part of the wonders that He alone who can perform true ones has lavished in order to vary so prodigiously the species of insects, and in order to perpetuate them. It has seemed pleasurable to me to enable those to enjoy the same pleasures who are capable of feeling them; to procure for them sweet and tranquil pleasures that bring, to him who tastes of them, excellent moral lessons that raise the spirit towards the Being of beings, with whose existence we are too rarely concerned.43°

Insects thus led to God simply through the marvels of their organization and without the necessity of seeing in their metamorphoses an image of the resurrection of the body, as Malebranche and Godaert had oddly thought.**” Fontenelle, who attentively followed the work of his friend Réaumur, shared

his admiration. He appeared even more daring in his handling of final causes *98 and did not hesitate to allude to the “modesty” of the “king” of the bees, who “seeks hiding” when he lays his eggs: “For there is nothing one cannot assume about bees.” 43? Réaumur would openly laugh at this idea, which had been suggested to Fontenelle by a report of Jacques-Philippe Maraldi’s.*4°

But irrespective of whether scientists were sufficiently prudent, insects were not to be marveled at with impunity. The wonders revealed by these minuscule beings, whose kingdom extended indefinitely on the microscopic scale, forced them to consider nature in another light. Insects, despised by the vulgar, were not only admirable, they were more admirable than the rest of nature. They “seem to dispute preeminence, where genius is concerned, with those [animals] that impress us most by their bulk. . . . They seem even to win out over them in cleverness.” #4! “We were obliged to see that the

apparatus of the different parts that the organization of the mite’s body implies is no less great than what is required by the body of an elephant: we even had need of philosophy to understand that large and small have meaning only in relation to ourselves, in order that the insect structures might not appear more admirable than the structure of those animate masses of colossal size. “4? This might already mean that the universe was not created on a scale such as to place man at the center. But it was not sufhcient merely to dispel that illusion in order to return insects to commonplace nature. It had to be understood that “these animal machines” were “more complex, more admirable, and possibly made with greater art than those with which we are most closely involved, and of which we have the greatest idea.” 443 In brief, it had

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to be recognized that insects were more admirable than man. What Réaumur dared not say directly, Fontenelle expressed clearly: “It seems in general that the most admirable of all the animals, regarding mechanism, are those that resemble us the least.” 444 Insects were more interesting than men in the eyes of those who sought to understand the divine wisdom. Fontenelle could say of Malebranche: “An Insect moved him more than all of Greek or Roman history.” #4 It had, then, to be asked: “Given that the Author of all beings took such care for the growth of so many little flies; given that they seem to have appeared so precious to Him; given that He was pleased to multiply them so and to vary their species” ;**° given that he gave them organs such that “the different hydraulic machines thought up by our mechanics could not possibly show us structures so admirable and varied”;**” given that He imbued them with so sublime a geometry that “what is not beyond the scope and, so to speak, the genius of these little Insects is too geometrical and too complicated to have a place” in the Histoire de / Académie royale des sciences,4*® was

it not “tempting to think that the highest Wisdom paid too much attention to simple flies?” 44? Must man not wonder what his place was in the universe,

and whether the Creator of all things might not be the God of insects rather than the Father of mankind? The study of insects and of infinitely small creatures did not simply call into question the physical place of man in the universe, which, after all, had begun with the astronomical discoveries of the early seventeenth century.*°° It did not simply call into question man’s moral importance in the plan of Creation, which was much more serious and made it difficult to hold to any deistic position that was not ready to accept the most naive and the least proven providentialism. Most important, it made a unified and rational vision of the universe far more improbable. Insects baffled the scientists, refused to fit into traditional frameworks, and wrought havoc with the most solid analogies and the most firmly held laws. “Philosophy deems [insects] all the more worthy of its attention in that they seem to have been formed by nature on a very special notion,” wrote Fontenelle in 1699 concerning a report by Poupart on hermaphroditic insects.45! This was already quite a remarkable peculiarity. But more was to come. It was confirmed decisively that among animals, insects “are precisely the ones in which are revealed the greatest number of miracles of mechanics.” *? The freshwater mussel, studied by Meéry, not only was hermaphroditic (“this marvel is by now commonplace”), it was

at the same time father and mother.4°? Then there was the crayfish, whose claws grew back when broken off, “so surprising a fact” that the philosophers

192 THE SCIENTISTS PHILOSOPHY had “refused to believe it merely on the faith of the common people... and it must be admitted that they had cause.” #4 Finally, and in rapid succession around 1740, Charles Bonnet proved the parthenogenesis of aphids, which Leeuwenhoek had only surmised, and Abraham Trembley discovered the regeneration of freshwater hydra. Réaumur felt justified in saying of the first discovery that this was “the greatest peculiarity that natural history has shown us until now, a singularity of interest not only to students of nature but to students of metaphysics as well.” 4°° As for the second, it was still more extraordinary: it “confounds our old ideas,” said Réaumur, “and confronts us

| with new dilemmas concerning the nature of animals and their most intimate conformation. . . . At least it teaches us that all the marvels we have glimpsed in the organization of certain animals are nothing in comparison with those that actually exist.” °° At every turn, nature was undoing conceptions of man. In so doing, it was destroying the foundations of reasoning by analogy, which assumed unity in nature’s laws. It was the observations on the regeneration of crayfish claws and on the parthenogenesis of aphids that led Réaumur to note the weakness of analogy.**” Inasmuch as nature accepted exceptions and anomalies, it was possible to doubt the universality of its laws.*% From then on, one could continue to write in the manner of Leibniz and Malebranche that God acted only in a simple and regular fashion, but it was now a mere philosophic conviction. The study of nature had revealed, on the contrary, the extraordinary diversity of beings and forms. The greatest merit of the divinity lay no longer merely in having “established for the mechanisms of animal bodies a certain general model,” but also, and perhaps especially, in having “diversified them in so many different and no less marvelous ways.” 4° God had lavished marvels in order to “vary so prodigiously the species of insects.” 46° How great, then, was the vanity of those “who measure the marvels of the infinite power of God according to the notions of their senses and their imaginations!” “©! Then, too, we had to add to the existing beings all those that, “already perfectly formed and designed in miniature,” were waiting to develop and be born, “and one may imagine, although still quite imperfectly,

how rich must be the Hand that has sown them with such profusion.” *°? What now dazzled the eyes of the scientist were no longer the order and regularity of creation but rather its wealth and diversity. Man could not claim to impose rules on divine fertility, nor even recognize the laws that it pleased God to follow in the production of beings. “The Author of Nature, wishing in some way to show us that He is the master of the laws and rules that He has established, appears at times to have sidestepped them as if by design.” “6? No

The New Scientific Mentality 193 longer was it in the majestic simplicity of the universe, but rather in the details of “mechanisms” of such astonishing ingenuity that science unveiled the wisdom of God. These wondrous “mechanisms” have already been discussed.*** To the inexhaustible list that could be drawn up, add only the aquatic insect

whose legs were on its back and its mouth turned upward because it fed on insects that swam or walked on the surface of the water,*©° and the lily worm, still more amazing, that could “hide only in its own excrement; but one must

admire how nature arranged everything so that it might do this necessarily and conveniently. It placed the anus above the end of the body.” 46° Thus the God of scientists, after having been the God of mechanism, had become the God of mechanisms. His wisdom no longer shone forth in general and immutable laws, but in a Providence that produced a special solution for each special case. Natural phenomena were no longer the necessary consequences of the laws of motion but infinitely varied expressions of divine foresight. Microscopic discoveries and the progress in entomology had played a considerable role in this intellectual evolution, as has been shown. But after 1710, the influence of English thought greatly added to the acceleration of this mental shift. Boyle had achieved a rather exceptional balance between Christianity, rationalism, and empiricism. After him, English science, faithful to the essential character of the nation, had considerably expanded the role of faith and experience at the expense of reason. The God of the English scientists at the end of the seventeenth century was much closer to the God of the Bible than to the God of the philosophers. Certain contemporaries openly expressed their satisfaction with the change. Thomas Baker, for example, said that his intention was “to take [learning] down from its suppos‘d heights,” because “there is more need of this in an Age, in which it seems to be too much magnifi'd, and where Men are fond of Learning almost to the loss of Religion.” 4°” After attacking Aristotle, Pythagoras, Descartes, and several others, Baker at last found a scientist after his own heart— Newton. He

was, of course, cautious, because attraction, “which, tho it may be true and pious withal, perhaps will not be thought so philosophical. .. . The truth of it is, we may as well rest there.” 46° For it was possible that the cause of weight

would never been found:

After Men have spent a thousand years longer in these Enquiries, they may perhaps sit down at last under Attraction, or may be content to resolve all into the Power or Providence of God. And might not that be done as well now? We know little of the causes of things, but may see Wisdom enough in everything: And could we be content to spend as much time in contemplating the wise ends of Providence, as we do

194 THE SCIENTISTS’ PHILOSOPHY in searching into Causes, it would certainly make us better Men, and I am apt to think, no worse Philosophers.4°?

Newton’s merit lay, then, in having been able to recognize his ignorance and having let God intrude into nature as directly as possible. Baker was not an anomaly in England, as the success of his book certainly proved.*”° He merely expounded with ingenuity ideas that appeared clearly, if in a more philosophical mode, in the famous controversy that set Clarke against Leibniz in 1715 and 1716. According to Clarke, God, in order to act, needed only a pure and simple decision of His will without being impelled by any “sufficient reason.” He did not limit himself merely to the maintenance of the order of things, He intervened in Creation in order to correct its functioning. According to Leibniz, on the contrary, God could not make decisions without consulting His wisdom (i.e., without reason); having foreseen and corrected in advance all the imperfections of Creation, He had no more need to intervene in the natural course of things, and His only interventions were miraculous.4”! For Clarke, God was above all free; for Leibniz, He was above all wise. Clarke accused Leibniz of introducing fatality into Creation; Leibniz accused Clark of introducing disorder into it, by failing to distinguish between the natural and the supernatural. In Leibniz’s view, universal attraction, which could not be explained by the nature of things, was simply a perpetual miracle. In Clarke’s eyes, Leibniz ended up “driving God out of the universe.” 47? Now, English scientists were not disposed to drive God out of the universe. Followers of Boyle, who established a tradition of lecturesermons in which the orator sought to demonstrate God through science, and followers of Newton, who wrote a commentary on Revelation, strove on the contrary to discover in nature, and particularly in universal attraction, the direct and constant intervention of the God of the Bible, setting “on the same spiritual plane general physics, natural religion, and revealed religion.” *”? This state of mind became evident early on in the eighteenth century, with the appearance of a considerable number of works in which the author demonstrated the existence of God and the wisdom of his creation by calling upon the latest scientific discoveries, particularly microscopic discoveries and universal attraction. Newton himself had provided the example, in the general scholium that closes the Principia mathematica. In 1701, Nehemiah Grew’s Cosmologia sacra appeared; in 1704 [actually 1696—Ed.], John Ray published The Wisdom of God manifested in the works of the creation; in 1705, George Cheyne’s Philosophical Principles of religion natural and revealed followed; and finally, in 1713, William Derham published his famous Physico-theology, or a

The New Scientific Mentality 195 Demonstration of the being and attributes of God from his works of creation, soon

followed by an Astro-theology, or a demonstration of the being and attributes of God from the survey of the heavens. It is important to note that these were

not the works of theologians seeking benefit from the fashionable topic of , the day. Grew was one of the founders of plant anatomy and secretary of the Royal Society. Ray was an ecclesiastic, but above all an illustrious naturalist. Cheyne and Derham, while less well known, were nonetheless scientists and members of the Royal Society. It was science that appointed itself to demonstrate the existence of God and His infinite wisdom, and it was science that revealed the attention paid by Providence to every detail of Creation.4”4 The success of these works was considerable, especially in England. Ray’s work went through six editions in ten years; Cheyne’s had five up until 1753. The public snatched up Derham’s Physico-theology, which had three London editions in one year, while the Astro-theology was already being reprinted in 1715. Then the fashion arrived on the Continent. Jean Le Clerc appointed himself the tireless propagandist for these books, publishing dithyrambic reviews one after another*?> and repeating, after Cheyne, that comets “are ministers of divine justice” and “they send us healthful or malignant vapors according to the views of Providence”;#”° that it was sufficient to consider the Moon in order to see the grandeur of God, for the Moon produced tides, and thanks to tides, the seas did not become stagnant, thus allowing fish to live in them and fishermen to earn their livings; thanks to the tides, as well, vessels entered ports. And the amplitude of the tide was just right for these ends: overly weak tides would be ineffective, overly powerful tides would be disastrous. This was why God placed the Moon at precisely the right dis-

tance to produce beneficent tides. And what if God had given us several moons? The result would have been catastrophic: sometimes imperceptible tides and sometimes enormous tides. “One sees therein with what wisdom the Satellite of our Earth was made.”4”” But there was more than just the Moon, there were mountains and the atmosphere, which had the advantage that “Winds form within it, which push Vessels on the Sea.” 478 Truly, “it is through stubbornness of will that people close their eyes to so many marks of the Divine wisdom,” *”° and “the Cartesians, who do not want us to reason about God’s intentions, have meditated very little on this matter.” 48° The

Le Clerc brothers, for their part, had meditated more seriously than Descartes. They had even succeeded in thinking independently, without the aid of their English teachers. Daniel demonstrates that all insects were created for man: the bees for honey, the silkworm, the cochineal, and the purpura

196 THE SCIENTISTS PHILOSOPHY for clothes, grasshoppers for nourishing Saint John the Baptist in the desert, and all the others “to display to us the wisdom and power of the Creator.” #1 As for Jean, he knew perfectly well that if insects were colorful, it was so that we might believe in God.**? But what he could not understand after all these fine reflections was the incredulity of his century, manifestly stricken with a “presumption resembling madness.” 4%

Still, the age did the best it could. It welcomed all this nonsense with the best of wills. The intellectual crisis it was passing through disposed it to

do so quite naturally. All systems had collapsed. “The system of M. Descartes is full of difficulties; that of the new disciples of Epicurus is equally so, and Aristotle’s physics is no more than a Scholastic jargon that defies under-

| standing.” 484 Scientific disputes were turning out to be as sterile as religious controversies and philosophic debates. “He who attacks will always have the advantage; the hard part is doing better.” ®° But was it possible to do better?

Did it not make more sense to give up on understanding and take refuge once and for all in the arms of Providence? This was the opinion of most. There were of course some protests: Hartsoeker wrote to Le Clerc concerning Cheyne’s work to remind him that there were tideless seas that were as healthy and as full of fish as the others, that these very tides, far from bearing vessels gently into ports, often hindered navigation, and that, finally, on the strength

of this sort of reasoning, one might end up saying that God had given us a nose “for the convenience of putting glasses on it,” “8° a remark that Voltaire was not to overlook. But Hartsoeker had been reading the wrong books, and he thought that what we knew about God was “in fact so little that it simply

cannot be brought into the argument and that it hardly extends beyond the notions of the man on the street.” 48” In brief, Hartsoeker was probably a deist, if not worse. Le Clerc defended Cheyne vigorously, and the public gave its approval. John Ray’s The Wisdom of God was translated into French in 1714.88 Derham’s Physico-theology went through five French editions, starting in 1726,*®? and his Astro-theology went through three, starting in 1729.**° The Journal des Savants did indeed say that Physico-theology contained many

“purely conjectural” ideas that did not “carry great conviction”; but in the end, there was much order in it and much that was true.*?! Two years later, Derham’s Astro-theology was warmly praised.*? And already the Continent was rivaling England. Bernard Nieuwentyt published his Existence de Dieu démontrée par les merveilles de la nature, which enjoyed three French editions,

starting in 1725. In 1732, the abbé [Noél] Pluche began publication of the famed Spectacle de la nature, the first volume of which saw two Paris editions

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in less than six months and a pirated edition in Utrecht,*? the first edition having been stolen almost immediately;** and it was reedited endlessly.*?° As Réaumur put it, “a number of authors . . . seem to hope that observations on insects will multiply, for demonstrations of the existence of God multiply accordingly.” 4°° Friedrich-Christian Lesser’s Théologie des insectes appeared in two French translations, in 1742 and 1745. But there were not only insects, and the material was inexhaustible: a Lithotheology, a Testaceotheology, a Petinotheology, and an Ichthyotheology all appeared.*?” What had begun as a pious intention became a bookselling enterprise. Pierre Paupie, the great bookseller

in The Hague, who in 1741 had published a French translation of the Theology of Water by the German Fabricius, announced an entire collection of similar works, to the applause of the Journal des Savants: “We cannot hold M. Paupie too firmly to the commitment he has made to fulfill his pledge to the public as soon as possible.” 49° The vogue for what Daniel Mornet so felicitously called “experimental theology” *”? was not close to dying out in the mid eighteenth century, and we shall have occasion to return to It. Montesquieu admired the system of Descartes, which made “things so easy for Providence.” *°° Many eighteenth-century scientists might have thanked Providence, which made things so easy for them by sparing them unneces-

sary investigations. Derham had clearly explained that one must not “imag- | ine that God gave us Intelligence and Enlightenment in sufficient measure to explain everything. It is enough that we should see phenomena clearly and that we be able to collect God’s Wisdom.” °° Reflecting on causes was a waste of one’s time, and the Journal des Savants praised the English naturalist Henry Baker highly for his “very judicious reflections on the waste one suffers in providing explanations for the phenomena of nature, a waste of time that would be much more usefully spent in collecting or verifying facts and in raising our minds up to the Creator, whose invisible operations are obvious proofs of His Divinity.” °°? In any case, theoretical knowledge was utterly

useless: it served neither the soul nor the body. Who cared about the cause of tides, the Moon’s repulsion or attraction! The “great physicists” concerned with these things were quite ridiculous figures. “Let them go about with their measuring-rods in their hands surveying the distance of the planets and calculating the effects of the forces of motion.” °°? As for us, we would be content to praise God, who made the tides, and to use to the best of our ability the advantages they provide us. For it is evident in reading [Abbé Pluche’s] Spectacle de la nature that God blessed agriculture, trade, and industry, rather than scientific research, and He guaranteed large profits to those who knew

198 THE SCIENTISTS PHILOSOPHY how to put his bounties to use (after having piously thanked Him for them, of course). Thus one sees a devout utilitarianism and a pious mercantilism emerging in France, which powerfully bespeak English influence, but that would come into full flower only in the nineteenth century, with the triumph of the right-thinking bourgeoisie.°°* The greatness of man no longer resided in knowledge, but in trade and industry. The reason for praising God was that He had organized the universe, down to its slightest details, for the comfort, delight, and edification of humanity. Christian thought might well humble man before God, agreeing on this point with deism, but it was obliged by Scripture to leave Him the prime place in Creation. The superiority that was taken away from man, when his reason was denied the power to understand the universe, was given back to him from outside, in a sense, in the form of a free gift from divine goodness, although human nature neither deserved it nor had a right to it. In this way, man’s supremacy in the world and the infinite distance separating him from God were reconciled. But minute examination of the special attentions that the Creator had had for His creation was not entirely without danger. It was all very well, to be sure, to say that bees were created to nourish and edify humankind. Where mosquitoes and fleas were concerned, the argument became more fragile and risked bringing smiles to the faces of freethinkers, who were likewise quite convinced of the weaknesses of the human mind but less persuaded than Pluche or Le Clerc of the eminent place allotted to man in the world. The admirable “mechanism” of mosquitoes bore witness in God’s favor, not in man’s. With this in mind, Father Régnault was careful in enumerating the proofs of the existence of God to place the marvels of human anatomy before those of insect organization,” and Pluche judged it necessary to emphasize human superiority over other arguments and to eulogize human reason on several grounds, a reason that had, no doubt, to know its limits but that nonetheless elevated man very much above animals.*°° Science had no more to gain than religion from this unbridled emphasis on final causes. Réaumur ultimately had to ask for more prudence in affirming the Creator’s intentions: “A most laudable desire, that of showing the author of the universe’s grand ideas and of better displaying the scope of His providence, has led those seeking to cite us for the final causes of facts and findings furnished them by insects to many overly hasty judgments and to much false reasoning.” The divine wisdom “no doubt acted towards an end and for the most noble of all ends. But can we expect to discover the different ends that it proposed for itself in the construction of each of its works, and its special ends in the ar-

The New Scientific Mentality 199

rangement of each of their parts, if it is permissible to speak in this way of the ends of the Being that sees all in a single, identical perspective?”°°” We could say that the eye was made for seeing and the mouth for eating. But we could not even say that wings were made for flying, since certain butterflies were flightless. To suppose that they were made for adornment was “surely to harbor overly petty ideas of the supreme wisdom.” *°* Thus, the scientist, the philosopher, and the Christian came together in Réaumur to condemn the ill-considered zeal of those who emphasized final causes: “We wish to conclude only that we must be extremely guarded concerning the explanation of the ends that He whose secrets are impenetrable proposed for Himself, and that we often give paltry praise to a wisdom that is so much above our praises. Let us describe its productions as precisely as we can—this is the manner of praise that best befits us.” °°? The works of nature were “in truth works that do not yield to reason’s critique, in which there is only subject for admiration, and in which minds such our ours, and even the most perfect of finite minds, cannot possibly see all that is to be admired.” *!° Observe, admire, and remain silent—such should be the attitude of the scientist before the works of God.

For Descartes, man could know nothing of God’s designs, but he could understand the mechanism of nature. For Réaumur and his contemporaries, man could know some of God’s designs, but nature’s mechanism was beyond

him. The God who had dictated the grand laws of movement and then left them to function had become the God of final causes, who had constructed each detail of his creation with an end in mind. Science did not gain from the change, for the use of final causes turned out to be sterile and fraught with dangers. The designs of God were no clearer than before, and nature was no more intelligible to man. The Christian took comfort from his grounding in the promises of Scripture; the Deist was now resigned to being no more than

the tiniest part of an incomprehensible universe. Giving up useless speculations, both were concerned with putting to best possible use the material advantages provided man by Providence, or by the impassive play of the great laws of nature. “All that is well and good,” replied Candide, “but we must cultivate our garden.”

FOR THE SAKE of clarity, three essential aspects in the general evolution of the scientific mentality between 1670 and 1745 have had to be distinguished here. It is obvious, however, that everything was bound together, and that the triumph of observation or reasoning, the passage from general mechanism to

specific mechanisms, and the transformation of a God who ordained move-

200 THE SCIENTISTS PHILOSOPHY ment into an artisan God and Providence were merely interactive aspects of a deep overall transformation in the mentality of scientists and philosophers. It is clear as well that this crisis was not specific to science, and that it appeared in all areas of thought and art, insofar as it represented, speaking in general terms, the passage from reason to the senses, from idealism to realism, from rational abstraction to historical concreteness, from an order guaranteed by

God to natural disorder, from unity to diversity, from the truth to truths, from the absolute to the relative. This was an intellectual crisis and a “crisis of awareness,” which made an issue of man’s place in the universe, and before God, and called into question man’s right to attain the absolute. Even limiting ourselves to the problem of scientific knowledge, it is not very easy in the tangle of facts to discern definite causes in the evolution that we have been describing. We must, however, take note of the importance of what one might call Gassendism, or, in other terms, the persistence of reasonable skepticism regarding the capacities of the human mind. In France, this skepticism kept a philosophical and Epicurean style that lessened its direct influence on the scientific world. Scarcely anyone except Fontenelle was faithful to this spirit. But it is certain that at the cost of a few purely formal concessions, Fontenelle was able to exert a considerable influence on the scientists of his time. Still, Gassendist skepticism wielded its influence above all through the agency of English thought, in which it had easily combined with a Christianity more concerned with God’s freedom than with man’s greatness. And here it is important to note the definite influence of chemistry, a chemistry stripped of its Paracelsian mysticism, but neither yet of its Christian inspiration nor of its liking for experimentation. Boyle, in whom all these tendencies melded harmoniously, played an exceptionally important role. In many respects, he was the anti-Descartes. After him, English science would be experimental, mechanistic, corpuscularist, skeptical, and pious. Political and religious developments in England, particularly the victory of the Puritans, were no doubt also significant here. Be that as it may, it was the example of English science that, from 1660 on, hastened the triumph of experimentation over reasoning in France. It was also England that gave the microscope its full importance and that first became enamored of natural history, at a time when the major preoccupation on the Continent was still anatomy, particularly human anatomy. Finally, it was English science that after 1710 made fashionable the search for specific final causes. At a time when most of the Paris mathematicians were lining up behind Leibniz in the debate between him and the Newtonians, at a time when universal attrac-

The New Scientific Mentality 201

tion was still considered in France to be an unintelligible miracle or a return to occult qualities, Jean Le Clerc appointed himself ambassador of English providentialism. When Maupertuis, Clairaut, and Voltaire finally succeeded in acclimatizing Newtonian attraction to France around 1730, the groundwork had long since been laid. But the true consequences of the introduction of Newton’s thought into France would not be felt until after 1745, at least in the area that concerns us, and that is why I have refrained from dealing with it here, saving this problem instead for the final section of this study. Indeed, the French scientists did not submit to the English influence without resistance. A still lively rationalist tradition, even if largely evident by now only in the taste for clear ideas; a certain basic secularism, more common in Catholic thought, it would seem, than in Protestant thought—at least that of seventeenth-century England; some irritation, at times, at the chauvinism of English science, which Fontenelle referred to in passing,’ and of which Leibniz complained bitterly: all these things had the effect of keeping French scientists from entering upon the paths followed by their British colleagues. And in fact, French thought at first embraced the English spirit in reaction against Descartes. But beyond a certain balance between reason and experi-

ence, between order and diversity, between man and Providence, French hesitations showed themselves. Fontenelle and Réaumur wanted to save reason’s right of surveillance over the plausibility of facts. Malebranche tended to negate man in God, but this God obeyed the eternal order. Malebranche's concern for final causes remained general and rational, and if Réaumur a bit too often found special intrusions of Providence into the world of insects, he would nonetheless protest against the ill-considered use of final causes. But Fontenelle and Réaumur were able to see that the intellectual evolution that they had abetted with all their might had gone further than they had wished. The chimeras were starting to return, as Leibniz had put it, the same chimeras that Descartes was supposed to have slain. In clearly opposite directions, the abbé Pluche, whom we have examined, and Voltaire, with whom we shall deal later, represented the logical fulfillments of this evolution. In fact, what was ultimately being called into question was the very pos-

sibility of a science that might be something other than a mere history of nature or an industrial technology. It is remarkable in this regard to see the mediocrity of English science in the eighteenth century, particularly of the Newtonians, with respect to everything regarding theory. The true heirs of Newton, prior to the arrival of Lagrange and Laplace, were Clairaut and Maupertuis, d'Alembert and Euler. The fact is still more striking in the creation

202 THE SCIENTISTS’ PHILOSOPHY of modern chemistry, where the experimental observations of the English scientists played a key role, but where systematization was a French achievement.” Abandoned to itself, empiricism served the ends of technology better than those of science. Whether they perceived this danger, which all the halfscientists, professors, and journal correspondents who called so resoundingly for experimentation were unaware of, or whether they reacted spontaneously

and by inclination, the great French scientists attempted to maintain the rights of reason. It is certain, in any case, that the life sciences were affected

more than the others by the vogue for empiricism, probably because this branch of science had been more lacking in experimental foundations. In this venture, at least, science had given up knowing the nature of things; it had resigned itself to being henceforth simply a science of phenomena and to no longer knowing anything but facts, whose ultimate causes escaped its grasp. Against the backdrop of this general intellectual evolution, which I have attempted to describe in broad strokes, a certain number of groups or intel-

lectual clans can be seen to emerge. First, there were those who remained attached to the science of 1650: on the one hand, the Epicureans, who shared the modern skepticism about the power of reason; on the other, faithful Cartesians, who persisted in believing that man would one day understand the universe. Both groups wished to know only the laws of motion and the interaction of corpuscles, the origin of all forms. They rejected direct creation, final causes, and visible designs of Providence. But modern science rejected them in turn: the Epicureans were to move into philosophy, and the Dutch Cartesians were to die without progeny. Modern science was the young Académie des sciences. Mechanistic and skeptical, the scientists who composed it believed in the laws of motion, but gave up on understanding their workings in the specifics of living beings. They thought that God had created nature

as we see it, strictly immutable and admirably wise. They knew that they would always be ignorant of something, and especially of what was essential: the essence of beings. Nonetheless, they accumulated the only source of knowledge, facts, and despite themselves, they did not abandon the search for causes, incapable as they were of giving up their loyalty to clear ideas. In this regard, they were more obstinate than their colleagues in London, who relied more readily on the free will of the All-Powerful, who did not sacrifice the Bible to reason, and who easily found consolation for their lack of understanding in the practical application of knowledge or the pleasure they experienced in admiring the Creator in every detail, immense or minute, of His creation.

The New Scientific Mentality 203

In each group, one or more personalities, of whom there were many during that brilliant age, established the tone, while at the same time elevating his own thought above the ideas of the clan. A bad scientist but an engaging writer, cynical, highly colorful, often closer to Rabelais than to Voltaire, Guillaume Lamy embodied the medical Epicureanism that rejected all conformism and served as a link between Guy de La Brosse and the society of the Temple. The stolid Cartesian doctors—Craanen, Drelincourt, Herfelt— remained mindful of the imperturbable self-assurance of their master rather than of his systematic doubt and his scorn for traditional learning. They taught Cartesianism with the same dogmatic seriousness their fathers had displayed in teaching the doctrine of Aristotle. But what could they do in the face of the new thought? It was in that camp that the greatest names gathered, on the side of experience, prudent reason, and piety. That was where one found Swammerdam, who adored in God the admirable creator and the strict lawgiver of insects, with their astonishing metamorphoses; Claude Perrault, Duverney, Méry, Tauvry, to whom anatomy with its infallible mechanisms also revealed God. In the midst of these scientists and attentive to their discoveries, Malebranche and Leibniz erected their great systems, assimilating and giving voice to the tendencies of their time in their personal constructions. For them, God was the center of all things, but was subject to the eternal order, to sufficient reasons. This was the most prodigious effort of human

reason—and also the last—to set itself up, even in God, as the supreme law of the universe. The individual human disappeared, in a sense, in this _ world where only the great laws of the eternal wisdom of the Creator prevailed. Without revelation, the human being would no longer be anything. And Fontenelle, who hardly believed in revelation, but who believed in God the geometrician, consoled himself for being nothing. Perceptive and discreet, able to understand everything, he was something like the philosophical conscience of the Académie. Regarding all the essential points— Creation, mechanism, experience, reason’s limits, the order of nature—he was in agreement with his colleagues. His agnosticism was tempered by a passion for clear ideas: the little that he thought he knew, he wanted to understand. That he

was not Christian mattered little: the God of the Christian scientists who surrounded him was not all that different from his own. On the other hand, everything distinguished him from Newton—and not only the English scientist’s Christian faith, but his entire vision of nature and science. Newton was unable to understand how attraction could be considered an occult quality, given that its effects were visible and measurable. But for Fontenelle, as for

204 THE SCIENTISTS PHILOSOPHY Leibniz, it was an occult quality because it was not explainable by way of mechanics. A free gift of God was not a topic for scientific reflection. One may wonder if, for Fontenelle, a simply incomprehensible fact was still a fact. Now, the special attention of Providence was an incomprehensible fact for man. Newton accepted it; Fontenelle did not. While for French scientists anatomy was proving the mechanical regularity

of nature's operations, the microscope and natural history were displaying the infinite variety of Creation to the English. Réaumur felt a double influence. Like Leibniz, Malebranche, and Fontenelle, he was convinced that he , belonged to a universe whose order was beyond us. Like the English natural| ists, he was continually discovering new marvels, which he thought he understood. While describing them, he was content to admire; on reflection, he mistrusted his admiration. And he mistrusted it all the more in that he could | see that all about him people were admiring ever more and reflecting ever less. During this whole period, science and philosophy were intimately bound together. The thought of Leibniz or Malebranche strongly influenced scientific thinking, as will be seen. But it was science that took the initiative. Reflection on the nature of force and the discovery of differential and integral calculus had been powerful motives in Leibniz’s metaphysical thought. Malebranche’s ideas were influenced by microscopic discoveries. In the overall movement of ideas, which reshaped man’s vision of the universe, science played a very large role. It was science in particular that needed God as the guarantor of the intelligibility and regularity of nature, and of the power of reason. Subsequently, it was science, too, that saw that God’s designs surpassed our reason, and that it was necessary to give up hope of understanding the universe. Whether the object of a gratuitous Providence or neglected by eternal Wisdom, man had in any case been abandoned by God where knowl-

edge was concerned. And yet God remained the author and director of the universe, and man searched tirelessly for justice. He would tire of this incom-

prehensible and distant God, this unknowable order, and would end up by denying their very existence. But that stage had not yet been reached in 1745. Not quite. Diderot was just preparing to write his Pensées philosophiques.

FIVE ee

New Discoveries in Animal Reproduction

UNTIL 1660, as we have seen, all theories and discussions about animal reproduction centered on the notion of sperm, a liquid and apparently homogeneous matter. Galenists and Aristotelians debated the existence of female sperm and the role of male sperm. The new philosophers replaced the idea of faculty-bearing sperm with that of sperm composed of corpuscles. But all of these views remained, in effect, a priori. Hastily conducted anatomical research, without adequate technology and without a true sense of observation, remained too summary to furnish new data for knowledge of reproduction. The appearance on the scene of new instruments, more advanced anatomical techniques, and a new scientific mentality would permit more precise kinds of research, which would lead, between 1660 and 1680, to two essential discoveries: that of eggs in viviparous females, and that of spermatozoa in male sperm. They will be dealt with separately here, along with the doctrines that arose from them, but it is important to remember that they were virtually contemporary, and that the doctrines developed in opposition. Their rivalry was doubtless fortunate, in that it stimulated research, particularly Antonie van Leeuwenhoek’s; but it was ultimately harmful to both systems and held

back their necessary synthesis. At the same time, we must not forget the theory of the preexistence of germs, which weighed heavily on the problem of procreation during this period. But before taking on this last, crucial issue, the facts that served as a foundation and an argument in all discussions involving it need to be set forth.

206 THE SCIENTISTS’ PHILOSOPHY

| Viviparous Animals Eggs and the Ovist Doctrine

“Never has the human body been explored so much as in the past century,"

wrote Pierre Bayle in 1684. “But of all the parts that have been examined with incredible curiosity, certainly none have been more carefully studied than those serving generation.” * In saying “in the past century, Bayle was no doubt thinking of the great anatomists of the period preceding 1650— Fabrizio d’'Acquapendente, Jean Riolan ft/s, Thomas Bartholin, and William Harvey. In Bayle’s place, a modern historian would say “in the previous twenty years.” For it was research undertaken after 1660 that led anatomists to the discoveries of the end of the century, and specifically to the discovery of the eggs of viviparous animals, the foundation of the ovist doctrine. Nonetheless, Bayle’s formulation is significant. Although we see clearly today that Harvey’s idea of viviparous eggs and the authentic—or nearly authentic—egg studied by Steno, Johann van Horne, and Régnier de Graaf had nothing in common, their contemporaries did not draw as clear a distinction as we do. When they learned of the discovery of eggs in viviparous females, they all thought of Harvey, “who had daringly pronounced: Omnia ex ovo.’ *

The earliest ovists, Louis Barles, Christian-Friedrich Garmann, and JeanBaptiste Denis, thought they could use the authority of Harvey, Riolan, and Bartholin to bolster the new doctrine.’ And this contributed to the formation of misunderstandings. Charles Drelincourt in 1684 and Johann Waldschmidt ten years later were still placing Harvey side by side with Régnier de Graaf.‘

What is certain is that the anatomists working after 1650 on reproductive organs were almost all convinced of the existence of eggs in viviparous females. Drelincourt, a man of prodigious erudition, cites them in impressive numbers,’ and the name of a scientist as important as Boyle might be added to his list.6 In most instances, the author simply pointed out the resemblance between a miscarried embryo and an egg. But some of them arrived at more general conclusions or at more precise ideas. For Thomas Wharton, in 1656, the male sperm ascended through the Fallopian tubes into the female testicles, where the mingling of the two sperms was effected, the female sperm being a product of these testicles. The mixture descended into the uterus, which it fertilized, and produced an egg, as Harvey believed.’ Anton Everaerts was an ovist in Harvey’s fashion, but he showed that the female testicles played an essential role in reproduction: a doe rabbit could not conceive when she had

New Discoveries in Animal Reproduction 207 lost them.® In 1666, Father Honoré Fabri likewise maintained that the female provided a germ that becomes an egg.’ But it was with Anton Deusing in 1665 that this pre-ovism perhaps found its clearest expression: in all females, “there are seeds . . . like eggs—so named either in the proper sense or by analogy—,

which are fertilized through union with the male; among these eggs, some are laid before the fetus has been produced ...and others are retained in the uterus and are incubated there until the fetus emerges from them, living and formed.” !° Here, the egg was clearly produced by the female, fertilized by the male, and “incubated” — no longer produced—by the uterus. This pre-egg ovism rested above all on analogy, which had already strongly

contributed to Harvey’s ovism. This analogy was becoming stronger every day, as belief in spontaneous and irregular generation dissipated. All insects, once believed to be the product of spontaneous generation, now came from eggs. Francesco Redi would thus come out in support of Guillaume de ~ Houppeville, one of the authorities in the new doctrine.” All the analogies that we shall see working in favor of ovism were already working in favor of pre-ovism. But they led to a false conclusion, the attribution to the uterus alone of the role played jointly in oviparous animals by the ovary, the egg duct, and the egg itself. Towards 1665, this opinion was “general,” if we are to believe Steno.” It was in any case the opinion that he himself had set forth in 1664.'? It is worth noting as well that Steno, before affirming that female testicles were ovaries, had been an ovist of a type similar to Harvey. This alone

would suffice to demonstrate the importance of pre-ovism in the birth of a theory that, at least at its outset, rested as much upon the new interpretation of known facts as on the discovery of new ones. For the ovarian vesicles, which would henceforth be considered viviparous eggs, had already been observed by Vesalius, and after him by Fallopius, Riolan ft/s, and several anatomists.

It was in 1667 that Steno affirmed the analogy between the “female testicles” of live-bearing animals and the ovaries of egg-layers, an assertion that destroyed the ovism of Harvey and founded a new ovism.'4 Steno had dissected a female dogfish shark, or Squalus, and had observed that the viviparous fish had eggs in its testicles. In fact, Aristotle had already known that this variety of fish produced true eggs, which were in some fashion incubated in the uterus, whence the offspring emerged alive.’? Now, Aristotle had drawn no conclusions from this observation. But Steno already believed that the uteri of viviparous animals contained a kind of egg. The example of the dogfish allowed him to understand that this egg was not produced by the uterus, as Harvey had believed, but came rather from the so-called female testicles.

208 THE SCIENTISTS’ PHILOSOPHY He already knew of the existence of the ovarian vesicles and immediately considered them eggs, analogous to those he had observed in the dogfish shark. “Having seen that the testicles of viviparous animals contained eggs, and having noted that their uterus opens into the abdomen, in the manner of the egg-duct, I no longer doubt that women’s testicles are analogous to the ovary [zon amplius dubito quin mulierum testes ovario analogi sint|, whatever may be the manner in which the eggs themselves, or the matter they contain [sive ipsa ova, sive ovis conteta materia], pass from the testicles into the uterus; as I shall demonstrate, moreover, ex professo, if it be granted me to set forth one day the analogies of genital parts, and to dispel the error that consists in thinking that the genital organs of women are analogous to those of men.” '¢ The error was long-lived, considering that Thomas Bartholin and Jean Riolan fils, among others, had already worked at dispelling it. It is easy to see the importance of reasoning by analogy in all this, and one might say that Steno did no more than clarify and correct the general analogy

established by Harvey. It is understandable that interpreting the final sentence of the text just quoted, Philosophical Transactions attributed to Steno the intention of writing a treatise De partium genitalium analogia, in which the journalist hoped to find proofs of Steno’s assertions.’” It was possible to expect as well that two Dutch anatomists, Régnier de Graaf and Johann van Horne, would soon furnish these proofs. Both were working on male genital organs, and, each fearing to be scooped by the other, they published summary progress reports on their discoveries early in 1668. But Régnier de Graaf’s _ “Epistola” dealt only with the anatomy of male organs.’* It announced a treatise on the same subject, which appeared a few months later, and to which

we shall return.’? As for Horne’s “Observationum .. . prodromus,” it, too, was almost entirely devoted to the male organs.”° But it included some brief remarks on female organs, emphasizing the analogy between the “female testicles” and ovaries: “The entire material work of reproduction depends upon them: for the female testicles are what the ovary is in egg-layers, given that they contain in themselves perfect eggs, filled with liquid, and enclosed in a membrane: I have some preserved in my laboratory that are still swollen.” ”’ “How these eggs are gathered into the uterus and are actualized by the male sperm I shall set forth later, in my treatise,” added Horne, who specified however that the passage into the uterus was effected through the Fallopian tubes, which explained the presence in these tubes of the fetus that Jean Riolan fils had found.?* One may therefore consider Horne to be the first anatomist to have set forth the new ovism clearly. But it must also be noted that in a brief

New Discoveries in Animal Reproduction 209 treatise on anatomy published in 1665,”* Horne had stated that “the [female] testicles are composed of several little bladders bunched together,” and that

there existed “a double conduit that serves to expel the liquid prepared in them.” 74 In 1665, Horne had therefore considered the ovarian vesicles as reser-

voirs for the female seed, which descended into the uterus via the Fallopian tubes. By 1668, and no doubt after reading Steno, he considered these same vesicles to be true eggs. There was no true discovery here, but there was a new interpretation of known facts. Horne is known to have died before being able to publish the complete treatise he had wished to write on the question. It is well established that after 1668, several anatomists took up work on this problem. Steno pursued his observations on the ovaries of women and

of various viviparous females. He did not write them up until 1673, and they would be published only in 1675.”° But he had sent them to Régnier de Graaf, who thanked him for them in 1672.7 Early in 1671, Theodor Kerckring published his Anthropogeniae ichnographica, in which he tells of having found a fetus in an egg descended from the ovary only three days earlier. As we shall see, the work created a great furor. Towards the middle of 1671, Parisian anatomists discovered in a cow's ovary eggs similar to whose described by Kerckring, and Walter Needham, in London, carried out analogous investigations.*” At the end of this same year (1671), Régnier de Graaf took advantage of a new edition of his treatise De succo pancreatico to add an appendix in which he set forth his ideas on the eggs of viviparous animals.?* On the whole, he repeated Horne’s ideas: the ovarian vesicles were eggs that fell into the uterus by way of the Fallopian tubes. However, research was being actively pursued in France (especially at the Académie des sciences), in England, and in Holland.’®

For at the beginning of 1672, despite the assertions by Steno, Horne, Kerckring, and Régnier de Graaf himself, nothing had yet been proven, and many points remained obscure. The successes of the new doctrine did not win the adherence of the most reflective minds. The most important book on the question remained Kerckring’s little publication. But Kerckring made assertions without proving anything: “I have decided,” he wrote, “not to affirm here anything except what the dissection knife, guided by art, has discovered.” *° It was the knife that had discovered the egg. “Who would imagine, if the anatomist’s knife had not discovered it, that the beginnings of man, like those of the bird, are found in an egg? For man comes from an egg. You don’t believe me? Look, then, in the first illustration, at the spectacle that we have often observed.” *! And the essence of Kerckring’s booklet — fourteen

210 THE SCIENTISTS PHILOSOPHY pages in all—consists of illustrations of eggs the size of peas and the skeletons of embryos dissected by the author. The most advanced was a one-and-a-half

month old, but the most remarkable was the embryo discovered in an egg three—at the most four—days after conception. The head was already distinctly formed, and on the whole it looks human in appearance. It was all too good to be true,” and we can easily understand the reservations expressed in the Philosophical Transactions and the Journal des Savants.** Doubtless Kerckring possessed a convenient scalpel and a lively imagination. It was not at all

certain that he had seen what he claimed to have done: it was even entirely possible that he had quite simply plagiarized from Séverin Pineau.*4 Ovism still rested, then, on unfounded assertions and debatable analogies. In the Journal des Savants of March 21, 1672, Abbé Jean Gallois attempted a necessary stock-taking.*’ Two things were certain: there were vesicles in the “female testicles” and what enclosed the embryo in the uterus had the form of an egg. None of this was new. “It remains to be seen, then, if these vesi~ cles that are attached to women’s bodies detach themselves from them, and if this sort of egg in which the embryo is formed is one of those detached vesicles. This is the nub of the whole problem.” *° Now, Harvey had seen the formation in the uterus of the membrane that surrounded the embryo and gave it the look of an egg; the vesicles of the ovary did not seem capable of detaching themselves, and even if they did so, “there is no conduit, in the place where they are, wide enough to afford them passage.” Kerckring’s afhrmation, according to which the eggs descended at a particular time, needed to be verified. “In the last analysis . . . if you want to give the name of ‘eggs’ to all the vesicles found in the reproductive parts, it is true that in this sense there are eggs in women’s bodies, but just as true that one may say that there are eggs in men’s bodies as well.” °” The major difficulty lay in the descent of the vesicles: “In the animals that have been dissected in very great number at the Académie royale des sciences, no one has ever found vesicles that were actually detached.” As for the tubes, one had been found that displayed a cavity. “The conduits do not usually appear to be open in this way, but it could be that they become dilated only at the time of conception.” ** For the | most part, however, Gallois remained skeptical. This critique, noteworthy for its exactness and clarity, moved Philosophical Transactions to return to the question of eggs in its eighty-first issue, which appeared on March 25, 1672.°° The article contained nothing original: a long exposé of Kerckring’s ideas, followed by remarks by Denis (discussed below)

and Gallois. But a last-minute Nota Bene informs the public of Régnier de

New Discoveries in Animal Reproduction 211 Graaf’s “very lately printed book,” which would surely resolve all of the problems, and would soon be the subject of a review.

On the theoretical level, Régnier de Graaf’s new work, De mulierum organis generationi inservientibus tractatus novus,*® did not add much, but it demonstrated the role of the ovarian vesicles in reproduction. After establishing that these vesicles were found in the “testicles” of so great a number of viviparous females that one was authorized to think that they are found in all, de Graaf produced the observations he had made on doe rabbits. He had noticed that after coitus, the vesicles changed into yellow bodies and, above all, he had succeeded in discovering in the horns of the uterus eggs equivalent in number to the yellow bodies in the corresponding “testicle.” Through a series of methodical observations, he had followed the transformation of these eggs into recognizable embryos. The same number of eggs in the horn as vesicles in the testicle, and each egg becoming an embryo: it was therefore proven that the vesicle was an egg and the “female testicle” an ovary.*! The importance of these investigations, which were the first to give an experimental grounding to the new ovism, can readily be seen. Through the certainty of his method and the clarity of his demonstrations, Régnier de Graaf showed his superiority to most of his contemporaries.” The very success of ovism

was to provide other proofs of this superiority. | OVISM HAD, in fact, begun to gain a following even before Régnier de Graaf gave it solid grounding, and the man most responsible for this was obviously Kerckring. We have seen Gallois’s reservations in the Journal des Savants. But Philosophical Transactions was pretty much won over, remaining somewhat skeptical only of the three-day-old fetus.4? And Gallois’s criticisms were to not make any inroads into these ovist convictions.** In any case, Kerckring had found in Paris itself an enthusiastic disciple in the person of Denis, who had translated the Anthropogeniae ichnographica in his Recueil des mémotres et conférences,*° and had shown how plausible ovism really was,

especially in light of the perfect analogy it established with the egg-layers, the number of which had just been so prodigiously increased by Redi’s research.4® Denis’s article caused a considerable stir. If we are to believe a Paris

surgeon, whose testimony dates unfortunately from long after the event, “the opinion on eggs had hardly appeared on the scene than it was considered a most extravagant paradox; the fops made jokes about it; the theater had fun with it; the précieuses took the matter very seriously, and saw in it a deadly outrage against their sex, who were being compared to hens; and nearly all of

212 THE SCIENTISTS PHILOSOPHY those who judge everything superficially placed it in the category of empty visions. *” It is certain, in any case, that Garmann in Chemnitz in 1672, Barles in Marseille in 1674, and Houppeville in Rouen in 1675 all considered Kerckring as the principal authority in favor of eggs. Garmann added Harvey and Steno to the list; Barles named Fabrizio and Harvey, and, in passing, Régnier de Graaf. As for Houppeville, it is clear that his science came from Denis, who is cited along with Redi next to Kerckring.** Also certain is that the value of Régnier de Graaf’s investigations was not immediately apparent, and that they were considered merely confirmation of Kerckring’s ideas. The review in Philosophical Transactions was highly laudatory but glossed over the

essential observations that gave the book all its merit.4? Denis, also full of praise, considered that “the author has performed so many experiments in this area that the reader will find enough in his treatise to convince the most stubborn.” “But,” he adds, “since we have already expanded on this matter in the preceding reports,” the reader needed only go to the book itself.*° The early supporters of ovism, moreover, still suffered from a great confusion of ideas. Barles, in 1674, wrote of the ovarian vesicles: “Monsieur Kerkerin [séc] and quite recently Monsieur Graaf have seen fit to imagine these little balls of water in the shape of eggs: They were not mistaken, certainly, since Hippocrates used this word. . . . Fabrizio ab Acquapendente, and the famous

Harveus [sic], who have dealt with it at length, do not speak otherwise.” *! Houppeville, in 1676, completed his list of ovist authors, adding Horne, de Graaf, and Barles,’* and even naming Swammerdam and Steno. But he had read nothing, or had understood nothing, for he gives a definition of the egg that comes straight out of Riolan fils: “The egg is a natural, organic body, formed of the seed of the male and the female, full of the virtues of both of them, from which an animal is directly formed.” °? Harvey’s ovism prevented people from understanding that of Régnier de Graaf. In 1683 and 1684, Paul Portal, an obstetric surgeon, published some observations that were, in the opinion of the Journal des Savants, “a new confirmation of the system of eggs for the generation of man.” *4 Now, Portal’s observations were of two miscarried embryos “in the form of a shell-less egg.” This was Harvey’s or Riolan’s ovism.”’ And Portal was backed up by physicians like Jean Pecquet** and Jean Pascal.*’

Understandably, this confusion fostered the search for precursors. Harvey was cited everywhere, of course, but also Bartholin, Riolan, and Du Laurens.°* And then there were the ancients, whose authority persisted in 1672: Hippocrates, Aristotle, and Galen had known of viviparous eggs, and this

New Discoveries in Animal Reproduction 213

was reassuring to Denis, Garmann, Barles, Houppeville, and Drelincourt, not to speak of Joubert and Theodor van Almeloveen, who made a profession of finding among the ancients all the inventions of the moderns.” Besides,

had not all of antiquity known about eggs? In 1672, Garmann had begun a history of the egg going back to mythology. This challenged Drelincourt’s erudition: he trotted out the Egyptian and Syrian gods, Venus and Leda, Pythagoras and Orpheus, Empedocles, and so on.®’ To which Garmann, stung to the quick, replied in Oologia curiosa with a dissertation “De loeuf mystique, mythique, magique, mécanique, médical, spagyrique, magirique et pharmaceutique,’ listing all known eggs from the mystical egg of the Egyptians to the golden egg of the pharmacists, by way of Leda and Zoroaster. Schoolboy games played by belated scholars hardly helped clarify matters. As an anonymous author remarked in 1705, the story of the dancer aborted by Hippocrates who gave birth to an embryo in the form of an egg

“leads one to believe that man is formed from an egg; but it does not enlighten one as to whether he has come from what we now call an ovary.” °? Antonio Vallisneri, less patient, railed against those who go about citing this “nice little tale,” this “medical crime of Hippocrates, contrary to his famous oath,” and against those who invoked passages from Aristotle, Theophrastus, Empedocles, Macrobius, or Plutarch to have us believe that the ancients had known about the eggs of viviparous animals. “The only ones missing were the Talmudists, and the whole swarthy race of celebrated visionaries of dim antiquity.’ °° For all of these comparisons served only to make ideas more uncertain. Nonetheless, true or false ovism made rapid progress after 1672. As Garmann put it, “this hypothesis. resolves problems that are otherwise intractable.” The question of female sperm no longer arose, and the “female testicles” regained “their excellence and their nobility.” Congenitally joined twins, and twins in general, were now easily understood, as were sterility, uterine moles [fibroid cysts—Ed.], and women’s ailments, which arose from the decomposition of the egg. Finally —and Garmann considered this a definite advantage—the doctrine of eggs made plausible the iv vitro creation of Paracelsus’s homunculus chymicus. (Garmann’s thinking on this point is none too clear and need not be stressed.) °* Despite all these advantages, resistance was nonetheless immediate and not always based upon scientific scruples, as Houppeville was cruelly to discover. A doctor of medicine from Montpellier and a member of the College in Rouen, he kept abreast of scientific discoveries, at least through reading journals. In the winter of 1674-75, a dissection

214 THE SCIENTISTS PHILOSOPHY was performed on a woman “in whom were found several extraordinary objects, °° which Houppeville took to be eggs. He therefore published a little treatise, La Génération de lhomme par le moyen des oeufs [The reproduction of man by means of eggs], in which he attempted to reconcile Kerckring’s ovism with Hippocrates and Galen. Alas, an anonymous individual, also a doctor from Montpellier and probably a colleague of Houppeville’s in Rouen, wrote a Réponse a la lettre de M. Guillaume de Houppeville, which showed the imprudent physician the horrible impiety of his assertions. Had he not dared to deny spontaneous generation when “venerable antiquity . . . accepted that corruption and decay produce insects and several other animals! And, to line up against you more authentic and more trustworthy authorities than the authority of Monsieur de Redi, will you believe in this matter Saint Basil the Great .. . and Hannibal Rosselius . . . ? If you want others, read Saint John Chrysostom and Saint Augustine.”°* Ovism rested on a mistaken interpretation of the facts. Thus, the present writer had seen a woman give birth to five large eggs. What a fine opportunity for a superficial mind to decide on the truth of ovism! But the present writer was quite capable of seeing that “it was an error of the formative faculty, which, deceived by the imagination of the woman, who had passionately desired at the time of conception to eat the eggs of five lobsters that she had seen brought up from the sea at the port in Dieppe, had thus changed the man’s and the woman’s sperm that was in the womb.” °” But, above all, ovism was immoral and contrary to faith. “Vestal Virgins, who nourish in your bosom a divine fire that is not extinguished even at your death, but that, having been lit by the Holy Spirit, is eternal and immortal! Chaste Maidens, whether you live within the world or you be cloistered, will you endure a Physician who would have you possess an ovary like hens; who would have you lay multiple unfertilized eggs [des oeufs subventanés

et hardelés|? . . . Will you endure this, let us not say without blushing, but without crying vengeance against a doctor who accuses you with impunity of filth and corruption?” °* No, we had to abandon “so pernicious a schism” and decide “with our ancient Fathers,” in favor of the truth of the mingling of the two seeds.®?

The blow was unexpected and hard. Accused of immorality, irreligion, and overt hostility to the ranks of womanhood, the wretched Houppeville almost died of grief. He fell gravely ill, and “attacks of a most malignant fever” would certainly have put him in his grave without the enlightened care and solicitude of his colleagues, who, solemnly assembled as a body on January 27, 1676, condemned the abominable Réponse. Restored to the regard of

New Discoveries in Animal Reproduction 215

his fellow citizens and the affection of his patients, reassured of his own innocence, Houppeville was able to compose another work, in which ovism was defended by Eudoxus and Philotimus against the sophistries of the perfidious Antigenus.”° Facing an adversary who “returns to the old tales of the past,” ”?

Houppeville solemnly afhrmed: “I prefer the truth to Aristotle.”’? He had broadened his documentation and lengthened his list of references. But, as we have seen, he still did not know what a viviparous animal’s egg was, and he had almost died a martyr for a dogma he had not understood. NONETHELESS, ovism made steady progress, and the initial confusions were slowly disappearing. There is ample witness to the success of the theory. As early as 1679, the Journal des Savants noted that “the opinion concerning

the formation of man and all other animals by means of eggs has become so widespread that there are hardly any new philosophers who do not accept ! it today.” ’° This testimony is all the more interesting in that the editor of the journal clearly did not approve of the new doctrine. By 1685, success had given way to enthusiasm: “There is continual exclamation over the theory of the generation of animals through eggs,” the Journal des Savants observed,”4 while Bayle noted that “this opinion has many followers and is very much in vogue. ”? In 1692, it was accepted by “all the modern philosophers,” ’° and in 1697 this system was “at present accepted by almost everyone”;’ it was, indeed, “the only one accepted” (a bit of an overstatement).’® Pierre Dionis, who had long hesitated before accepting the egg theory, had to recognize in 1698 that the mingling of the two sperms was “not generally accepted by all the anatomists.”’? There were even those who passed harsh judgment on it: La Chaume, who was eventually to adopt it, was an eclectic in 1680; in 1697, taking his cue from La Chaume, Jean Fontrailles was considered a belated supporter of antiquity.*° In 1701, Fontenelle could maintain that “the system concerning the generation of man through eggs is quite commonly accepted nowadays, *! an assertion that Jean Palfyn in 1708 and Pierre Amand in 1714 would repeat verbatim.®? Accepted by all the /etterati di for di seno, accord-

ing to Vallisneri in 1710,°? and classified by Albinus in 1711 among the great discoveries of the seventeenth century,54 ovism was considered by Eustache Marcot in 1716 to be “an established principle accepted by everyone.” * The rapidity and extent of ovism’s success deserves to be noted, for it suffices to demonstrate how different the scientific community of 1670 was from the one that had refused to accept the circulation of blood for so long. It would be impossible (as well as tiresome) to provide a complete list of

216 THE SCIENTISTS PHILOSOPHY scientists who, starting in 1675, accepted the ovist doctrine. Nonetheless, a few great names allow us to measure the breadth of its success. To the founding ovists, Steno, Horne, Swammerdam, and Régnier de Graaf, were soon added Malpighi, Margagni, Nigrisoli, Borelli, and Baglivi in Italy; Thomas

and Gaspard Bartholin, Hannemann, and Oelger Jacobsen in Denmark; Daniel Le Clerc and Jacques Manget in Geneva; Ruysch, Verheyen, Isbrand

van Diemerbroek, and Drelincourt in the Lowlands and Holland; Oldenburg, Ray, and Lister in England; and Dionis, Tauvry, and Littre in Paris, without counting philosophers such as Jean-Baptiste Duhamel, Malebranche, Pierre-Sylvain Régis, and Fontenelle. There will also be occasion below to cite many others. The only important adversary encountered by ovism was the doctrine of spermatic worms. Without it, Vallisneri comments in 1721, ovism would have obtained universal assent.8° But we shall return to this.

| Ovism’s major argument, and the one that had already won Jean-Baptiste Denis over in 1672, was the strength of analogy: general analogy, especially with plant life, for Denis van der Sterre®” and Giorgio Baglivi;** animal analogy for Gaspard Bartholin;® and, above all, analogy with insects. Marcello Malpighi’s discovery of slug’s eggs had contributed a new proof of ovism,’° and according to Régis, it was “Monsieur Rhedi in his Treatise on Insects” who had more than anyone else contributed “to the proof that eggs are the principles of all animal generations.” ?' Fontenelle was well aware that ovism was established by “several specific reasons”; but in addition, “general analogy favors it, and this is strong enough a proof for those who know nature's way of behaving. All plants come into existence by way of eggs, to which language has given a different name; all oviparous animals certainly owe their birth to eggs, which the females eject from inside themselves; and it seems very likely that live-bearing animals differ from egg-layers only in that their females have already incubated and hatched their eggs inside themselves.

All plants and most animals have the same principle of generation: would the smallest remainder of animals possess a separate principle?” °? Palfyn and Amand found this text so admirable that they reproduced it verbatim, passing it off as their own! ”° Still, analogy merely “favored” —it did not “establish” —and Fontenelle himself added: “one still has the right to doubt.” The new converts did not always bring new arguments, and the Journal des Savants, complaining at last about always encountering the same stories, ended up dropping the subject from its reviews.*4 Better understood now, ovism raised specific difficulties in need of specific answers. The controversies generated thereby were to render

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service both to ovism and to science by giving rise to important discoveries; but they would end up by rendering extremely fragile a doctrine in which everyone nonetheless continued to believe.

STARTING IN 1672, Swammerdam had been aggressively setting up the new ovism against Harvey’s version.” Drelincourt did the same in 1684.7° Ideas were becoming clearer, and for all the scientists just cited, the egg was

indeed produced in the ovary and not in the uterus. But the first question raised was that of the female seed, of which so much had been said. An objection was raised by Diemerbroek in 1672,” to which Gaspard Bartholin responded in 1677: the liquid that had been considered female sperm came “from a glandular matter analogous to, or even completely the same as, men’s prostates.” °? He was speaking of the vulvo-vaginal glands, which Régnier de Graaf had already described under the name of lacunae, and for which modern anatomy has kept the name of Bartholin’s glands. If one considered the egg the feminine seed, one could say that “the female sperm is double: one serves for pleasure and the other for fecundation.””’ “This opinion is no less improbable than it is novel,” opined the Journal des Savants, which was hostile to the egg theory.’°° Diemerbroek must have found it more satisfying, since he became a convert to ovism with the second edition of his Anatomy. His conversion, moreover, is highly instructive, for Diemerbroek admitted that it was because he like everyone else had once considered the female seed to be “something beyond doubt” that he had proposed “some arguments against the recent discovery of ovaries and eggs, about which until then [he had] not yet heard and [that he had] certainly not seen.” '” In any case, this was exceedingly pardonable in 1672. But in this case, why deny the idea a priori? Many partisans of the double seed were more difficult to convince than Diemerbroek. The master of all of them, the earliest and most vigorous defender of the traditional doctrine against emerging ovism, was Guillaume Lamy. In 1675, in the first edition of his Discours anatomiques, he set forth at length the Hippocratic theory of defluxus: the raw materials of semen were the particles prepared for the nourishment and growth of the parts of the body, but rendered useless by the cessation of growth. “Borne by the arteries, and finding nowhere to settle themselves,” these particles were obliged “to return with the blood through the veins. . . . So that particles return from the head that are proper for the maintenance of the substance of all the different parts of which it [i.e., the substance—Tr.] is made up. In this way, particles return that are proper for the creation of a skull with its teguments, a brain with its

218 THE SCIENTISTS PHILOSOPHY membranes. . . . All these different particles mingled within the blood detach themselves from it by means of the testicles, through which they are strained like serosity through the kidneys; and thus gathered together, they constitute a liquid that is the sensitive and corporal part of the seed.” Likewise for the spirits: “From each of the parts is detached a spirit, which is like the outer layer of the spirit that animates the body, and that resembles it in all ways, as the flame of a candle does the flame of another from which it has been lit.” !©? Seeing alone was enough to convince one of the existence of a female seed. As for the process of generation itself, here it is expressed in clear terms: The two seeds of the male and female, received into the womb at the same time, mingle in such a way that the two liquids become one, and the two spirits a single spirit; it is in this mingling that conception consists, after which the rarefied parts of the seed, namely, the spirits, retire to the center and send out, by the same token, the more coarse and excessive towards the surface; the latter, because of their conformity, link together, and create the membranes in which the fetus is enveloped. Meanwhile, all the particles proper for the formation of the different parts of the body free themselves through the effort of their movement and gather together or separate out according to the conformity or dissimilarity they have with one another. So that those that are proper for the formation of the head will mass together and unite at the place where it must be; those of the chest, the abdomen, and the extremities, do the same

at the same time. . . . Now, the formation, the structure, the disposition, and the connection of all these parts depends principally on the spirit enclosed in the seed, which without awareness, and through the sole necessity of its movements, makes its way through the chaos in which the parts were mingled together, and situates them in the same way they were in the body from which the spirit has come, and from which it has derived the determination of its movements. All the parts having thus been formed, the most rarefied portion of the spirit remains in the heart, which is the center of the animal, and creates there a kind of lightless fire, whose preservation keeps us alive and whose destruction makes us die. There, gentlemen, is the manner in which the fetus is formed, according to the opinion of Democritus, Hippocrates, Epicurus, and all the most illustrious physicists of antiquity. This is to my mind the most plausible and least obscure manner, although many shadows still surround it.!%

I have quoted this text in its entirety because it is both revealing and important. It is obvious that Lamy was a contemporary of Descartes and Gassendi, not of Régnier de Graaf or Steno. In every respect, he turned his back on the science of his time, first of all in his ignorance of recent anatomical discoveries, but also in the importance he so obviously gave philosophical considerations. His mind was still totally imbued with the atmosphere that had surrounded Sennert’s or Gassendi’s debates on the transmission of souls and the struggle of the mechanists against the formative faculty. Lamy was

New Discoveries in Animal Reproduction 219

thirty years late, precisely those thirty years that had seen the birth of modern science.

If he had merely been behind the times, however, he would not deserve our attention. In reality, and precisely by reason of the text just quoted, Lamy was the point of departure for a line of scientists hostile to the new theories. For a long time, these scientists would be recruited mainly from among clinicians, physicians, and male midwives, and not excluding those discussed just below, they remained obscure and lacking in real influence. Nonetheless, they existed. And when, towards 1745, the ovist doctrine, complicated by the theory of preexistent germs, encountered insoluble problems, the theory of preformation in the double seed would be there, ready to offer its explanatory resources. Lamy would then be seen as a precursor by people whose philosophic positions were, moreover, very close to his.

_ In the meantime, Lamy’s opinions first met with a favorable echo among the scientific groups on the margin of official science, particularly in Nicolas de Blégny. Blégny also considered the seed of animals to be “an extract of their _ essence, that is to say, a small composite of their elementary principles.” 1° This seed, “perceptibly homogeneous,” was animated by a soul, the father’s

soul, providing through the action of the animal spirits “an extract of itself | that can become capable of all its functions.” ’°’ The female seed came from the “testicles”; it passed into the womb through “certain canals that have no perceptible cavity.” °° These imaginary and invisible conduits owed their existence above all to an analogy carelessly established with the male organs, the analogy against which Gaspard Bartholin had specifically protested.’°” In 1678, Lamy had published a harsh critique of ovism, to which we shall return. [wo years later, Blégny published in his journal Le Temple d Esculape an article by Duverney that followed Lamy faithfully, both in his critique of eggs and in his theory of the double seed. In 1678, Lamy had to admit the existence of the ovarian vesicles, on which he had been silent in 1675.'°8 Duverney maintained that the female seed came from these vesicles.’°? He even specified that “from each of these [female] testicles derives a canal that goes ~ too directly to the womb and is too closely akin to the man’s vas deferens not to be intended in women for the ejaculation of seed.” ""° As we had been told by Lamy, who along with Blégny constituted the corpus of authorities by whom Duverney swore, “experience shows that the woman does not at all provide an egg, but a true sperm in liquid form like the man.” ™ La Chaume, who in 1680 devoted “three words to destroying the opinion

printed in the Journal des Curteux,’"* did not quote Lamy but shared his

220 THE SCIENTISTS PHILOSOPHY ideas. In any case, a traditionalist doctor did not need Lamy in order to remain faithful to the mingling of the two seeds. Frangois Mauriceau, whose Traité des maladies des femmes grosses |'Treatise on the ailments of pregnant women], published in its third edition in 1681, “truly inaugurates French obstetrics,” 1? saw ovism as “an utterly extraordinary opinion” and thought that in reality the ovarian vesicles contained sperm." For “Monsieur Postel, professor of medicine specializing in anatomy at the University of Caen,” who published an observation in May 1686, in the Journal de médecine edited by Claude Brunet, the so-called ovaries were testicles, and the Fallopian tubes were conduits.'!° Jan Lamzweerde, in Leiden in 1686,!"° the obstetrician

Philippe Peu in 1694 in Paris,” Delaunay in 1698," and the anonymous author of a little anti-ovist book from the same period,'”” all remained faithful

to the double-seed theory, and if Dionis alluded at that time to the relative decline of this doctrine,'’?° Daniel Tauvry had to point out in 1700 that “although old-fashioned, it nonetheless finds defenders.” '*? Even so, he himself saw in it a “Philosophical gobbledygook [that] can impress only persons who remain content with words.”!?? Would this apply to Mauquest de La Motte, “licensed surgeon and skilled obstetrician in Valognes, in Lower Normandy”?! It would not seem so, and yet this well-known obstetrician still believed in a female seed, “infinitely warmer than that of men.” 4 In any case, “it would be hopeless to try to explain how nature functions in order to constitute a body in its entirety or the different specific parts. It is a mystery that has up till now remained impenetrable,” ’”° even to Guillaume Lamy, whom La Motte seems to have held in high regard. But this was no reason to abandon the double seed, which was after all being defended by a well-known man nearly 50 years after the demonstration of ovism by Régnier de Graaf. Nearly all these practitioners, in any case, would have been willing to accept Harvey's ovism. But they refused to look on the “female testicles” as ovaries, and the persistence of this medical tradition was, as noted, extremely important. In fact, the arguments put forward by the supporters of the female-seed theory were not very decisive. It was objected that the supposed conduits probably did not exist. La Motte maintained that one could see them only during coitus. “You are aware, Sir,” another replied, “that invisibility estab-

lishes nothing in proper anatomy.” !° But the partisans of tradition were easily triumphant in the critique of ovism. Inasmuch as they reveal the persistence of an archaic frame of mind, I shall only in passing mention here the criticisms launched against the egg doctrine in the name of the father’s superiority, which it destroys,'?” and in the name of spontaneous generation, which

New Discoveries in Animal Reproduction 221 becomes impossible.'”* The serious criticisms focused on two essential points: the role attributed to the Fallopian tubes, which according to the adversaries

of ovism could neither receive the supposed eggs nor convey them into the uterus; and the very existence of eggs, for the vesicles baptized with this name could not come from the ovary and were not true eggs. It was around these major themes, developed by Lamy, Leeuwenhoek, Duverney, Méry, and several others after them, that an orderly critique of ovism would be established. It is well known that the Fallopian tubes, which the doctors also call the horns of the womb, have one end that opens into the uterus and the other end free: the latter is flared in shape and is called the infundibulum. At rest,

the infundibulum is at a few centimeters’ distance from the ovary. Fallopius, | who had observed this gap, had concluded that the horns could not serve as a canal for seed coming from the so-called female testicles. As we have seen, the partisans of the double-seed theory had, in fact, been obliged to suppose the existence of a special invisible canal, analogous to the male vas deferens. For ovism, this gap constituted a serious difficulty. Steno had resolved it through analogy: the female dogfish shark that he had dissected showed the same gap, and yet the eggs unquestionably passed from the ovary into the womb. Kerckring had preferred to assume the existence of a canal. But Horne, followed in this by Swammerdam and Régnier de Graaf, had explained that at the moment of the dropping of the egg from the ovary, the horn “reaches out through a dilation of its fibers, like the opening of a brass trumpet.” !*” Swammerdam saw fit to criticize Kerckring.’°° Philosophical Transactions had carefully reported this important explanation.’*! Still, Lamy would have none of it. Even if eggs existed, “it would still be utterly impossible for them to enter into the horns in order to descend into the womb.” ?}*? “In truth,” he added, “it is a waste of intelligent people’s time to propose such inconceivable imaginings to them.”’*? Duverney, published by Blégny, determined that the horns were not joined to the ovary, and that they were too narrow for the eggs to pass through.134 Leeuwenhoek, who was a fierce opponent of ovism, perhaps because he saw in it the principal obstacle to the success of the

spermatic-worm theory,’ maintained as well that the horn could not play the role given it.!%° In his view, one would have to be a bit weak in the head to accept the idea that an egg could pass through there.'*’ Against this argument,

by now traditional, Claude Bourdelin in 1691,'°8 Pourchot in 1695,'*? and Dionis in 1698 !*° all raised the authority of Régnier de Graaf and Swammerdam, as well as the fact that the infundibulum of the horn touched the ovary exactly at the moment of the dropping of the egg. But it was in 1699 that more

222 THE SCIENTISTS PHILOSOPHY exact and numerous observations began to allow the ovists to reply. Tauvry explored the anatomy of the tortoise and noted that the horns were thin and loose in this egg-layer, “so that they seem utterly incapable of receiving eggs from the ovary and conveying them into the uterus” —which they nonetheless did.#! From 1701 to 1706, Littre brought to the Académie a series of observations that had allowed him to see the infundibulum of the horn glued to the ovary.!4? On this point at least, the ovists won the match, and Mauquest de La Motte, who in 1718 advanced the authority of Lamy against the role of the horns, got himself roundly contradicted by one of his Paris colleagues.'4? In 1721, Vallisneri felt free to refute summarily the arguments of Lamy and Duverney, repeated by his compatriot Giovanni Sbaraglia: the movement of the horn was a fact no longer to be denied, and it was indeed the horns that conveyed the egg into the uterus.!#4 Moreover, one fact had for some time carried weight: the existence of fetuses discovered in the horns. This is what seems to have persuaded Dionis.!** From 1700 on, tubal pregnancy, already described by Riolan fis, became a well-recognized, but of course incurable, accident.!46 In Vallisneri’s eyes, it was even one of the advantages of ovism.'*

Nonetheless, one question remained unanswered: why were there two ovaries, two horns, and, at least in the human species, generally only one child? Lamy raised the question in 1679, adding slyly: “They are obliged to answer me in their manner of reasoning by way of final causes.” 48 This is a significant reflection, for it reveals to what extent, in Lamy’s eyes, ovism was allied with the new scientific mentality, whose deism and final causes he rejected so violently. Indeed, this is no doubt the deeper explanation of Lamy’s exasperated hostility towards the ovist doctrine. In any case, his question was not easy to answer. Régis ventured the opinion in 1690 that only one egg at a time was mature,'4? but this was an unfounded supposition. In 1699, Auvry imagined that there were two ovaries in quadrupeds so that the movements

produced by locomotion could aid in the descent of the eggs through the tubes,’*° but this was no response to Lamy. And so in 1705, the anonymous author of the Deux parergues anatomiques could easily find in this problem a serious objection to ovism,'*! and Mauquest de La Motte was careful not to overlook it in 1718,!°* whereupon the Journal des Savants had to recognize that “this argument is one of the strongest anyone can bring against the system of generation through the horns.” ’?? Vallisneri himself had to admit that there was a mystery here. Perhaps there were two ovaries so that one might make up for the failure of the other. But it is evident that this explanation 4 la Galen only half satisfied him.'*4 On this point, ovism was reduced to re-

New Discoveries in Animal Reproduction 223

plying: “Because.” But Lamy was right: it was the habit of reasoning by way of final causes alone that had created this difficulty. Still, there was another difficulty, this one infinitely more serious, which was to remain without a satisfactory response and that threatened ultimately to wreck the entire system. Régnier de Graaf, taking his cue from Horne, had baptized as “eggs” the ovarian vesicles. He had managed to discover eggs in the horns, equal in number to the ruptured vesicles. These experiments were not at all easy to reproduce, and most biologists found themselves reduced to taking the author at his word. But no one, not even Régnier de Graaf, had been able to see these eggs/vesicles detach themselves from the ovary to fall

into the horn. In order for ovism really to be proven, it had to be demonstrated that the vesicles were indeed eggs, and that they detached themselves from the ovarian wall. We know today that a demonstration such as this was impossible, because the ovarian vesicles, or de Graaf’s follicles [Graafian follicles—Ed.] as modern science calls them, are not precisely eggs. In addition to the proofs offered by the discovery of eggs in the horns, Régnier de Graaf believed that the very nature of the vesicles justified call-

ing them eggs. They had, in fact, their own envelope, and the fluid they contained coagulates with cooking, like the white of hens’ eggs.’®° This fact alone was sufficient to distinguish them from hydatids and other parasitical vesicles. Steno, in observations published in 1675, also stressed this coagulation.}5° But in 1676, the facts were denied by Girolamo Barbato, who afirmed that the vesicles were often empty, that their contents did not coagulate with heat, and that consequently the vesicles had to be considered glands, and we must remain faithful to the female sperm. Moreover, how could the vesicles leave the ovary in order to fall into the uterus?'°” Here again, however, Lamy was most outspoken. The vesicles existed, but everything the ovists said about them was simply “groundless imagining.” '** “One need only read Graaf and Swammerdam to be convinced of what I say.

Certainly in all the time I have been studying and examining the thoughts of the philosophers, I have never seen any like these for contradicting colleagues, reason, the witness of the senses, and experience, in order to present an unimaginable explanation for something that all intelligent people can explain in a very plausible fashion.” °? “Why, then, is it necessary to abandon the light of day in order to walk in darkness?” '°° If the vesicles were eggs, they could not detach themselves from the ovaries. You might as well ask rivers to flow backwards or rocks to fly. (Lamy was not afraid of oratorical lyricism.) If eggs came from the ovaries, one should be able to find holes in the mem-

224 THE SCIENTISTS PHILOSOPHY brane of the [so-called female] testicles. But one did not find them. Régnier de Graaf said “that one looks in vain for this hole in the testicles, and that it is found only immediately before or after the expulsion of the egg. That is a cheap dodge for a man who fancies himself a writer: is one simply to propose an impossible experiment in order to give authority to the delusions one dreams up?” '*! De Graaf was nothing but an impostor: the vesicles were not eggs and could not come from the ovary. Duverney was scarcely less outspoken than Lamy: ovism was “a system that can have originated only in ignorance, dishonesty, or sloppiness.” 1°? The vesicles were not eggs,'©? and no

one had ever seen an egg come out of the ovary. Lamy and Duverney were avowed opponents of ovism, and the vociferousness of their statements lessened the weight of their criticism. The same could

not be said of Malpighi, who had already declared himself a supporter of Régnier de Graaf in 1672.'°° Malpighi did not, however, believe that the vesicles were eggs either. Upon thorough examination, he thought he had discovered the true egg, or ovulum.'®° But this observation remained doubtful, and when his De utero et VIVIPATUM ovtS dissertatio appeared in 1685,!°”7 what was

seized upon was that the great Malpighi was refuting Régnier de Graaf and was providing arguments for the adversaries of the egg theory. For one would have had to be an a priori ovist, so to speak, in order to accept along with Malpighi that the ovarian vesicles brought into existence the “yellow bodies” that

were to aid in the formation and development of the egg.'6* Leeuwenhoek, who had often examined the tube of an animal after delivery, had always found tiny creatures in it and never eggs. “I hold for absolutely certain and utterly beyond doubt that [the ovists] cannot find an egg,” he wrote.'®? “These imaginary testicles, otherwise called ovaries,” '”° had no function. Males had

useless female parts: the converse was equally possible. “In such an area, it is better for us silently to admit our ignorance and exclaim inwardly: How many are the things whose cause and end we do not know!”!71 What was “as clear as the light of day is that the theory concerning generation through an egg is vacuous and completely absurd.” ’”* Régnier de Graaf and Swammerdam had squabbled with each other until their deaths; but had they lived on, “they would be ashamed of their invention [ipsis figmenti sui puderet].” 17? It would have been hard to be more categorical, likewise more scornful. In 1695, Pourchot defended the egg theory with the already classic, but weak, argument from coagulation.!”4 Dionis, in 1698, maintained without proof that the membrane of the ovary was porous, thus permitting eggs to exit.”? At the Académie des sciences on December 3 of the same year, Do-

New Discoveries in Animal Reproduction 225

dart, an upholder of ovism, recognized the dual difficulty: “The vesicles do not appear to be able to detach themselves from the ovary, and the membrane surrounding the ovary absolutely prevents their escape.” An observation made by a physician in La Rochelle, Doctor Cochon-Dupuis, on the degeneration of an ovary whose vesicles had separated and become swollen with mucus,’”® ought to have permitted resolution of the first difficulty. On the other hand, the academician La Hire had noticed that in certain species of fish, the ovary

was riddled with perceptible holes: “It may be that among other animals these holes are so small that they escape our sight, or perhaps they are created

only at the moment required.”!”” But this was tantamount to falling back on the “impossible experiment” so bitterly criticized by Lamy. The Académie counted among its members a stubborn adversary of ovism in the person of Méry, who had worked with Lamy and was a serious anatomist somewhat feared by his colleagues.’”* In 1701, Fontenelle had to admit that “Monsieur Meéry is not yet entirely convinced by the egg system,” a lovely euphemism. “He finds in it considerable difficulties, which do not seem to him to have yet been resolved.” They want eggs and they only find in the ovaries “little cells full of fluid. A little fluid enclosed in a cell can never pass for an egg... . The supposed eggs have no visible membrane of their own. . . . Moreover, they would have to get out, and the universal membrane surrounding the whole ovary is made of so tight a tissue that it is inconceivable it could ever be penetrated by a round, soft body like one of these eggs.” !”° The ovists assume the existence of the egg’s membrane, which proved nothing, and considered the scars on the surface of the ovary as proof of the existence of eggs. But there were too many of these scars, so that there would have to be far more eggs formed than children born, which was not generally accepted.’*° In order to overcome Méry’s skepticism, Littre multiplied conclusive arguments, sometimes even too conclusive. In 1701, he had found in the infundibulum of a woman’s right horn a vesicle three lines [i.e., about .675 centimeters] in diameter, while the right ovary presented a new scar.'*’ In the left ovary, there were two free vesicles, ready to exit, and the membranes in this part of the ovary were “as thin as onion skin.” Thus the vesicles thinned the membrane before piercing it.'** But most remarkable was a third vesicle in the same ovary, which, “besides a clear and mucilaginous fluid, contained a fetus one-and-a-half lines wide and three lines long, and that was attached to the internal part of the vesicle’s membranes by a cord a third of a line thick and one and a half lines long. I made out very clearly the head in this fetus,

and in the head a tiny opening at the site of the mouth; a little bump at the

226 THE SCIENTISTS PHILOSOPHY site of the nose; and a tiny line at each side of the base of the nose.” All this was visible “merely with the eyes, or by means of a magnifying glass.” '®> After

such an observation, “the egg theory is beyond questioning,” Fontenelle recognized. But, he added, one might wonder if the observers who were “the most zealous for the truth are not sometimes subject to seeing what they believe is true in delicate observations.” !*4 In brief, the fact was implausible and no one believed it. The same year, Littre made another observation favorable to the egg theory, less conclusive but more believable, at least to his contemporaries.'*° The same year too, Pierre Duverney, some of whose observations had been questioned, found eggs half-descended or ready to exit in a cow’s ovary.'*° In 1702, Littre found in a woman’s ovary “as many scars as her parents told me she had had children,” ’*’ this clearly being directed at Méry. In | 1704, the ovary of a woman who had had only one child likewise showed a single scar.'** In 1706, Littre saw an ovary in contact with the infundibulum of the horn and an egg three lines in diameter half-emerged from the ovary. | This time, Fontenelle was convinced: “What Monsieur Littre has seen in this instance is the most secret part of the mystery of man’s reproduction, and the one in which it is the most difficult to catch nature at work.” !®° Still, Méry was “not yet entirely convinced.” He had found vesicles very like the ovarian vesicles in the thick part of the internal orifice of the womb. In 1709, he found some in a man’s testicles, and some of them also became hard with cooking.’?° That was the end of the coagulation argument, professed by Philippe Verheyen as late as 1706.'°’ The problem of the exiting of the supposed eggs still seemed insoluble to Mauquest de La Motte in 1718.!%” Fifty years after Régnier de Graaf, it had still not been proven that the vesicles were eggs, nor that they could become detached from the ovary. Indeed, it was the contrary argument that began to gain ground. Vallisneri, in 1721, carefully went over the whole matter and reread all the authors since Régnier de Graaf. His conclusion was formal: Régnier de Graaf and all his followers had been mistaken in taking the ovarian vesicles for eggs.'°? Malpighi had already said so, and the opponents of ovism, such as Méry and Sbaraglia, had been right on this point. Littre’s observations were without value and had no doubt been carried out on a pathological subject.!9* But Malpighi himself had not been able to see the eggs that Régnier de Graaf described, as large as millet grains.!”* No one had been able to see eggs in the ovary, where they were

practically invisible because of their transparency. They could be perceived only when they had fallen into the horn, for they thickened straightaway.'*° Ovism was nonetheless proven true, because eggs were found in equal num-

New Discoveries in Animal Reproduction 227

ber to the yellow bodies that produced them. Vallisneri himself had demonstrated this in a great number of experiments performed on sows, cows, and ewes.'?” In any case, accidental tubal pregnancies and the one that Nuck brought about artificially in a bitch by tying off one of her horns three days after coupling, manifestly proved the role of the ovaries in reproduction.’ After 1725, the ovist doctrine reigned quite peacefully in the scientific world. The partisans of the dual seed were scarcely in evidence. The most determined opponents of ovism, Méry and Leeuwenhoek, were dead. The very existence of the egg was no longer a matter of debate, but only its role in relation to the contribution of the male parent, spirituous seed or spermatozoid. In fact, the doctrine was exceedingly fragile. The egg had remained invisible,

and it was not impossible to turn to the advantage of female sperm most of the facts put forward by the ovists. The analogy with egg-laying animals and, especially, the theory of preexistent germs, which fitted far better with eggs than with sperm, were perhaps what sustained the system most effectively. Preexistence could also accommodate spermatozoids, but the doctrine of spermatic worms presented serious problems, from which ovism profited.

In the last analysis, ovism was admirably suited to the scientific mentality of the time, and that was perhaps its greatest strength. When this mentality started to change, ovism would be challenged once again.

NEVERTHELESS, ovism did not resolve all the problems raised by animal reproduction. It put an end to an age-old debate, the one that had set Aristotelians against Galenists on the subject of female seed (as Régnier de Graaf was to note with some smugness).'”’ It was henceforth established that the woman furnished something other than menstrual blood to reproduction. But that taught nothing new to the Galenists or to all those who, along with

Descartes and the chemists, accepted the existence of a female seed. Concerning the debate for or against eggs, the chemist Jean Pascal commented in 1681 that “this question has little effect on our notion of leavens.”*°° He continued therefore to speak of female sperm without claiming to deny the existence of eggs. The conversion of Isbrand van Diemerbroeck to ovism enables us to measure the repercussions of the new doctrine with some precision. In 1672, Diemerbroeck believed in the mingling of the two sperms in the uterus.*°! The formation of the embryo took place thanks to an “architechtonic force” acting through the mediation of the spirits.”°? In the second

edition of his Anatomy, Diemerbroeck accepted eggs. For him this meant that the egg contained the female sperm,” and if one could no longer speak

228 THE SCIENTISTS’ PHILOSOPHY of a mingling with the male sperm, it was still the architectonic virtue that assured the formation of the embryo.?°* Diemerbroeck continued to discuss the ensoulment of the fetus, quoting Sennert, Parisanus, and Scripture. With this old-fashioned physician, the fact of accepting the doctrine of eggs re- | solved none of the traditional problems. Even for more modern spirits, ovism left one crucial question unanswered —that of the formation of the embryo—and raised two others—those of the fertilization of the egg and of unfertilized, or wind, eggs. On these three points, debate had been lively since the birth of ovism. We have seen the indignation of the précieuses and the pious wrath of the anonymous writer from Rouen at the idea that women could lay “multiple unfertilized eggs” independently of sexual contact with a man. The same protests were launched in reply to the assertion by Kerckring, picked up by Denis, Houppeville, and Philosophical Transactions, that women evacuated eggs regularly.*°° Kerckring based his opinion on the fact that he had found egos etiam in virginibus [even in virgins], and he had concluded from this that these eggs had been evacuated “in first instance at the moment of the menses, or also in fits of anger [in irae vehementia].’?°® Horne, too, had believed in the spontaneous release of eggs, and Swammerdam had naturally been of the same opinion.”°” It would seem that Garmann shared this belief, since he attributed to the decomposition of an unfertilized egg the “suffocations of the womb” that Guy Patin had thought were caused by the non-utilization of the female sperm.”°® Régnier de Graaf set forth a different opinion. He had performed observations on doe rabbits, coincidentally one of the rare mammals in which coupling provokes release of the egg. Generalizing from his observations, de Graaf maintained that the egg could not leave the ovary unless previously fertilized.”°’ Certain physicians whose practices led them to pay greater attention to women’s ailments continued, however, to credit Kerckrings view. Having used the absence of wind eggs in women as an argument against ovism,”'° Diemerbroeck came to accept the existence of such eggs (ex-

cept among frigid women) once he had been converted on this point. For him, the eggs were borne along in the menstrual blood and could cause uterine suffocations.”"' Drelincourt put forward the same idea in 1684,”"* and the renowned Malpighi did not seem hostile to it in 1685.7"? According to David von der Becke, the egg might drop “under the spur of pleasure.” 714 For Heinrich Herfelt, one was released every month.?!° Philippe Verheyen, in 1712, thought that the periodical evacuations called for examination,”’® and for Edmé Guyot, in 1727, it was the very release of the eggs that brought on these

New Discoveries in Animal Reproduction 229

evacuations.”!” Official science preferred to follow Régnier de Graaf in considering that the menses “must be related to movements fixed by nature and to specific laws that we do not know.” ?"8 Yet a reluctance to accept this lack of

knowledge led to the continued search for final causes. “Perhaps, according to Monsieur Littre’s conjecture, the menses hold open little conduits” destined for the passage of the spirit of the male sperm. Perhaps they functioned to keep free other pipes through which a liquid destined to nourish the fetus would pass. “It is simply a matter of correctly guessing the designs of nature,” Fontenelle concluded, reporting these conjectures.” At least scientists had returned to the idea of relating menstruation to procreation. The problem of the fertilization of the egg by the male seed was much

more important. We may recall that at the beginning of 1668, Horne and Régnier de Graaf had simultaneously published brief reports of their work on the anatomy of male reproductive organs.”?° Horne had attributed a triple origin to male seed: the testicles, the vesicles, and the prostate. But he did not have a chance to return to the question at greater length. Régnier de Graaf, on the other hand, published a more complete work several months later, in which he asserted that the male seed was composed of two elements, which came respectively from the testicles and the prostate; the vesicles served only as reservoirs. One of these elements was active, and the other served in some way as a support and vehicle for it.?”! But these anatomical clarifications did

not go far towards permitting a modification of the traditional idea of the male seed. On the contrary, they confirmed the notion of a seed composed respectively of spirituous, active mobile particles, and coarser, heavier, more passive particles. Thus nearly all the biologists working before the discovery of sperm cells, and afterwards all who did not follow Leeuwenhoek, accepted a definition of the male seed analogous to the one Diemerbroeck gave in 1672

and preserved after his conversion to ovism: “a foamy white fluid imbued with the germinative spirit, created in the testicles and the other spermatic vessels out of arterial blood and the animal spirit for the generation of a like animal.”??? Atomists faithful to Hippocrates, and supporters of the defluxus— Guillaume Lamy, for example—would not have subscribed to this definition of Aristotelian and Galenic inspiration, but since they remained hostile to ovism, there is no need to deal with them here. The debates between Aristotelians and Galenists as to whether or not the male seed participated in the composition of the primitive conceptus would continue, but the ovist doctrine made it difficult to defend the Galenic position, for it was hard to imagine how the male seed could mingle with an egg.

230 THE SCIENTISTS’ PHILOSOPHY Nonetheless, Kerckring asserted that the male sperm in its entirety moved up

into the ovaries through the Fallopian tubes and united there with the egg “in an astonishing manner and [one] not yet explained, but certain nonetheless.”?? Garmann reluctantly followed Kerckring.?** Cornelius Bontekoe followed him without hesitation.?*? The anonymous T. S. J. F. still held to this position in 1713,” and the Journal des Savants recalled in 1718 that it was also the opinion of “Monsieur Ruisch, one of the most learned and renowned anatomists in Europe.” **’ Despite this illustrious support, Kerckring’s opinion encountered difficulties. The mingling was hard to imagine, and above all it was hard to see how

the male sperm in its entirety could reach the ovary through the Fallopian tubes. Certain scientists supposed, therefore, that fertilization occurred in the uterus. This was the opinion of Horne, who believed in the spontaneous re, lease of the egg.??* Drelincourt agreed,’*? and for the same reasons. Here, too,

the authority of Malpighi backed up Horne,”*° but here too Malpighi was not followed by the majority of scientists. It is worth noting, moreover, that Malpighi attributed the fertilization of the egg, not only to the action of the male sperm, but also to that of the female sperm, originating in the feminine “prostate glands,” meaning, most likely, Bartholin’s glands.’*’ In 1701, Johann Berger still believed in fertilization of the egg in the uterus, into which it fell under the effect of pleasure and excitement.”*” Most remarkable, however, was the renewal of Aristotelian influence, even

among scientists who, like those we have just seen, placed the fertilization of the egg in the uterus. For Horne, along with the egg, the female provided all the material for the embryo.”*? The eggs released into the uterus were “actualized by the male seed.” 734 This was a purely Aristotelian formulation, which Drelincourt commented on in Aristotelian terms,”*? and which he could have claimed for his own, because he thought the same.”*° Johann Bohn, in 1686, did not hesitate to quote Aristotle when he said that the mother alone provided all the material for the embryo, and that the male seed brought only “the form and the principle of movement.” ”°” And in 1689, Theodor Craanen considered for his part that the spirit of the male seed alone was “the true former and generator.” *** Again in 1712, Verheyen gave his exposition a very Aristotelian cast, both in the mode of reasoning and in the manner in which he defined the role of each sex, proving that Aristotle had been right in maintaining that the woman did not provide seed.”*? In making a “mingling” of the egg with the material of the male sperm impossible to imagine, the ovist doctrine restored to a place of honor the old Aristotelian doctrine according

New Discoveries in Animal Reproduction 231

to which the sperm acted only through its “spirit.” The spirit was the “spirituous” portion of the sperm, whose existence Régnier de Graaf had confirmed, and that unanimous tradition considered to be the only truly active portion. But this portion now had to act alone, as it had for Aristotle. The Aristotelian tradition, which Fabrizio d’Acquapendente and Harvey had attempted to defend, but that had retreated considerably before the partisans of the dual seed, was suddenly gaining the upper hand. And for adherents of the Hippocratic defluxus, this must have been yet another reason for rejecting the ovist doctrine.

Harvey's authority led a certain number of scientists to believe that fertilization took place through a sort of “contagion,” for which the blood was supposed to serve as a vehicle. Steno had been of this opinion,?4° and Garmann had been tempted by the hypothesis.*41 Gaspard Bartholin openly adopted it. This impregnation of the blood brought about, according to him, the movement of the tubes that attach themselves to the ovary in order to receive the egg, fertilized at the same time in the ovary.’*? Several physicians remained faithful to this thesis, for they attributed the discomforts accompanying the onset of pregnancy to the changes effected by the spirit of the male seed in the blood of the woman. Tauvry found the explanation plausible in 1700,743 and two years earlier, Dionis had not formally rejected it.?44

Joseph Besse accepted it in 1702.74 In 1705, the anonymous author of the Deux parergues anatomiques reproached him with having “made nature act by way of a great detour, she who acts only by the shortest possible route.” 74° This is why Littre, in 1720, seems to have envisaged little conduits to bring the spirit of the male seed from the uterus to the ovary.4” But the contagion theory was hardy. Towards the middle of the eighteenth century, it still found defenders among physicians and surgeons, as witness a book by Jacques Mesnard in 1743,748 and the fact that in 1744 the famous Jean-Baptiste Silva had

no qualms about resurrecting an old thesis of his in which he explained all the accidents of pregnancy by way of the thickening of the blood owing to the admixture of the seminal spirit, a spirit, by the way, that according to him could not migrate up through the tubes.?*° However, this had been the belief of most scientists since Régnier de Graaf,

who had written in 1672: “It is not absolutely necessary that the seed enter either into the womb or into the tubes. It is sufficient that the seminal vapor pass through in order to rise up to the testicles’ eggs... . The semen. . . would never be able to penetrate as far as the eggs . . . so that one must necessarily have recourse to the seminal spirit to get the fertilizer to the eggs.””°° The

232 THE SCIENTISTS PHILOSOPHY respect owed to the observations recorded by Harvey, who had never found male semen in the uterus of the fallow does he had dissected, joined forces therefore with the difficulty of imagining the seed proceeding up the tubes as far as the ovary, there to mingle with the eggs. “Seminal vapor” — the famous aura seminalis—took care of everything. And so it had an immense success. We need only name a few of its partisans: Duncan (1682), Diemerbroeck (1685), Sterre (1687), Craanen (1689), Waldschmidt (1695), Dionis (1698), Tauvry (1700), Becke (1703), Palfyn (1708), Verheyen (1712), Amand (1714), Marcot (1716), Vallisneri (1721), Mattre-Jan (1724), and Bianchi (1743).?*! The

list is certainly incomplete and oddly assorted, but interesting in the very diversity of the names it brings together: chemists like Duncan, mechanists like Waldschmidt, traditional physicians like Diemerbroek, Aristotelians like Craanen and Verheyen, spiritualists like Sterre and Becke, as well as modern scientists like Dionis and Vallisneri.

As a result, it was difficult to agree on the place where fertilization of the egg occurred; furthermore, because the experimental evidence was inconclusive, everyone was free to choose according to his judgment, his professional concerns, and his esteem for other great scientists of the time. But the most important problem —also insoluble—was ow fertilization took place. On this point, a decision based on questionable motives was no longer acceptable. The answers should allow us, and indeed do allow us, to determine the broad tendencies of biology at the end of the seventeenth century. The problem of fertilization was inextricably linked to the problem of the development of the embryo, and the scientists whose conclusions are examined in the pages that follow were articulating their very idea of life here. The account given below is necessarily incomplete, inasmuch as it deals only with scientists who accepted the ovist doctrine, but faithful supporters of the double-seed theory are included for comparison’s sake. Traditional physicians who rallied to ovism but still remained alien to the modern mentality are the first category to note. For them, the egg was simply a new form of the female sperm. In a way, they represented the most “advanced” segment of the great mass of Galenic doctors, who were still part of the medical world, although scarcely publishing much now. For all these physicians, ovists or not, embryonic development remained a question of “faculty.” Next to figures like La Chaume, Nicolas Venette, and all their silent colleagues who adhered to the notions of the dual seed and the formative faculty, we can place Diemerbroeck, a convert to ovism but still faithful to “architectonic virtue” ;?*? Sterre, who likened the role of the male seed to the

, New Discoveries in Animal Reproduction 233 sun’s action on fertile land, and who adopted the theory of the aura seminalis

in part because it allowed us to understand how the Virgin Mary was able to conceive obumbratione Spiritus Sancti {through the shadow of the Holy Ghost];?°? and Craanen, whose thought, while imbued with Aristotelianism, was still not completely untouched by modern influences.?** These physicians were survivors of a bygone age, and few of them wrote after 1700. The tradition of mystical chemistry was much more lively, and it found reinforcement at the beginning of the eighteenth century in the vitalist theories of Georg Stahl. Here again, the difference between chemists upholding the dual-seed theory and their ovist colleagues was slight. For Becke, writ-

ing in 1703, the male seed bore in it the dea of the sire, which explained why mutilations were not hereditary.”°? Helmont’s thought is visible here. The same idea was expressed in 1703 by Martin Heer, who congratulated the

moderns on their anatomical discoveries, but judged that these “new anatomical discoveries should have been joined and combined with the vitalist doctrine of Helmont.”?°° The genital archei of each sex united to become a single archeus, “unique artisan of generation.” 7°” (Heer’s book was, incidentally, the object of a rather unkind review in the Journal des Savants.)”°® Carlo Musitano allowed in 1709 that women possessed a seed “or eggs that must be fertilized, as some believe.” 7”? It mattered little to him, in any case, for the

important point was that “seed is not sperm, but rather a spirit and a soul, which we call life, and that I prove to be of the nature of light.” *°° Stahl’s influence on Andreas Riidiger is already evident in 1716: it was the mother’s soul that formed the fetus, and the proof of this was that a pregnant woman who broke her leg could not heal before the delivery, because her soul could not simultaneously mend the fracture and form the fetus.’®’ Fertilization and formation were exclusively a question of soul, the only principle of life. Here we find ourselves at the polar opposite of the mechanistic spirit, which Riidiger explicitly reproached for leading to atheism.”

Whereas German chemistry, faithful to the tradition of Helmont, was leading to Stahl’s animism, French and English chemistry, influenced by corpuscular physics, were becoming mechanistic.”°? Chemical reactions were ex-

plained by reference to the form of the corpuscles, and they thus became answerable to the universal “laws of motion.” Hence it is difficult to distinguish pure “mechanists” from “mechanico-chemists” among the biologists seeking to explain by way of corpuscular processes the mechanics of fertilization and of the formation of the fetus. Vocabulary sometimes allows us to draw the distinction but not always. In 1672, Denis thought that the male

234 THE SCIENTISTS’ PHILOSOPHY seed acted through its “spirits,” which could be taken, if necessary, in a Cartesian or at least a mechanistic sense.64 On the other hand, Jean Pascal, writing in 1681, was a pure chemist. The spirit of the male seed was an acid, which was corrected in the spermatic vessels, while the woman’s contribution, whether seed or egg, was “composed of salts, whose sparse, dissimilar, and rough parts form an alkaline humor.” ?® And this was proved by mythology and history:

Cupid’s arrows “might be related to the sting of acids,” while “Venus, the most love-stricken goddess of antiquity, came from the sea, as if saltiness had given her these amorous instincts.” Conversely, the nymphs and naiads “who dwelt in fresh water, were chaste, and immune to love.” °° With this point securely established, and with the assumption that each sex contributed particles coming from the entire body,’°’ it was clear that the union of the acidalkali fermentation stimulated and allowed the arrangement of the particles, which could unite only with those resembling them, “because their shapes are disposed in such a way as to permit their easy union.” *°* Thus, there could be no error in this arrangement, even though it was “the blind movement of the seed’s particles” that gave rise to it all.?°° It should be evident how close Pascal remained, despite his chemistry and his somewhat uncertain ovism, to a Hippocratic atomist like Guillaume Lamy. Regarding their conception of life, of course, we must group beside this class of ovists the atomists faith-

ful to the dual seed, who attribute the formation of the embryo to a simple movement of particles. Chemistry provided only supplementary help, without modifying anything basic. The same union between chemistry and corpuscular mechanism can be seen in 1685 in Drelincourt, who attributed fertilization and embryonic formation to the action of “male acido-saline atoms, beyond number,’ *”° describing the movement of the particles as Descartes had done.’”’ Likewise, in 1686, Duncan sought to explain life “through mechanics and chemistry” and assigned to “the genital spirit’ “a certain kind and a particular degree of movement, which makes it fit” to “stimulate a movement in the parts of the egg that changes their shape and their placement, and makes them take on the shape and placement they must have in order to constitute the fetus.” 7”? Although a strict Cartesian in 1687, Herfelt was strongly influenced by chemistry, attributing the formation of the embryo to a “fermentation” (Descartes’s very word), with reference to a chemical phenomenon.’’’ Berger was more rigorously mechanistic in 1701, thinking that the male seed fertilized the egg “through elastic particles.” 774 And was the Cartesian Besse, who spoke of “fer-

New Discoveries in Animal Reproduction 235 mentation” in 1702,””° very far from the anonymous T. S. J. F., who specified that fermentation resulted from the action of the ger salsum (salty vapors] on the oily parts,?”° or from Jean Dartiguelongue, for whom it was a chemical reaction?*”” These biologists all had in common a conception of life as the

motion of elementary particles and an explanation of phenomena through the diversity of shapes among those particles. Aside from Berger, already converted to the doctrine of preexistent germs, these biologists all considered the formation of the embryo as an epigenesis, which brought them still closer to the atomist physicians faithful to Hippoc-

rates and the dual seed. This also explains their disappearance in the early years of the eighteenth century. For the partisans of preexisting germs, fertilization through male seed became something very simple: the penetration of a rarefied vapor into the pores of an already complete embryo. But we shall return to this question at greater length in connection with the preexistence of germs.

The different opinions dividing the scientists of 1700 on animal generation might be classified as follows:

Aristotelians of traditional ilk, opponents of the female seed, had practically disappeared. Some of them had, for lack of anything better, converted to ovism. But they were to vanish without posterity. Among the defenders of the dual seed, Galenists faithful to the formative faculties were still in existence, but scarcely wrote any longer. They had been vanquished by the atomists, pure mechanists or mechanico-chemists, who were sometimes Cartesians, but most often Epicureans and Gassendists; Guillaume Lamy was their standard-bearer. Excluded from official science and in the shadow of the faculties, these atomists were waiting for better days, which they would enjoy after 1745. Finally, the mystical chemists were in the

process of disappearing or evolving. ,

Ovism had almost completely conquered official science. Among the phy-

sicians, there were still some epigenesist ovists, whose traditional, mystical, chemico-mechanistic, and mechanistic tendencies have been examined above. But the same fate was in store for all epigenesists and all proponents of the dual-seed theory: either to disappear or to be silent. Official ovism was being increasingly won over to the preexistence of germs. Finally, a fourth doctrine was setting itself up against both the dual-seed theory and ovism: the doctrine of spermatic animalculi, which must now be examined.

236 THE SCIENTISTS PHILOSOPHY

I Spermatic Animalcuh

Whereas ovism had been long prepared and slowly formulated based on both old and new anatomical knowledge, the discovery of spermatozoa, which were called spermatic worms or animalculi,’’”* was sudden and unexpected. The history of the new doctrine is distinct, however, from this discovery: it did not sufhice merely to see the sperm cells in order for them to be recognized as the essential instruments of procreation and the means of the male parent’s intervention. It took several years for the doctrine to be formulated, as a little familiarity with the texts shows. Study of the texts makes it possible, moreover, to establish the respective rights in this matter of the two Dutch scientists who claimed the glory of the discovery, Antoni van Leeuwenhoek and Nicolas Hartsoeker. Leeuwenhoek was a remarkable personage.’”? A minor civil servant of the city of Delft, he had not pursued formal studies and did not know Latin, which practically cut him off from the science of his time.7°° He devoted all his leisure to an impassioned examination of the most varied objects with microscopes he made himself. Self-taught, he was not blinded by the scientific prejudices of the period, but he often made aimless observations and proved himself inept at organized research on a given subject. Very certain of his observations, he did not suffer contradiction gladly and was not, moreover, too likeable in point of character.?*’ His success with crowned heads seems indeed to have turned his head somewhat.2®? But his exceptional gifts as an observer, the quality of his instruments (which were very simple, but superior to those of his time),”** the exactness of his descriptions, and his keenness of gaze more than justified his success. From 1673 on, Leeuwenhoek published his observations regularly in Philosophical Transactions, to which he had been recommended by Régnier de Graaf.?*4

It was in November 1677 that Leeuwenhoek sent Lord Brouncker, the secretary of the Royal Society, the famous letter in which he established his discovery of spermatic animalculi.”*? A medical student named Ham, related

to Craanen, had alerted him the preceding August to the presence of such bodies in the sperm of a man suffering from gonorrhea. But Leeuwenhoek had then found them in the sperm of a healthy man, examined immediately after ejaculation. “At times more than a thousand of them were wriggling in a space the size of a grain of sand.” 8° This, at least, in the most liquid part

New Discoveries in Animal Reproduction 237

of the sperm. In the thick portion, “they lay almost motionless.” They were so small “that a million of them [milena milltum] would not equal in size a rather large grain of sand.” Leeuwenhoek described their form and their movements with admirable precision. He had also observed other animalculi, still smaller than the first, to which he could attribute no other shape than that of globules. “I remember,” he added in this regard, “having observed some male sperm three or four years ago, at the request of Mr. Oldenburg, and having taken the above-mentioned tiny animals for globules. But because I found the pursuit of this research distasteful, and still more distasteful to tell of it, I kept silent at the time.” Leeuwenhoek expressed his fear that the subject might appear scandalous and gave his correspondent full liberty not to publish his letter if he deemed it preferable. Then he returned to “the specific parts that composed the thick matter in the sperm, to the point of constituting the large part of it.” “I have observed them rather often with astonishment,” he said. And he described them thus: They are vessels, so varied and so numerous, of every kind, large and small, that one cannot doubt that they are nerves, arteries, and veins; indeed, I have seen these vessels in such great numbers that I think I saw more of them ina single drop of sperm than are presented to an anatomist dissecting a subject over a whole day. After having seen them, I was convinced that there exists in no completed human body a vessel that one cannot find in well-composed male sperm. Once, I thought I saw a shape, the size of a grain of sand, that I could compare to a part of our body.

When exposed to the air, these vessels had changed into a watery matter mixed with oleaginous globules, which Leeuwenhoek thought might convey animal spirits. Finally, he had seen appear in the matter particles resembling crystals. “Such are, most noble Lord, the facts that I set out to communicate to Your Honour, and to the rest of the band of erudite philosophers.” It is obvious that at this date Leeuwenhoek did not yet assign sperm cells

any role in reproduction. Ham considered them to be “born of a sort of putrefaction.” ®” Leeuwenhoek himself saw in them a normal constituent of sperm, which was already a remarkable intuition.7** But he thought that the embryo was preformed in the thick portion of the sperm, in the form of those vessels that seemed already to have the lineaments of organs. He thus entered into conflict with the ovist doctrine, and this was the point, far more than the sperm cells themselves, that the reply by the London academicians was to focus on. Brouncker was ill and did not reply personally.?°? He gave that responsibility to the editor of the Philosophical Transactions, Nehemiah Grew, who

238 THE SCIENTISTS PHILOSOPHY wrote to Leeuwenhoek only on January 1, 1678.?°° Grew congratulated “the Observer” in Lord Brouncker’s name and in his own. He urged him to examine the sperm of different animals—dogs, horses, and so on—to see if the animalculi might not differ in number or shape according to the species. As for the vessels in the thick portion of the sperm, Grew did not mask his doubts. He did not see their utility. For, according to Harvey, the male sperm did not penetrate into the womb and, according to Régnier de Graaf, whose experiments were decisive, the embryo was already formed in the egg that emerged from the ovary. “So that the male’s sperm is nothing other than the vehicle of an extremely volatile animal spirit, which imprints a vital contact onto the matter of the embryo, that is, the female egg.” The putative vessels were merely “filaments constructed in disorganized fashion” and analogous to those found in saliva. Like Leeuwenhoek, but for other reasons, Grew was not tempted to assign any role in reproduction to the spermatic animalculi: the embryo was in the egg, and the male sperm was simply the vehicle of the aura seminalis. By the same token, the vessels had no more possible role than the animalculi.

It would actually seem that having sent off his letter of November 1677, Leeuwenhoek lost interest in the question; this would not have been unlike him. But, confronted with Grew’s objections, he got back to work.”?! On March 18, 1678, he answered Grew at length,’”* in a letter that is curious, moreover, in its tone of almost arrogant certainty.*°*? He had examined dog, human, rabbit, and fish (specifically, cod) sperm. Again and again, he had found the animalculi, although in slightly different forms. They were longer in the rabbit and globular in the cod.?*4 But the heart of the letter is an impassioned and disorganized defense of spermatic “vessels” against the doctrine of eggs. Leeuwenhoek had found [these vessels] in human sperm “several times

and much more distinctly.” And he adds: “I venture to say that you and the learned philosophers will lend credence to what I have said about them.”?”° He had not found them in the dog’s sperm, but this was because of practical difficulties in the observation.2®® Grew considered them useless? “As for

me,” replied Leeuwenhoek, “I do not see why nature would have pointlessly created, not only the arteries, veins, and nerves present already in the sperm,

but even parts or at least rudiments of the heart, lungs, and reproductive organs.” *°” Harvey and de Graaf had not been able to find male sperm in the uterus because the sperm quickly turned into water and disappeared.’”* Phlegm, drool, and saliva did not contain similar vessels.??? Leeuwenhoek’s opinion is thus clear: “It is the male sperm alone that forms the embryo, and

New Discoveries in Animal Reproduction 239

the only contribution that the woman can offer is to receive the sperm and nourish it.” 3°° As for the ovaries and the eggs of viviparous animals, Leeuwen-

hoek had examined them “about six or seven years earlier.” Ovism assumed an extremely complex mechanism, and this was contrary to the perfection of nature, “another reason for which I cannot accept these views.” *"' In all this, it was a question only of “vessels.” However, concerning the sperm cells of the cod, Leeuwenhoek came up with an unexpected idea: Seeing these globules, I stopped to consider that there was no reason why nature would not have created in each of these tiny globules the beginnings of all the fish’s vessels, which seemed all the more plausible in that I see in plain water tiny living animals that are several times smaller than the globules of milt, and that certainly have as many organs of locomotion as large fish, despite their small size; there is no reason why, at the moment of fertilization, each particle of the milt should not adhere to and combine with each egg; for we see that if this does not happen, the eggs are sterile.°°?

The intuition here was new, and it is understandable that the reproduction of oviparous fish, with fertilization occurring after the laying of the eggs, lent itself rather poorly to a theory of generation founded on spermatic “vessels.” But Leeuwenhoek’s thought still remained very confused. Grew answered on April 10, no doubt maintaining his position,*°’ and on May 30 Leeuwenhoek wrote him a much calmer letter, which was nonetheless as firm as the preceding one. He had examined rabbit sperm and, although with difficulty, had discovered vessels in it. “And if I had not already seen the vessels in human sperm, I would not have been able to make them out,” he added. Moreover, he had discovered animalculi in dog’s sperm. He main-

tained his rejection of the ovist theory. Nonetheless, he admitted that the “vessels” in the sperm ran a strong risk of rupture in passing from the male to the female; he even wondered if the sluggish animalculi that he had observed

in the thick portion of the sperm had not come from ruptured vessels.>° It would seem that at this point, Leeuwenhoek had no clearly stated position except against ovism. Preformation in the vessels raised many difficulties, and it was not easy to understand the function of the spermatic animalculi. Was Leeuwenhoek possibly getting tired of these investigations? In any case, the end of the letter dealt with other subjects, and eight months would go by before the question resurfaced in his correspondence. Even then, it would not be spontaneously discussed.

At this point we must bring in Nicolas Hartsoeker, who was only 22 in

1678 (some twenty-five years younger than Leeuwenhoek) but had already been passionately devoted to microscopy for four or five years. Hartsoeker

240 THE SCIENTISTS’ PHILOSOPHY had found an easy procedure for making spherical lenses for the single-lens microscope.°” He had seen Leeuwenhoek, and it was to him that he owed the idea of this type of microscope.>% At the beginning of 1678, he established relations with the great Christian Huygens, a member of the Paris Académie royale des sciences, who had returned to his native Holland to restore his weakened health. Following this meeting, Hartsoeker wrote Huygens several letters, whose essential subject was the observation of spermatozoa. The first of these letters is dated March 14, 1678.3°” By the manner in which

the young man apologizes for taking the liberty of writing to the great scientist, it seems evident that this was the first letter Hartsoeker had sent him. He alludes nostalgically to his conversations with Huygens and brings him up to date on his investigations. He describes at length the best technique he has found for observing the animalculi in the sperm, from the making of the lens to the choice of diaphragm. He had seen the tiny animals clearly, and he gives a little sketch. Finally, he had seen a multitude of other animalculi, one hundred to three hundred times smaller than the others and of a different kind. With a compound microscope, he had been unable to see anything. A few days later, on March 21 or 22, Hartsoeker saw Huygens again and showed him the animalculi in the sperm of a dog.?°8 On the 25th, he wrote him once more, stressing the fact that the appearance of the animalculi could vary greatly according to the angle at which they were seen.*°? He gave a rather precise description of them and a second sketch. Then he noted a mistake he had made in the preceding letter: the much smaller animals that he had thought he had seen were simply animalculi like the others, but seen from another angle. Their transparency fostered this type of error: one thought one saw separate bodies or tails, and it was probably these tails that Leeuwenhoek had taken for embryonic vessels. Hartsoeker had seen them as well, and he gave a sketch of them. Finally, he recalled his observation of canine animalculi, which were longer than those of a man, and he announced that he was going to be able to examine the sperm of a horse and of a bull. The next letter, of April 4, gives the results of these observations and of some others.*”® The bull’s sperm was already too old and contained few living animalculi. The horse’s sperm, also too old, contained none at all. On the other hand, the sperm of a cock had contained large quantities in the shape of eels, as had that of a drake. Hartsoeker had attempted to examine cat’s sperm, but “these animals are difficult to handle without gloves.” He added that he would really like to know what Leeuwenhoek had found in rabbit sperm. The following letters, of April 12, May 7, and June 10, brought up

New Discoveries in Animal Reproduction 241

nothing on the question, other than the announcement of a failed attempt with pigeon sperm on April 12.37 On June 24, Huygens left The Hague to return to France, taking Hartsoeker with him. Certainly, then, at the beginning of March 1678 (1.e., nearly a year after the

publication of Leeuwenhoek’s letter to Brouncker), Hartsoeker knew of the existence of sperm cells. It remains to be seen for how long he had known of them. If we are to believe Hartsoeker himself, he had made this discovery as early as 1674, if not even 1673.7!” Until 1677, he had given it no more thought. But then, having arrived in Amsterdam, he once again began his methodical

observations with two friends and found the animalculi not only in human sperm but also in dog, cock, and pigeon sperm. He had shown them to various people, telling them that the fluid examined was saliva. Huygens, home in Holland, had wished to see these animalculi in saliva, and Hartsoeker then told him the truth.?!3 This is Hartsoeker’s account of events. Unfortunately, the letters from Hartsoeker to Huygens that we have just

analyzed do not allow us to accept this story. If the young observer had already made all the discoveries he claimed for himself before meeting Huygens, he would not have failed to display them immediately to his illustrious visitor, along with the technique he had used, instead of doing so in writing once their conversations had ended. Above all, these letters give us a picture of a scientist in the heat of research, setting forth week by week the results of his work, explaining his observational techniques, correcting his mistakes, and announcing the examinations that he intends to perform. It was between March 25 and April 4 that he had observed the cock’s sperm cells, and not, as he said, several months before having met Huygens. It appears obvious in reading these letters that the young man was striving to find in the sperm of various species animalculi whose existence someone had already intimated

to him. As of March 25, and possibly as early as March 14, he knew of Leeuwenhoek’s observations.?!4 Who could have been better positioned to tell

him about them than Huygens himself, who had maintained relations with Leeuwenhoek directly or indirectly for several years,*’* whom one may suppose to have recently been informed of Leeuwenhoek’s discovery, and who would have been eager to have the discovery verified by a young microscopist whose acquaintance he had just made? I believe, therefore, that Leeuwenhoek was indeed the first, after Ham, not only to speak of sperm cells, but to have seen them as well.

Nevertheless, the new discovery remained unknown to the public and even to most scientists. Thomas Bartholin knew about it as of May 28, 1678, as

242 THE SCIENTISTS PHILOSOPHY is testified by a letter published only in 1680.7" Friedrich Schrader had been informed by Ham himself, at a date unknown to us.*!” But no sooner was Huygens back in Paris than he made two presentations to the Académie des sciences, on July 16 and 30, 1678, about the new microscopes he had brought back from Holland. On July 30, he showed the society “an infinite number of tiny animals similar to frogs during their formation. They were zn spermate canis [in the sperm of a dog].”*'* The name of the “finder” was not uttered, or at least was not set down in the paper. The following August 15, the Journal des Savants published an extract from a letter from Huygens publicizing the microscope with a single, spherical lens. After discussing the creatures one could observe in a decoction of pepper,*”” the letter ended thus: One could say that these animals are engendered by some corruption or fermentation; but there are some of another kind that must have another principle, such as those revealed by the microscope in the sperm of animals, which seem to have been born with this sperm, and that are present in such great quantity that the sperm seems to be almost entirely composed of them. They are all of a transparent matter. They have very rapid movements, and their shape is similar to that of frogs before their legs have developed.

This last discovery, which was made in Holland for the first time, seems to be extremely important, and fit to provide occupation for those who are carefully re-

, searching the generation of animals.?°

Leeuwenhoek was not named, but neither was Hartsoeker, and he complained bitterly about it. Enemies of Huygens advised him to write a strong letter to the Journal, and, as Hartsoeker knew French only slightly, they wrote it for him.>?’ But instead of publishing it, the abbé Gallois sent it to Huygens, who called in Hartsoeker and reproached him sharply. Reconciled in the end, the two men collaborated on a second text, which appeared in the same journal on August 29, entitled “Extrait d’une lettre de M. Nicolas Hartsoeker.” It dealt with his microscope, then with animalculi discovered in urine. “He has found some,” added the article, “in the sperm of the cock, which appeared to have more or less this same shape,*”* which as you can see is very different

from that displayed by the little animals in the sperm of the others, which, as we have noted, resemble developing frogs.” *7? The name of Leeuwenhoek had still not been mentioned, but only the discovery of the cock’s animalculi had been expressly attributed to Hartsoeker,**4 and in a manner that made it

clear that this was not the case with the other little animals of different shape. It was nonetheless the name of Hartsoeker, and not that of Leeuwenhoek, that thus found itself attached to the first information published on the dis-

New Discoveries in Animal Reproduction 243 covery of spermatozoa.**° The information, in any case, was very cautiously and even somewhat stealthily presented. Still, the more important of the two articles remains the first, in which Huygens seems to have assessed the possible implications of the new discovery more clearly than anyone else at that date. Could Hartsoeker as early as 1678 have had the idea that the embryo was preformed in the spermatic animalculi? A text by Régis, unfortunately late in

date, invites us to believe so.??° Hartsoeker even claimed as much later on, say- , ing he had spoken about it at that time to Malebranche, who supposedly had not found the idea inconceivable. But we have no proof of this, and we also know the tenuous nature of Hartsoeker’s assertions. It does not appear, in any case, that Hartsoeker concerned himself much with spermatozoa after 1678. Leeuwenhoek was to pursue his investigations alone, unaware even —at least until 1694— of the claims of his young compatriot. Nonetheless, most French scientists were to consider Hartsoeker the sole author of the discovery.*”’ It was perhaps the article in the Journal des Savants that determined Nehemiah Grew at last to publish Leeuwenhoek’s observations, which appeared in Philosophical Transactions no. 142 (i.e., no earlier than the end of February 1679).°** The delay can be explained in various ways. First, no doubt, there was a certain bashfulness occasioned by the nature of the subject.*”? And then, too, there were the difficulties that the Royal Society and Philosophical Transactions were weathering.*°° But it is clear that Grew disagreed strongly with Leeuwenhoek, if not on the observations themselves, then at least on the conclusions that “the Observer” drew from them. Not only did Grew publish mere extracts of the letters received, in some cases very short ones, omitting lengthy elaborations relative to the spermatic “vessels,” he also felt obliged to publish an extract from his own letter of January 1, 1678, along with them, in which he defended the ovist doctrine, and to end the publication with an extract from a final letter addressed to Leeuwenhoek,??! which took up this defense once more and especially attacked the supposed “vessels.” “If these viscous filaments that you present as vessels,” he said, “were truly such, they would be as superfluous to generation as unsuited to it.” For they would be so intermixed in the passage from the male to the female that it would be still easier for nature to produce them in the uterus than to re-

distribute them in their proper arrangement. From an attentive reading of these few pages of Philosophical Transactions, it would have been possible to conclude that Leeuwenhoek had discovered in male sperm animalculi whose usefulness no one could discern and “vessels” on which he had constructed a

244 THE SCIENTISTS PHILOSOPHY rather implausible theory, which he was attempting to set up against ovism. The year 1679 was rather discouraging for Leeuwenhoek. No one in Lon-

don thought of sending him the number of Philosophical Transactions in which his observations had been published.?*? The letters he sent to Nehemiah Grew on February 21, April 25, and June 13, remained unanswered, the first because it never arrived in London, the other two because no one took

the time to reply. On October 13, Leeuwenhoek wrote Hooke to ask what was going on. Was Grew ill or so busy that he could not write? Had the Royal Society been forced to cease its activity?*°? On October 27 (Oct. 17, old style),?#4 Hooke finally wrote back, but by then Leeuwenhoek had heard nothing from London for over a year, and the last letter he had received, the

one sent by Grew on October 3, 1678, had been more of a refutation than an encouragement. This mistrust on the part of official science came close to disheartening him, and, as he explicitly says in a letter of June 13, 1679, to Lambert van Velthuysen, he was tempted to abandon his investigations.>”°

He would continue, however, for “learned people” were encouraging him to do so. Among these “learned people” one can surely count old Constantin Huygens [Christian’s father—Ed.], whom Leeuwenhoek had met just at the beginning of the same month,°*** and who disguised genuine admiration under a tone of paternal irony.

Now it was precisely in the course of this year—1679—that Leeuwenhoek’s ideas were starting to become clear. The letter to Nehemiah Grew that had been lost brought nothing new of importance. But the letter of April 25 was crucial. Not only had Leeuwenhoek discovered sperm cells in the semen of a great number of animals but he had found them in the testicles of a cock. The conclusions he drew from this were substantial: As a result of the observations reported above, I am certain that you yourself and the learned philosophers will agree with me in considering that testicles were made only with the aim of furnishing the tiny animals [i.e., sperm cells—Tr.] and preserving them until their emission. If such be the case, what are we to make of all those particles that I called “vessels,” and you called “fibers,” which I had found in the male seed of man, along with the tiny animals? For a while, I had thought that the fibers or vessels came from the testicles, and that the animalculi were produced in the penis, but here the converse is proven. Thus, those who have always tried to maintain that the animalculi were the product of putrefaction and did not serve generation, are bested. Some of them imagine as well that these animalculi are not alive, but are simply the fire present in the sperm. I think, however, that these animalculi are com-

posed of a number of parts equal to the number attributed by common consent to our body.°?”

New Discoveries in Animal Reproduction 245

For the first time, Leeuwenhoek clearly assigned greater importance to the animalculi than to the spermatic “vessels” 9° and considered them agents of reproduction. The idea of a preformation of the embryo in the sperm cell also began to emerge. But it raised problems, which Leeuwenhoek examined in a letter of June 17 to Lambert van Velthuysen.**? He could not accept the pure and simple preexistence of germs: How was one to believe that a mouse already contained within it the some 10,000 mice that would spring from it in a matter of months? Then it must be that animalculi, too, were born. But whence shall we say comes the seed from which animals are born, a seed that is present in the testicles of animals [i.e., quadrupeds], birds—and apparently human beings —as well as in the milt of fish? And this, in truth, is the only point that I cannot resolve satisfactorily. For if we assume that they have been in our bodies since birth, or even since conception, these seeds, in my opinion, could not have been able to remain there for sixteen years or more without producing life; for 1 am persuaded that, when there reside in our testicles animalculi that have received life, they must desire sexual union. But these are just suppositions, and I am determined to pursue my investigations into the matter to the best of my abilities.34°

Henceforth, one point seemed certain: the embryo was preformed in the spermatic animalculus. But where did the animalculus itself come from? That was the question that would not go away, and one to which Leeuwenhoek was not destined to find an answer during the year 1679. His investigations were, however, slowly emerging from obscurity. On April 27, he had sent Constantin Huygens a copy of his letter to Nehemiah Grew of the 25th. On May 4, the kindly Constantin sent it to Paris, to his son Christian, who read it on May 10 before the Académie des sciences, where its effect was considerable.3#! Like the one sent to Grew, the letter included the examination of the cock’s animalculi previously mentioned, and an evaluation of the number of animalculi contained in the milt of a cod, a number that turned out to be greater than that of Earth's entire human population. It seems that this computation, to which Leeuwenhoek had devoted himself “for fun,” 34? contributed greatly to the success of the letter, rather than the ideas expressed on the role of animalculi in generation, ideas that Duhamel did not consider necessary to include in the minutes. The learned company was especially impressed by “this incredible multitude of insects.” For its part, the Royal Society did not remain indifferent. Greatly taken in 1678 with animalculi in the decoction of pepper,*# it obviously could not have been unaware of Leeuwenhoek’s letters, especially after their publication in Philosophical Transactions. Yet not until June 12, 1679, almost a year after the

246 THE SCIENTISTS PHILOSOPHY Paris Académie, did it examine these animalculi, which were presented to it by Dr. Slare and introduced by Hooke, who undertook the adjustment of the microscope.?44 On July 10, Hooke read a letter to the Society that Leeuwenhoek had sent Grew on April 25, the same whose contents had been presented two months earlier by Huygens at the Académie.3* Finally, on July 17, Hooke reported to his colleagues on an unfortunate attempt he had made to examine spermatic animalculi in a calf: he had found nothing, perhaps because the animal was too young or because the observation had not been performed soon enough.?4° The reactions of the company are not known. What is sure is that the letter from Hooke to Leeuwenhoek, sent at the end of October, asked “the Observer” to examine both fertilized and unfertilized eggs under a microscope.*4” This research would indeed have been able to provide important results, but it was not in the direction of Leeuwenhoek’s investigations. Leeuwenhoek did the examinations requested even so, but he found nothing to distinguish a fertilized egg from any other.**8 In the following letters, he spoke of other things.>#? Finally, in his letter of April 5, 1680, he related an important discovery that answered the unresolved question about the origin of the animalculi. In examining the testicles of a rat, Leeuwenhoek had discovered smaller and undeveloped animalculi along with normal animalculi. Thus, the animalculi were not preexistent—they were born, coming probably from an egg, and they grew: But what can we say of their origin: Are we to imagine that the seed of these animalculi is already existent, even at the moment of conception, and that this seed is stored inert in the testicles of a man until he has attained the age of fourteen, fifteen, or sixteen years, and that these animalculi come to life or are adult only at that moment, and that then there is a possibility of generation? I leave this question to others.°*°

The final sentence was not a rhetorical formula. Leeuwenhoek had arrived

at a terminus beyond which microscopic observation did not allow him to proceed. So he stopped. He had constructed his system, at least in its essential point: animalculi were born or attained an adult state at the moment of puberty, and it was they that contained the embryo. The rest was a matter for theory and did not concern him. In fact, Leeuwenhoek was no more able than anyone else to resist the temptation to theorize. But he was always tempted

to it by others, most often by his contradictors. From April 5, 1680, until January 22, 1683, Leeuwenhoek devoted his correspondence to other kinds of research and was content to mention in passing the spermatic animalculi he had discovered in different insects and to reaffirm their role in generation.*”! Leeuwenhoek’s letter of January 22 was probably provoked by the publi-

New Discoveries in Animal Reproduction 247

cation of the Dutch edition of Régnier de Graaf’s De mulierum organis.*° Leeuwenhoek began with his regular criticism of ovism: the supposed eggs could not get out of the ovary, and the Fallopian tube could not carry them to the womb. Leeuwenhoek was now able to oppose this unsound system with his own fully developed one. “A human being does not come from an egg but from an animalculus.” There were male and female animalculi. Their

great number was no objection, for a tree also produced a great number of seeds. The animalculus established itself in the womb, which had only two or three sites suited to receive it, and the first animalculus installed smothered the others by immediately beginning its transformation, “which is to say that its skin will serve as afterbirth, and the interior of the body of the animalculus will take on the form of a human being, prepared in advance with a heart and other internal parts, and possessing truly the completeness of a man.” *?? The animalculist doctrine had been born: it had taken Leeuwenhoek five years to create it. Francis Aston, the secretary of the Royal Society, replied on February 27, 1683, telling Leeuwenhoek that his system was highly ingenious, but that it would encounter many gainsayers.**4 Events were to justify this prediction to the full.

The scholarly world had maintained prudent reservations regarding the spermatic animalculi, whose usefulness appeared very difficult to define. If we are to believe Robert Challes, the success of animalculism was extraordinarily

sudden and powerful: after 1682, “all clever people renounced the ovaries” and were converted to animalculi. But Challes’s testimony is from considerably later.*°? We can only conclude from it that certain minds in Holland had already considered the preexistence and encasing of germs in the sperm cell.3°° We may certainly believe Challes when he tells us that research was being carried out in Paris on the subject at that time.*”” For Jean-Baptiste Duhamel tells us that Leeuwenhoek’s observations were being repeated, in particular at the Académie.*** “T have been assured,” Dionis was to write later,

“that the gentlemen of the Académie had seen [animalculi] in the sperm of men, dogs, ducks, etc.” °°? In 1690, Régis specified that Wilhelm Homberg, renowned for his microscopes,?® had “passed on to him the manuscript of a treatise he has written on the generation of animals according to the same principle, and he backs up this opinion with such probable reasons that if it still seems surprising, it is only because it is new.’ °°’ One cannot say, then, that the scientific world in Holland, England, or France was indifferent to the discovery of spermatic animalculi. But neither can one say that it displayed great enthusiasm. Ihe English scientists Nehemiah Grew, Robert Hooke, and

248 THE SCIENTISTS PHILOSOPHY Francis Aston had become interested in animalculi, but had refused to follow

along with Leeuwenhoek where it was a question of making them the agents of procreation. “Highly ingenious system, but destined to encounter many ' gainsayers’: such was the verdict. Publicly, the Royal Society through the pen of Grew had specifically expressed its adherence to ovism. In France, everyone was careful not to express anything publicly. Homberg was an animalculist, but his treatise was not published, and the astonishing silence of the Académie on the subject of sperm cells has already been mentioned. Even before Leeuwenhoek had fashioned his system, French scientists had refused to believe that the animalculi were living beings:%°? these so-called animals were merely particles stimulated by heat.3°? What is more striking than the reticence (after all, understandable) is the kind of half-silence maintained concerning the discovery. This half-silence can be explained at the same time by the mistrust of the scientific community and by the fact that several important letters by Leeuwenhoek remained unknown to the public: Philosophical Transactions ceased publication after no. 142, and Philosophical Collections, which temporarily replaced it, appeared regularly only after December 1681. Besides, the editor, Robert Hooke, did not consider it urgent to publish letters devoted to the animalculist theory: hence they barely started to appear in 1683.3°4 Finally, publication in fragmentary and disorganized form did not make the diffusion of a thought that was still uncertain of itself any easier. In 1686 and 1687, the first collections of Leeuwenhoek’s letters appeared, the first in Dutch,?® the second in Latin.3°° The Dutch edition, which was | likely to reach only a limited public and included only six letters, was the object of two long reviews in the Bibliotheque universelle et historique, edited by Jean Le Clerc.3*” Already, the animalculist theory was being carefully expounded. The far more complete Latin edition filled the gaps in information on the question and put everything within reach of all European scientists. Here, too, Jean Le Clerc gave a useful, if briefer, review.2°* The doctrine of spermatic animalculi was finally emerging from the shadows that had surrounded it. From November 1687 to January 1688, Giovanni-Maria Lancisi, a Roman doctor, discussed it in correspondence with Malebranche,*? who had become something of an authority on everything pertaining to the infinitely small. The Dutchman Benjamin Broeckhuysen had certainly heard of it in 1687 but does not seem to have understood very well what was involved.>”

| Régis, in 1690, knew of the doctrine through Hartsoeker and Homberg,*”’ but it was from Leeuwenhoek that George Garden adopted it—at least in the main—in 1691.°”” The aging Caspar Posner referred to it in 1692.°”* No

New Discoveries in Animal Reproduction 249

doubt because of the increasing stir created around it, Hartsoeker was impelled in 1694 to claim priority in its discovery after a silence of more than fifteen years.3”4 At his instigation, the Journal des Savants published a review that set forth the new idea at length.*’”? Now it had become impossible to speak of generation without referring to spermatic animalculi or “worms,” and Claude Brunet was astonished in 1697 that Jean-Baptiste Verduc did not mention them.?”° Pierre Dionis did not overlook them in 1698%”” nor did Delaunay.*”® Martin Lister's attack in the same year,°”° as well as Francois de Plantade’s hoax the following year,**° testify to the dissemination of the doctrine. In 1700, Nicolas Andry published his De la génération des vers, in which he proudly adopted the new theory. This book, which went through several editions, was successful throughout Europe and made its author one of the authorities on the new system.**! Etienne-Francois Geoffroy’s thesis in 1704 was a medical and secular event,**? and the noisy quarrel that set two doctors in Caen— Pierre Ango and Lecourt—against each other in 1712 awakened echoes in the Journal des Savants, which sided unambiguously with the animalculist Lecourt.*** Confronting a somewhat inert ovism, which drew its

strength from universal consent rather than from the weight of its proofs, animalculism was finally becoming an adversary to be reckoned with. This evolution had been slow, and among those who spoke of spermatic animalculi before 1700, there were relatively few who had observed them personally.

Régis, Posner, Brunet, Dionis, and Delaunay clearly knew of them only by hearsay. After 1700, the situation gradually changed. Observations became more numerous in England; in France, where Joblot showed the animalculi to a number of French and Italian doctors; and in Italy, where Antonio Vallisneri examined them in company with Louis Bourguet.?*4 Leeuwenhoek was then able to rejoice at seeing them accepted by more and more scientists.*® Nonetheless, in order to see them, one had to be skilled in microscopic examination or acquainted with someone who was. This difficulty, combined with the various circumstances mentioned, explains why the doctrine spread so slowly, especially before 1700: so slowly that in 1690, Régis peremptorily set it aside on the grounds that “this matter has not yet been examined thoroughly enough.*** Dionis spoke of it as “very new” in 1698, finally deciding “that this deserves confirmation”;**’ in the same year, Lister still spoke of a “new hypothesis.” **° Everything conspired against Leeuwenhoek: scarcity and disorganization in publication, extreme difficulty in verification, and

_ legitimate mistrust on the part of a very recently established scientific mentality confronted with so unusual a doctrine. It is not surprising, then, that it

250 THE SCIENTISTS’ PHILOSOPHY took twenty years for animalculism to assume its place among the great theories of generation. Slow in formulation and in dissemination, the doctrine of animalculi was also slow in finding adherents. Francis Aston had made no mistake in promising Leeuwenhoek a large number of gainsayers. No sooner was the doctrine known than it posed several major difficulties, some of which were to turn out to be nearly insurmountable. As noted, the first objection lodged against animalculi in the sperm concerned their very existence. In 1680, Leeuwenhoek was already protesting at those who accused him of having observed poorly and of having mistaken particles set in motion by heat for living creatures.>*? I have already cited some of those who simply rejected animalculi.°?° This variety of criticism

was enduring. In 1698, Dionis puts forward the opinion that “in the sperm there could have been little fibers destined to form the bones and the coarser parts of the body, which, moving about while the sperm was still warm, may have been taken for animals.” *?! This is reminiscent, in any case, of the “vessels” that Leeuwenhoek thought he had seen. Tauvry sustained an analogous opinion in 1700, which got him a lengthy refutation from Andry.*”” After-

wards, this type of attitude became less frequent. Nonetheless, it was still found in 1712 with a remarkable twist in Philippe Verheyen, who had duplicated Leeuwenhoek’s observations and had himself seen tiny wiggling bodies

in the sperm that he had seen neither in blood nor in bile. He nonetheless concluded that what were involved were inanimate particles stimulated by the movement of the “agitant spirits, which are called genital spirits and aura seminalis, and which, in my opinion, cannot be discovered even with a microscope.’ *?? In 1712, Ango was willing to see in the so-called animalculi only filamenta seminis exilia {insignificant seminal filaments], but as regards examination, he seems to have done no more than read Tauvry.>** In 1718, Mauquest de La Motte was still to consider animalculi as “ramose and branching particles” stimulated by spirits.*”? This would still be the opinion of Martin Schurig in 1720.3°° Except for Verheyen, whose mistake shows us how hard it was to carry out a proper observation of spermatozoa at that time, it seems apparent that none of these doctors had ever handled a microscope. Among the obstacles to be encountered by animalculism, the most serious seemed necessarily to be the ovist doctrine, to which Leeuwenhoek attributed in advance all the difficulties he would have in convincing people.*?” No

doubt his opinion was founded on the attitude of Nehemiah Grew, whose resistance to “vessels” was motivated by ovist convictions. In fact, if animal-

New Discoveries in Animal Reproduction 251

culism could not be reconciled with the preexistence of the embryo in the egg, it was not incompatible with ovism proper. This is what Garden demonstrated as early as 1691, maintaining that the embryo was in the sperm cell, but that this germ could not develop except inside an egg, and specifically in its cicatricula.>?* Garden based his argument on the most solid proofs of ovism: tubal pregnancies and the fact that a woman who has lost her ovaries could

not conceive. He set forth his ideas to Leeuwenhoek in a letter dated September 1693, to which Leeuwenhoek replied on February 28, 1694, through a letter to the Royal Society. The reply was categorical, and Garden's theory was rejected absolutely. Next to arguments of no great merit, there was one absolute assertion on which Leeuwenhoek was never to change his mind: the ovaries were “pure inventions— mera figmenta.” °°? One needed only to look in order to be convinced. Speaking with astonished scorn of Régnier de Graaf, who had been his patron, and of Swammerdam,*°° Leeuwenhoek was absolutely sure of himself. He was to remain so until his death, himself a vic-

tim of the theorizing mentality that he had denounced in others, but that took a special form in this observer of phenomena: refusal to accept facts that he had not verified himself, even though he had never devoted himself to a

coherent examination of the matter.*°! |

Leeuwenhoek would remain alone, however, in the belief that the animalculus settled in a spot on the womb ordained for that purpose. Garden won

out in the scientific world, and it was in the form of “ovo-vermism” that animalculism gained a following. For Hartsoeker, in 1694, the “worm” proceeded up through the horns into the ovary, penetrated the egg, and thus provoked its release.4°* Andry followed Hartsoeker and upbraided Leeuwenhoek for his stubborn rejection of eggs. He even specified that the egg had only one orifice, at the point where it had been attached to the ovary: the worm entered there and, once inside, stopped up the passageway, thus preventing another worm from entering. Unless, that is, one wished, along with a Paris doctor, to accept the existence of a valvule that the worm closed once it was in the egg.4°3 Geoffroy adopted Andry’s views in 1704,4°4 and was followed by Father Pierre Le Brun, the anonymous author of an account of a monstrous birth published in 1707.4% In 1708, Hermann Boerhaave thought that the encounter between the egg and the animalculus took place in the womb, and that the animalculus “inserts itself through already dilated pores in the thin membrane of the egg, now become glandulous.” 4°° Lecourt in 1712 was an “ovo-vermist, which allowed Ango to imagine ironically the worm climbing up into the ovary and examining all the eggs in order to find a ripe one

252 THE SCIENTISTS PHILOSOPHY in which to install itself.4°” Leibniz (1715) 4°® and James Keill (translated by Pierre Noguez in 1723) *°° were ovo-vermists as well, and Vallisneri was able to write in 1721 that no one had accepted Leeuwenhoek’s idea about the “uterine spot.” “1° Thus it was not the authority of ovism that the doctrine of animalculi ran up against but rather its own inherent difficulties. However, ovovermism brought in additional difficulties. There was a notable disproportion between the large size of the egg and the extreme tininess of the animalculus, as Bourguet was still to remind his readers in 1729. Moreover, Bourguet did not see how the animalculus could have the idea of guiding itself towards the

egg and penetrating it. Here we encounter again, in scientific form, the objection expressed by Ango in burlesque fashion.“ Finally, Bourguet did not understand how the animalculus could unite with the egg to the point of forming with it the ensemble that the embryo and its placenta represented.*” The animalculi themselves, however, created many problems. In the first place, there were so many of them. As early as his letter to Christopher Wren of January 23, 1683, Leeuwenhoek had to defend himself on this point, which he did, as he always would, by saying that trees, too, had many seeds that, in the end, served no purpose.*!3 The reply did not appear convincing. As early as 1696, Verduc found it impossible to understand the reason for such a great quantity of animalculi.“'* Dionis judged in 1698 that this meant “a lot of wasted seed.” 4!° This was also Lister’s opinion that year,*!® to which Leeuwenhoek replied on June 23, 1699, adding to the analogy with trees a more interesting argument founded on the great number of offspring produced by fish.*!” But that did not keep Tauvry from repeating the objection in 1700,4!8 and Ango faithfully followed Tauvry yet again.*!? Neither FrancescoMaria Nigrisoli in 17124? nor Bourguet in 1715 nor Johann-Wilhelm Pauli in

1716 could understand the utility of so prodigious a quantity of animalculi destined to perish, and Pauli deemed such wastefulness incompatible with divine wisdom. The argument drawn from plant seeds, which Leibniz used against Bourguet 4?! and Leeuwenhoek against Pauli, in a letter addressed in fact to Leibniz,*?? was founded on a questionable analogy and was decidedly not good enough. Vallisneri would point this out in 1721: under optimal circumstances, nearly all of a tree’s seed could develop. In the human species, in which there was generally only one egg, all the animalculi had necessarily to die, save one. The disproportion was too enormous and the absurdity too great, especially if one considered that fish, for an infinitely greater number of eggs, had no more animalculi than man. That could not possibly fit in with the perfect harmony one saw in nature.‘”? Vallisneri’s rejection was the revolt

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of reason against an implausible fact. As for counting in favor of the animalculi the fact that they allowed us to understand how the Dutch countess had been able to spawn 364 babies in one delivery, this was tantamount to attempting to explain an extravagant story by means of an absurd hypothesis.44 Andry claimed that one could also understand the phenomenon of late pregnancies: the animalculi might stay several weeks, nay, two or three months, before entering the egg. The high number of animalculi served precisely to make this occurrence rarer.*?* But Vallisneri considered that a pregnancy of thirteen months was about as believable as the Dutch countess’s 364 offspring, and he scoffed at Andry’s naiveté.4#° There was decidedly no way to justify the enormous number of animalculi. Hartmann would bring this up again in 1733,*?” and no one would be able to supply a satisfactory answer to a question that, in any case, did not seem to allow of one.4?® This question, made inevitable by the mentality of the time, carried theological implications as well, which Brunet brought up as early as 1698. “With this doctrine,” one accused “the sovereign Ruler of having carried out an infinite number of murders or created an infinite number of useless things by forming in miniature an infinite number of men destined never to see the light of day.” 47? An infinite number of murders, that is, if these animalculli were already men or at least human embryos, which faith itself prohibited Joseph Besse from believing, “for since they move, one would have to say that they are already ensouled, God being obliged to create the soul as soon as the body can exercise its function; now, our faith teaches us that God creates the soul of the human fetus only when it is in the mother’s womb.” #*° The Journal des Savants judged it necessary to note this argument, even while considering it to have little weight: “This author assumes, as one sees, what he is to prove: namely, that these little animals cannot move as they do without their being capable of exercising all the functions necessary for the suffusion of the soul. Which begs the question.” 431

This question, moreover, simply raised in theological terms the infinitely broader issue of the very nature of spermatic animalculi. Were they or were they not little men? Hartsoeker was convinced they were and did not hesitate to provide an illustration representing a human embryo hidden in the sperm cell, such as “we would perhaps see it . . . if one could see the little animal through the skin covering it.” The illustration showed a complete embryo with a very large head and knees drawn up to its forehead housed in the body of the tiny animal.*3? Hartsoeker was explicitly accepting the preexistence and encasement of the tiny creatures.4%* Régis was already aware of this

254 THE SCIENTISTS PHILOSOPHY theory in 1690, and Homberg had no doubt already accepted it.434 Francois de Plantade, a physician in Montpellier, had no qualms about proclaiming in 1699 that he had been able to observe the interior of a tiny animal, and that it indeed contained a complete embryo pretty much as Hartsoeker had imagined it.49> ‘This was a hoax, but one that enjoyed a certain success. Still, a system that required belief in the inevitable and useless massacre of thousands of embryos for a single birth gave rise to the theological difficulties indicated. Common sense rebelled against it. And then, commented Lister in 1698, how could we accept the idea of such agility in embryos? ** Finally, this notion had against it the authority of Leeuwenhoek. Leeuwenhoek’s thinking was not, however, very clear on this point. He seems to have been absolutely convinced that the animalculus contained a complete human embryo. In 1693, he expressed the hope of discovering “the body parts and the membranes of the fetus in this animalculus, to the point of being able to say: here is the head, here are the shoulders, and here are the thighs.” But he had not yet found an embryo large enough to permit it.497 In 1699, he no longer thought this observation possible, and this was one of the reasons that kept him from accepting the supposed discovery of Plantade. He nonetheless remained persuaded of the presence of the embryo in the animalculus: “The human fetus, at least in my opinion, is hidden, enclosed, in the animalculus of the male sperm; but that the human mind will one day be able to penetrate into this great hidden area, to the point where chance, or dissection methodically carried out on the animalculus, will reveal a whole man inside it, goes beyond my understanding, I willingly admit; and it will be hard to convince me that this can occur.” 48 A position such as this was quite remarkable in a man who was above all an observer, showing that it was difficult indeed to defend oneself against the temptation to “systematize” and against the mentality of the time. Lister’s objections made not a dent in

| Leeuwenhoek’s convictions. The analogy with the preformation of a plant in its seed, a preformation about which he had long been convinced,4*° seemed to him to remove all doubt, and if we could not imagine how so small a being could contain so many parts, we had to fault the weakness of our own minds and leave things to “the unfathomable depth of the Supreme Wisdom.” 4° If Leeuwenhoek accepted the preformation of the embryo in the animal-

, culus, he nonetheless refused to believe that the animalculi had existed since the creation of the world. After all, he had long since observed that side by side with the adult animalculi, others were being born and were growing.**! In 1716, he would still speak of these infant and adolescent animalculi.44? More-

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over, he had thought he could distinguish male from female animalculi.** The conclusion was therefore inevitable: the animalculi were begotten in the testicles, and “all of them, down to the very last, are engendered, through the course of time, from those that existed at the outset.” 444 This meant that the animalculi constituted a particular animal species, and that they reproduced like other animals.*4° They were not men, yet they contained men.** The intellectual predicament was manifest. Thus it is not surprising that Andry, in 1700, working hard to be faithful to Leeuwenhoek, asserted on the one hand that we must not imagine “the spermatic liquid of dogs containing little dogs, that of cocks little cocks, and that of humans little children,” and defended Leeuwenhoek against this accusation,**” while on the other hand he expatiated on the material possibility of an embryo being present in so tiny a worm “48 and ended by believing in a kind of infinite encasement of spermatozoa.*4?

The doctrine of worms that were worms and that became men encountered lively objections, the first of which were set forth by Lister in 1698. If the animalculi were born, grew, and reproduced, it was necessary to assume that as worms they possessed a development of their own that guided them from birth to the adult state. But the adult animalculus that became a man took on a second development, as a human embryo. The idea of a two-stage development, with an adult stage between the two, appeared utterly absurd to Lister.4°° In 1712, Verheyen judged “indecent the idea that a man could naturally produce an immense number of animals [not, of course, what Leeuwen-

hoek thought] . . . and that all men, except for Adam and Eve, are born of animals.” 4°! It was Vallisneri, however, who in 1721 undertook the most methodical critique. If the animalculi were true worms that became men, their

transformation was a metamorphosis like that of insects and must include the intermediate stages of nymph and chrysalis. However, these intermediate stages had never been observed. The general laws of nature, moreover, did not allow us to believe in the metamorphosis of a worm into a man. If one were going to claim, Vallisneri added, that this was a special case, I will reply that these metamorphoses had at one time their moment of glory, but today they have lost their credit with the best-informed moderns, since Malpighi in plants, Swammerdam in insects, and all the most renowned philosophers, in every living being, have discovered that birth and growth are nothing but a continuous development. . . . This is why in our case as well, there cannot exist, and one must not accept the notion of, a sudden transformation or metamorphosis of a worm into a man.452

256 THE SCIENTISTS PHILOSOPHY In other words, to believe that a worm could become a man was to believe

that a wasp could come from a caterpillar and to deny the fixity of species in order to return to the daydreams of Father Kircher. If the animalculus was

a worm, it could not become a man. If it was already a man, it was hard to understand why he should almost inevitably be condemned to death, or where he had come from. As Antoine Maitre-Jan put it in 1724, if the worms were men, they could reproduce only as worms; and one could not accept the idea that the worms were not produced progressively, for an animal could not contain at birth a sufficiently great number of them for the issue of an entire active lifetime. Maitre-Jan performed the calculation: a cock in possession at birth of 100 million animalculi would be sterile at the end of 70 days of sexual activity.4°3 And a moderately serious mind could not accept, along with Edmé Guyot, that the spermatic arteries produced eggs that hatched in the testicles in order to furnish animalculi, “with each worm emerging from its shell like a chick.” 4>4

It is clear that these difficulties, insurmountable within the mentality of the time, did great harm to the doctrine of generation through spermatic animalculi. After Leeuwenhoek’s death in 1723, animalculism vegetated, without hope of any new observation coming along to revitalize it. The only item generally accepted was the actual existence of these tiny living beings. As for the

purpose of their existence, it was discussed somewhat hopelessly. Lister, in 1709, thought that they were made to stimulate men to sex.*°? In 1721, Vallisneri rejected this idea and believed that the worms served to stir up the male sperm lest it solidify.4°* Bourguet in 1729 saw them as mere parasites, analogous to intestinal worms.**” This would also be the opinion of Pierre Lyonet in 1742.48 In 1745, Robert James's Medical Dictionary would consider them the product of the sperm’s putrefaction. Most scientists would no doubt have

subscribed to this definitive judgment: Leeuwenhoek’s theory was “utterly romantic, and incompatible with the behavior of Providence, such as one can observe it in all of nature's productions.” 4°? And there remained those who refused to believe in the very existence of animalculi, among whom the great Linnaeus was to be numbered.*©° In 1750, panspermia would no longer be anything but a subject for jokes, according to John Hill.4! Seventy years after

: their discovery, and despite the relative success that they had enjoyed in the early years of the century, spermatic animalculi still encountered an increasing general incredulity.

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II] Between 1670 and 1745, knowledge of the phenomena of generation made immense progress, the first since Galen. The naturalists, through their patient investigations, destroyed the myths of spontaneous and irregular generation, which had weighed so heavily on all attempts at serious explanation of ani-

mal reproduction. The prodigious development of anatomy permitted the discovery of the functioning of female organs in viviparous animals. The role of the ovaries was finally clarified, the existence of the yellow bodies and the movement of the tubes were established. These were all definitive acquisitions. The extraordinary Leeuwenhoek, “inventor” of sanguinous globules, bacteria, and rotifera, revealed to the scientific world the unimaginable existence of the sperm cells. When one thinks of science in 1650, of the adherents of the theory of “faculties” and the romancers of mechanism, one can only admire an upheaval that was far more than mere progress: it was a true break with the past. Modern science was truly born at that time, or at least its foundations were set in place, so that the following periods did not need to start all over again. And yet the scientists at the end of this period seem to have been quite far from believing themselves in possession of certainties. The great effervescence of discovery that had begun about 1660 ended after 1725. And the doctrines founded on the results of recent investigations were still terribly fragile. Partisans of ovism gave up looking at the eggs of viviparous animals and declared them invisible, which could hardly be taken as a proof of their existence. Believers in spermatic animalculi maintained, also without definitive proof, an

opinion that ran counter to common sense. And not only were the newly discovered facts not sufficiently established to gain universal acceptance, but, worse still, they could not answer all the questions being asked, questions to which they were being summoned to bring immediate solutions. Debate between the two sides dragged on in desultory fashion. For the scientific world was slowly turning away from these insoluble questions. To be sure, many experiments remained to be done, ones that were not

beyond the scope of the science of the time. But minds were being drawn towards other problems. Anatomy no longer aroused the same enthusiasm as in the heyday of universal mechanism. Enthusiasm was now being awakened

by the enigmas and marvels of the insect world. The best anatomists were fascinated by teratisms. Moreover, it is easy to understand why the mechanisms of generation no longer excited the curiosity of biologists. They had

258 THE SCIENTISTS PHILOSOPHY been purely and simply eliminated. The theory of preexistent germs had removed all motivation for infinitely delicate research. This is the theory that we must examine now. But before commencing to study it, we need carefully to note the fragility, around 1745, of the two great theories of generation, which alone will permit us to understand the reaction that subsequently set in.

The Preexistence of Germs

THE THEORY of the preexistence of germs, which invaded biological thought at the end of the seventeenth century, offers the historian an astonishing spectacle, in terms not only of its content but also of the rapidity, extent, and persistence of its success—and this despite the insupportable difficulties it quickly generated. Conceived around 1660, it spanned the entire eighteenth century and died a slow death only in the nineteenth. Only its perfect adaptation to a singularly long-lived scientific mentality, whose birth and evolution the preceding chapters have explored, explains this astonishing turn of events. Before we look at the history of this doctrine, a confusion that has at times

led historians astray must be dispelled and a distinction made between the preformation of the germ and its preexistence. We have seen how the theory of the preformation of germs developed in the early years of the seventeenth century among physicians and thinkers such as Fortunio Liceti, Emilio Parisano, and Giuseppe degli Aromatari. It was framed as a response to the insoluble problems raised by the ensoulment of the seed. According to this theory, true generation, the actual formation of the living being, occurred in the body and thanks to the soul of the male parent. The product of this generation, the seed for the plant or the semen for the animal, thus contained entirely formed, or preformed, so to speak, the life that was to issue from it. Embryonic development was thus no longer formation but simply enlargement of already existent components. It was this theory, which could claim the support of Hippocrates and answered the questions raised by science in 1625, that Harvey fought against in proposing epigenesis. The enthusiasm of Descartes and his contemporaries for mechanism and the banishing of bio-

260 THE SCIENTISTS’ PHILOSOPHY , logical “souls,” along with their problems, seemed to have stripped the theory

of preformation of all its raison d’étre, at least in the eyes of the most advanced scientists, and epigenesis reigned triumphant in 1650. In fact, it had never been seriously challenged: traditional epigenesis gave way to mechanical epigenesis, and preformation could then be seen as a blind alley. The doctrine of the preexistence of germs, which began to circulate start-

ing in about 1670, partially coincided with that of preformation. Like the latter, it afhrmed that the living being was not formed from a nearly homogeneous matter, whether seed or semen, but rather that it already existed completely formed in this grain or semen, and that its “development” — this is the word generally used—was merely an enlargement of its components. But the doctrine of preexistence added that the germ contained in the semen or the seed was not produced by the male progenitor: it had been created by God himself at the beginning of the world and had been preserved since then until the moment of its “development.” The adult who seemed to have begotten it or brought it into the world had really served merely as a shelter or foster parent. This theory was essentially a response to problems analogous to those that preformation had sought to resolve. But its implications (which were immediately perceived) were infinitely broader, and the scientific form that it took on was to have much greater importance in the history of ideas. The solution it proposed bears admirable witness to the mentality of the time. The distinction between preformation and preexistence was not, however, always clear to the scientists of the late seventeenth century. In preexistence, many biologists at first merely saw preformation. Gradually, the two positions were clarified, the doctrines became rivals, and preexistence won out. And if

, a confusion in terms still persists at times, it is generally easy to avoid falling into it. I

The Origins of the Doctrine of Preexistent Germs

If the theory of preexisting germs owed its essential characteristics to the scientific mentality of the period that gave rise to it, it was in reality merely a response to an extremely old problem, which the decline of Aristotelianism in the sixteenth century had made urgent: that of the origin of forms, a subject already raised above, but one to which we must now return. Everything natural, and especially every living being, needless to say possesses matter

The Preexistence of Germs 261

and form. There was no problem with the origin of matter, but the difhculties raised by form were serious. True, at least in part, to Aristotle, Saint Thomas Aquinas considered that the form of a being appeared when that being, having existed potentially in matter, was realized in actuality.’ The famous Scholastic formula “Formae educuntur e potentia materiae” [Forms are educed from the potentiality of matter] has to be understood in this sense.’ For Aquinas, “the form does not preexist as a separate being .. . , it is born in the belly and womb of matter.”* Moreover, he took issue very explicitly with those who maintained the “hidden preexistence of forms [/atitatio formarum],” or their “creation by a separate agent.’ 4 Aquinas has been accused of Averroéism,’ and his doctrine on the educ-

tion of forms is surely not unrelated to that imputation. What is still more certain is that it was judged heretical in the sixteenth century, at a time when Aristotelianism in its entirety came close to being included in the solemn condemnation of the followers of Averroés and Alexander of Aphrodisias by the Lateran Council in 1513. For the thinkers of this period, the latent impiety of Aristotelianism found its natural antidote in Platonic thought, under whose burgeoning influence Aristotelian commentators came to understand form as a completely independent factor from without (thurathen) informing matter.° This is what emerges from Jean Fernel’s long discussion of the origin of forms.’ After quickly rejecting the opinions of Alexander and Averroés, which tended to consider the form of a complex being as the sum of the qualities

of its elements,’ Fernel attempts to interpret the Scholastic formula on the eduction of forms. The first and most natural interpretation that arises resembles that of Aquinas: a thing that is transformed through passage from potentiality to actuality — for example, an embryo that becomes an animal — acquires its form at the moment when that transformation is finished. Thus,

“the form of everything . . . is born and truly emerges from preparation and potentiality.”® But Fernel firmly rejects this interpretation. The form is either in the embryo or it is not. If it is not, no preparation or potentiality can bring it into existence.’® So rigid a way of conceiving, radically separating potentiality from actuality, testifies to an obvious lack of understanding with respect to the dynamic aspect of Aristotelian thought. But neither does Fernel allow, despite the authority of Themistius, that form might be in actuality in the seed, at first idle and then active." This is easy to understand if we recall the inextricable difficulties to which those who accepted this idea became exposed. Then Fernel has only one way of explaining the origin of forms: they must descend from heaven.” Although grounded

262 THE SCIENTISTS PHILOSOPHY in Aristotle's well-known formula “Homo generat hominem, atque sol,”* it | is all too clear that this solution is not Aristotelian, despite the miracles of ingenuity that Fernel performs to bring it into agreement with words of the master that formally contradict it.’ The Platonic inspiration is obvious: the forms that descend into nature emanate from “the eternal ideas or forms of things” that are in heaven." It is rather amusing to see Fernel then applaud the admirable agreement on this point that reigns between Plato and Aristotle.’ The solution proposed by Fernel was too strongly imprinted with the seal of his century to be acceptable in the following age.’ The seventeenth cen-

tury was hardly inclined to bring forms down from a heaven that had just lost all divine character. Moreover, the notion of form, emptied at last of its Aristotelian content, had become unintelligible to the new thinkers. An increasingly rigorous distinction was being established between a purely passive matter and the soul, which rendered absurd the old Scholastic formula concerning the eduction of forms.’” Finally, and above all, it was nature as a whole that, by becoming a complex of mechanisms, had lost all spontaneity

and become pure passivity in the hands of God, the God who had created it and was now content with simply maintaining its existence and motion. In the last analysis, nothing appeared in nature that did not come from the original creation of all things.

As we saw in Chapter 3, this fundamental conviction motivated the thought of Daniel Sennert.’® The true generation of a living creation was the

formation of the seed, and the soul that animated this seed emanated from the soul of the father. Thus, every soul, which meant every life and every living being, was merely a link in an uninterrupted chain extending to the creation of the first living being of each species. The preformation of the germ, such as we have found it more or less clearly expressed in Fortunio Liceti, Emilio Parisano, and Giuseppe degli Aromatari, responded to a similar preoccupation. These scientists lacked Sennert’s intellectual rigor, or did not dare pursue their reasoning to its ultimate consequences. But by acknowledg-

ing that the embryo was already formed in the seed, that is, in the body of the male parent itself, they closed the line of filiation so tightly that there was no place in generation for an external intervention from any source whatever.

Here, too, the generations had followed one another in an unbroken chain

since the beginning of time. | A doctrine such as this ran the risk of producing unfortunate theologi* “Man begets man, along with the sun.” — Tr.

The Preexistence of Germs 263

cal consequences; above all, however, it ran into the problem of spontaneous generation. There, preformation of any sort was no longer possible. We have seen that Liceti, more Aristotelian than consistent with himself in this case, simply returned to the eduction of forms, and was reproached for it by Sennert. Insisting on the necessity of a soul, Sennert accepted spontaneous generation only from living or dead matter. But was it not established that cer-

tain animals could be born from clay? And here was where we must bring in the chemists. For them, the generation of living beings was merely a particular instance of the generation of all things. Metals were begotten as well. And chemical thought, nourished by the Bible and by a Neoplatonism tinged with Kabbalism, was hardly disposed to follow the paths of Averroés by grant-

ing matter the power to organize itself. For Jean-Baptiste van Helmont, the primary element was water, which was the leaven, or “seminal principle,” responsible for the generation of things. It, too, had been created at the beginning of time and “scattered throughout the lands of its monarchies” to assure the formation of beings unto the end of time. Sennert himself seems to have adopted an analogous theory for the generation of metals, for which he could not employ the notion of a soul.’? The astrologer Jean-Baptiste Morin, in 1651, attributed the generation of bodies to an immaterial spirit created by God at the beginning of the world.”° For these authors, matter swarmed with spiritual beings, which, created by God on the first day, start at the proper moment to organize a certain quantity of matter to make a mineral, a plant, or an animal out of it according to the plan foreseen by the Creator. By attributing the same origin and the same role to the human soul, the Cambridge Platonist Henry More joined hands with this current of thought. Thus, in the mid seventeenth century, two spiritualist interpretations of generation confronted—or complemented— each other, the one founded on an uninterrupted series of souls begotten one from another since Creation, the other on the existence of spiritual beings that were isolated and immersed in matter since Creation. In considering matter to be absolutely passive and attributing the origin of all things to the Creator, both interpretations shared in the spirit of their time. But both had the serious defect of having spiritual entities act upon matter, something that the spirit of the time tended to reject. Thus it is not surprising to find both of them making an appearance in materialist form. It seems probable that Nathaniel Highmore, who like Sennert accepted the emanation of souls, but who thought the soul was composed of atoms, conceived of this emanation in terms of the transmission of the motion of atoms.

264 THE SCIENTISTS PHILOSOPHY However, his thought on this point is not clear. That of Gassendi, on the other hand, is perfectly clear. In the case of normal generation, because the animal soul was composed of atoms, the soul of the seed emanated from the male parent, and this emanation was reducible to a communication of motion. The transmission of hereditary qualities functioned in the same way. Gassendi’s

theory is to be seen, therefore, as a materialist translation of Sennert’s. As for spontaneous generation, it was explained by the presence in the heart of matter either of material principles endowed with a certain movement since Creation—the material equivalents of Helmont’s ferments—or quite simply by seeds created at the beginning of the world—the preexistent germs. The doctrine of the emanation of souls conceived as a communication of movement presented serious drawbacks. Insofar as it left to the soul the re, sponsibility for organizing the seed and the embryo, it belonged to an already outdated mentality. The notion of a material soul was ambiguous and risked impiety. Gassendi’s lesson was not, for all that, wasted. Disencumbered of any allusion to soul, it was capable of being adapted to Cartesian mechanism. Owing to his confidence in the infallibility of the laws of motion, Descartes had left the responsibility for organizing and perpetuating the world to those laws, but his disciples felt the need to provide a more solid basis for the sur-

, vival of species, and as we shall see, they invoked the communication of specific movement for this purpose. However, what was retained above all was the explanation of spontaneous generation. It corresponded, in fact, to one of the deepest tendencies of the period, which was to take everything away from nature in order to give everything to God. Creation had to be a mechanism emanating in its entirety from the hands of the Creator, absolutely complete and perfectly established. Even

though the laws of motion were merely the exact expression of the divine will, Descartes had still given too much to nature by attributing the power to organize the world to the laws of motion. As we have seen, Robert Boyle made no distinction between the “Cartesian laws of motion” and the “chance encounter of atoms, according to Epicurus.” Both doctrines took something away from the universality of the creative act. Now, everything came from God, and nothing existed that was not drawn from nothingness on the day of

| Creation. That is, things were not produced “virtually” or “potentially” but only “in reality” and “in actuality.” The seventeenth-century mind rejected the notions of virtuality and potentiality, which it considered as incomprehensible degrees between being and nonbeing. The Bible told us how God created each star, each plant, and each animal, and the time was past when it

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had been licit to interpret Genesis in symbolic fashion. God shaped each of the beings that we saw one by one, so to speak, with his sovereign hand. For all the writers mentioned here, every form was definitively set by the Seventh Day. The universe could only remain what it was, with God’s aid. The appearance of a form was inconceivable, whether one claimed to attribute it to the

potentiality of matter or the laws of motion. The theory of preexistent germs was merely a means of bringing back to this unique, definitive, and completed Creation all the living beings that had since been born, or were to be born, and seemed to have escaped it. Through the same intellectual motivation that obliged him to reject Cartesian cosmogony and the formative power of the laws of motion, Boyle had to accept that God “did more particularly contrive some portions of that matter into seminal rudiments or principles, lodged in convenient receptacles (and as it were wombs) and others in the bodies of plants and animals.” ”?

In this position, the opposite of Thomist doctrine, it-is easy to recognize the influence of Augustinian thought. Now, it is very clear that the entire movement of ideas just described, from Helmont’s ferments to Boyle’s “seminal principles,” was merely a restatement, conscious or not, of the Augustinian theory of seminal reasons.”* In order to explain how— God having created everything — new beings were still being produced within nature, Au-

gustine had recourse to this notion of Stoic origin, which he had perhaps found in Plotinus.** He conceived of these germs as endowed with a vaporous nature, but possessing at the same time a principle of activity that would permit them to develop at the right moment. But considering them as purely formal beings, the chemists (especially Helmont) obviously distorted Augustines thought, and by considering them as purely material beings, Boyle and his successors were to distort it no less. Beyond these distortions required by the difference in intellectual currents, it is especially important to note the perfect adaptation to the seventeenth-century mentality of a doctrine that, according to Etienne Gilson’s formulation, “eliminates . . . all hint of any creative efficacy whatsoever in the activity of man and other created beings.” ?° Boyle still remained a mechanist and conceived of his seminal principles in the manner of Gassendi, as aggregates of atoms animated with a certain motion and able to communicate that motion to the matter that they were charged with organizing.*° Therefore he continued to consider the formation of living beings epigenetically, as is evident in his description of the development of a chick’s embryo.’” This perhaps explains why he still accepted the notion that putrefaction, imparting a local motion to particles of matter,

266 THE SCIENTISTS PHILOSOPHY allowed them to gather together in such fashion as to form insects.”® But this confidence in the creative mechanisms of life was not shared by everyone. _ Dealing with spontaneous generation, and still on the subject of the origin of forms, Jean-Baptiste Duhamel in 1663 assumed the existence of invisible seeds scattered throughout the universe. He grounded his notion in the authority of Plato and Saint Augustine, as well as in that of the chemists, “who believe that the hidden seeds of things lurk in the depths of the elements.” ”? Unless one either accepted this explanation in terms of “seeds . . . created at the very origin of the world” that were “preserved in the elements” or, con-

versely, thought that life was born “from the chance encounter of external causes, all one could do was to believe that “insects and imperfect animals... are begotten by animals of the same species.” °° Could one speak of “spontaneous’ generation in either case? Father Athanasius Kircher (1664) thought

that God put a “spermatic force, a “salino-sulphureo-mercurial spirit” in matter to function as the “universal seed of things.” Thus he could afhirm that “God created everything at the same time.” *' This is precisely the formula Augustine borrowed from Ecclesiasticus: “Deus creavit omnia simul.” *”

In 1668, just when he was presenting the results of his experiments, which tended to discredit spontaneous generation, Francesco Redi expounded the two possible explanations of the phenomenon, and they were those we have found in Gassendi: aggregates of atoms in motion or seeds scattered throughout matter. Thanks to these seeds, Redi wrote, “one can understand what one reads in Holy Writ, that God created all things together.” Harvey, he went on to say, had accepted this explanation.* Such was the state of the age-long debate on the origin of forms on the eve of Jan Swammerdam’s discoveries. The word form itself had lost its meaning, and it is understandable that Pierre Bayle should have seen in the substantial forms of the Scholastics the mere equivalent of the Virtues, Principles, and other mediating Intelligences.** Aristotle and Aquinas had gradually given way to Plato, Augustine, and mechanism. Preexistent germs had become the only possible explanation for spontaneous generation. It required only a few observations for them to be able to lay claim, backed by the spirit of the age, to being the sole possible explanation for all generation of living beings.

The Preexistence of Germs 267 IT

The Formulation of the Doctrine (1669-1680)

If we are to believe Claude Perrault, he was the one who first proposed, around 1668, the theory of the preexistence of germs.*’ Nonetheless, the first work in which it was formally set forth was Swammerdam’s Historia insectorum generalis, ofte Algemeene Verhandelung van de Bloedeloose Dierkens,

which appeared in Dutch in Utrecht in 1669.°° Examining pupae and larvae, Swammerdam disagreed with Harvey and concluded that insects did not undergo metamorphosis. “The pupa is not an egg... , it is the very animal.” *” Upon removal of the external skin of a caterpillar, “one clearly sees the fully formed butterfly.” 28 Now, “all the works of the Creator are founded on the. same laws.” 3° We could therefore affirm “that no generation in all of nature occurs by accident, but by propagation and by an enlargement of parts.” *°

The advantages of this idea were at the same time scientific and theological: “Now we can easily understand how a man without arms and legs can nonetheless beget a whole offspring.” But, “still better, one can understand in this way how Levi, while still in his father’s loins, paid the tithe before being born.” 4! With one stroke, Swammerdam asserted the preexistence and the encasement of germs, although he did not possess the term nor give the idea its full clarity. These pages from the Algemeene Verhandelung were repeated in Latin in the Miraculum naturae of 1672. Swammerdam added as a clari-

fication that the preexistent germ was in the egg, that all human eggs had existed in Eve, and that “once the eggs were used up, it would be the end of

the human race.’ 4? |

Although apparently unknown in France,*? Swammerdam’s Algemeene Ver-

handelung was noticed by Philosophical Transactions, which highlighted the new idea.*4# The concept was still only the product of a perhaps hasty generalization when it was suddenly confirmed by an observation by Marcello Malpighi that would long remain famous. In a letter to the Royal Society _ dated February 1, 1672, published in London towards the middle of the same year,*> Malpighi reported that while examining a hen’s egg that had been fertilized but not yet incubated under a microscope, he had discovered in the cicatricula the essential elements of the embryo. “It is therefore fitting to admit,” he concluded, “that the primitive filaments — stamina—of the chick preexist in the egg, and that they have an origin to be sought further back, in a fashion that bears some resemblance with that of the eggs of plants.”*6 __

268 THE SCIENTISTS PHILOSOPHY The importance that Malpighi assigned to analogy is well known. Still, he was not asserting the preexistence of the germ, properly speaking, but only its preformation. This preformation should itself have seemed dubious to him, for in examining the cicatricula of an unfertilized egg, he had found it smaller and possessing only a “spherical and white, or ashen, body, similar to a fleshy mole.” The interior of this mass had seemed homogeneous to him.*” Nonetheless, he accepted preformation, thinking that fertilization caused an invisible germ to appear. His contemporaries went further still, turning this observation into conclusive proof of the germ’s preexistence. Reviewing the letter from Malpighi, Philosophical Transactions felt it important to point out to the public that Dr. Croone, a member of the Royal Society, had made the same observation, and had presented it to that body on March 14, 1671.*8 Such a coincidence at least demonstrates that the idea of preformation, or of preexistence, was in the air. In any case, it was spreading fast. Juste Schrader pointed out in 1674 that Malpighi’s observations merely confirmed a theory put forward by Giuseppe degli Aromatari,*? which was true; and from that point on, it has become customary to cite degli Aromatari as the precursor of the preexistence theory, which is less true. It was possibly in the same year, 1674, that Hartsoeker, if we are to take him at his word, revealed his discovery of sperm cells and his conviction that each spermatic animalculus contained a fully formed embryo to Father Nicolas Malebranche.*° We have seen that the facts are far from cer-

tain. On the other hand, what is sure is that 1674 saw the appearance of the first volume of Malebranche’s De la recherche de la vérité. In the second chapter of book 1, while dealing with the errors of our vision, the philosopher sets

forth with perfect clarity the theory of preexistent and encased germs. He took as his evidence a personal observation, that of the germ of a tulip bulb in which he discovered the entire tulip plant already fully formed. Moving from there to all plants, he thought it safe to “say with some certainty that all trees exist in miniature in the germ of their seed.” But the trees thus enclosed already contained their own seeds, “which all may enclose inside them new trees, and new seeds of trees,” and so on, “to infinity.” A single apple seed contained “apple trees, apples, and the seeds of apple trees for endless, or nearly endless, centuries, in the proportion of a full-grown apple tree to an apple tree in its seed.” This idea could “seem foolish and bizarre only to those who measure the wonders of God’s infinite power with the ideas of the senses and their imagination.” *! Malebranche had already alerted us to the fact that we possessed “conclusive mathematical demonstrations of the divisibility of

The Preexistence of Germs 269

matter to infinity; and that suffices to convince us that there can be smaller and smaller animals to infinity, even though our imagination is aghast at the thought.” *? Let us, then, accept the existence of our apple trees encased to infinity, and let us judge that nature did “no more than develop these little trees, by giving a perceptible enlargement to the one that has emerged from the seed, and imperceptible, but perfectly real enlargement, and proportionate to their size, to those one conceives as being inside their seeds: for it 1s beyond doubt that there are bodies small enough to be inserted between the fibers of those trees that one conceives as being inside their seeds, in order to serve as nourishment for them.” >? From there, Malebranche moved on to animals. Citing the observations by Malpighi and Swammerdam,™ he concluded “that all the bodies of men and animals to be born until the fulfillment of time were perhaps produced at the creation of the world; what I mean is that the females of the first animals were perhaps created containing all those of the same species that the animals have since engendered, and that are to be engendered in the continuation of time.’ ”° It is not the aim here to analyze the role of the preexistence theory in Malebranche’s philosophy.*® Still, it is evident that this philosophy mustered all the tendencies that necessarily led to the preexistence of germs. Malebranche did not “borrow” the theory of seminal reasons from Saint Augustine, by whom

he was deeply influenced. He “rediscovered” it, so to speak, on his own, through his desire to remove all autonomy from the created world,”’ and by his profound mistrust of mechanism, which he judged to be as incapable of having organized the world as of forming a living being. For Malebranche, as for Isaac Barrow, Robert Boyle,’® and a great number of scientists whom we have already encountered, and whom we shall meet with again, mechanical principles were brought into the universe only after the creative act that had organized everything and preordained everything until the end of time.” In this way, Malebranche, like the others, was able to find in this universe a finality that Descartes could not see in it. For him, as for Barrow, Boyle, and the others, motion could extend an animal’s parts, but it could not form them, and Descartes had gone astray in writing the Traité de la formation du

foetus. “This philosopher’s outline can help us understand how the laws of : motion may be sufficient for making the parts of an animal gradually grow. But that these laws could form them and bind them together is something that no one will ever be able to show.” © Powerless physics gave way to divine Providence, and its powerlessness lay precisely in the fact that the world’s complexity was infinite, in the image of God’s wisdom. Malebranche’s phi-

270 THE SCIENTISTS PHILOSOPHY | losophy sheds clear light on a deeply embedded movement of thought, which

| was resolutely anti-Cartesian, and of which the theory of preexistent germs was a particularly noteworthy aspect. But at the same time, Malebranche gave this theory its clearest formulation, its most exact experimental proofs, and its most convincing rational arguments. Perhaps, indeed, without having intended to, he gave the word germ its unique meaning, even though he used it in its traditional sense (the active part of the seed or the egg). The word was to become current because it unambiguously designated something that no one had had any idea of before Swammerdam: the complete body of an animal, reduced to infinitesimal dimensions, purely material, and entirely inert. However that may be, Malebranche’s authority was continually brought to

bear thereafter, and his arguments on the weakness of our senses and our imagination, and on the divisibility of matter, were constantly picked up. This phenomenon finds its explanation in both the immense prestige of the philosopher and the perfect fit between his thought and the thought of his time. It is not known whether Guillaume de Houppeville had read Malebranche by 1675. But he had read Swammerdam and Malpighi, or at least he knew the results of their observations. He knew that the egg was “a small version of the animal, since with a microscope one sees already formed insects in eggs; I have seen small snakes in them, and Malpighi has seen a chick in the egg, even before incubation.” *' Houppeville had also read Saint Augustine. He refers at length to De Genesi ad litteram and marvels at finding so modern a definition of the egg “at a time when almost all scientists were biased in favor of generation through putrefaction.” ®* Similarly, he gloats in triumph over an anonymous opponent who had cited Saint Basil.°? In fact, it was impossible to set the two doctors and the two citations against each other except by distorting the quotation from Basil in an Aristotelian direction. Could the Académie have been excited by Malebranche’s assertions? In any case, on November 17, 1677, Edme Mariotte showed it a tulip bulb in which one could make out in the germ leaves, flower, and stamens, exactly as the Oratorian [Malebranche] had described them. A few months later, Denis Dodart performed the same demonstration on a narcissus bulb brought from the Cape of Good Hope and on a germ of wheat in which the blade was already visible.64 The secretary of the Académie, J.-B. Duhamel, was converted — probably with no great difficulty—to ovism and Malpighian preformation.® We have seen that in this same year of 1678, Leeuwenhoek, announcing the discovery of animalculi to the Royal Society, envisaged a preformation of the embryo, not in the animalculus but in the thick portion of the semen, while

The Preexistence of Germs 271

Nehemiah Grew rejected this idea, being already convinced of preformation in the egg. Indeed, starting in 1672, preformation or preexistence were in practice confused with ovism: Malpighi, Schrader, Malebranche, Houppeville, and Duhamel all failed to separate the two doctrines. For the convinced partisans of preexistence, it was therefore quite natural to imagine that germs were encased inside one another: each female contained in her ovaries eggs enclosing other females with their ovaries and their eggs, and so on. This way of seeing things was, of course, supported by the analogy with vegetables. Claude Perrault, whose treatise De la méchanique des animaux appeared in 1680,°° presented a different theory. This original work, combined with thought processes seemingly uninfluenced by the authors we have just examined, and relating to problems already outdated in 1680, suggests that Perrault was indeed, as he claimed, one of the first to conceive of the preexistence of germs, or at least that he arrived at this idea entirely through his own reflection.®’” For his thought was first of all critical: critical of the “formative faculty,” which he would take up again in 1688,°° even though everyone knew in 1680 “how empty and insubstantial the philosophers’ notion of this faculty has been”;® critical of an epigenesis that supposedly transformed a homogeneous seed into an animal, for the spirit “that one customarily proposes as the artisan of the formation is merely the most subtle part of the homogeneous matter: and this spirit, however subtle, is quite far from any capacity to carry out a production that it is impossible to attribute to anything except a truly intelligent cause.” As for charging the soul with this formation, that too was impossible. The soul left the body “as soon as the organs have some considerable incapacity”; it could not, therefore, reside in the body “without there being the organs required for its operations, and it is quite enough

that the soul be subtle enough to govern the body given it fully formed, in a manner suitable for its operations.” ”° What was left, then, was mechanism and recourse, pure and simple, to the laws of motion. Perrault really conceived of the living body as a machine, and his treatise studies “the mechanics of animals.” But mechanism had its limits for him, which were the very limits of nature. It should not be surprising that one gets nowhere trying to explain the formation of an animal through “the fortuitous encounter of materials diversely disposed to receive different shapes through the rarefaction, condensation, exsiccation, and coagulation of some, and through the ductility of others.”’! If the human mind could not find natural causes for the production of living beings, it was because nature herself could not provide any:

272 THE SCIENTISTS PHILOSOPHY I do not know if one can understand how works of this quality can be the effect of ordinary forces of nature: we must at least acknowledge that all the forms of industry in her operations are of a different kind, and farther below what is admirable in the formation of living bodies than the works we are capable of are below those of nature when we attempt to imitate them: the power that nature possesses to complete through growth, and to preserve through nourishment, what has been formed by creation in the bodies that must have life, and the faculty of using organs that are already made, being the only thing that one can imagine proportionate to her powers: for I believe, in the end, that it is hardly more inconceivable (if the expression may be permitted) that the world was able to shape itself out of the matter of chaos than that an ant could create its kind from the homogeneous substance of the seed of which people believe it is begotten.”?

It is not, then, mechanism proper that was at issue, it was rather nature itself, which was powerless to form an animal. But it amounted to the same thing, since it was understood that nature was entirely mechanical. On the

other hand, God’s power to create, and to give what He draws from nothingness the form of an animal whose perfection and nobility are as exalted above the form of other corporeal beings as the latter are above nothingness, is something we have no difficulty at all in conceiving, since there is nothing so easy as attributing to a power and a wisdom without limits works whose artistry possesses infinite wonders.’?

We had, then, to attribute directly to God the immediate creation of all living beings. This was Perrault’s “hypothesis,” according to which God simultaneously, on the one hand, created simple bodies, that is, the elements, and, on the other, “bodies capable of having life, provided with all the organs

necessary for their functions, but so tiny that it is impossible for them to exercise any. .. . Mixed in with these inanimate bodies, they await the occasion to encounter a substance subtle enough and properly set up to penetrate into the narrow conduits of their little organs and make them fit to receive the nourishment that will enable them to acquire a suitable size: and then what is called generation happens to them.” 4 The advantages of this hypothesis are apparent in the case of spontaneous generation, “since wherever there occurs a fermentation capable of producing a substance subtle enough to penetrate the infinitely tiny pores of organized corpuscles, generation takes place.”’’ The annual growth of plants, “which must be considered a repetitive generation of yearly occurrence . . . is also easily explained with the same hypothesis”: the sap or the branches contain “an infinite number” of corpuscles, which are so many complete plants, and that expand when penetrated by “the most subtle part of the sap,” except-

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_ing the roots, of course, which could expand only underground.’ However, roots would develop if a branch was layered in the earth. Finally, the sexual generation of animals was scarcely more difficult to understand. The “agglomeration of particles or little seeds . . . called eggs in reference to birds, but that are found analogically in all things that engender,” contained enclosed in one or several membranes a homogeneous liquid substance “which is the fermentation matter.”’’” The fermentation itself was activated by a subtle fluid provided by the male, which received “its final perfection” from “the action of the imagination.” “And this is the function of the different forms of mad-

ness that sexual excitement inspires in most animals, and that must not be considered useless, any more than the unfolding and the festive appearance of roses.”’* This male seed, causing the liquid substance of the egg to ferment, gave it the “subtlety needed for the penetration and development of the corpuscle.” At that point, “generation cannot but occur, because since the corpuscles exist in an almost infinite quantity of all kinds and all species in the world, it would be hard indeed not to encounter one or another in the homogeneous substance of the seed, or brought in . . . with the blood of the animal.” ”°

In its emphasis on spontaneous generation and its purely analogical conception of viviparous eggs, this system really seems to date from 1668 rather than 1680. Only the passage in which Perrault alludes, like Malebranche, to the infinite divisibility of matter, and especially to “the extreme smallness of animals actually living in fluids that appear very pure and simple,” ®° can be dated later than 1677 and Leeuwenhoek’s observations. The passage refutes, in any case, an objection that was much stronger when leveled against the encasement of germs than against panspermia. The confidence in mechanism that Perrault preserved remained considerable, since he granted “fermentation’ the power to render a homogeneous substance capable of penetrating a “little body,” and apparently only one belonging to the species in question. This was doubtless the reason he brought in the “action of the imagination,” the guardian of heredity. The animal was a machine, but it could not live without a soul: I would clarify that by “animal” I understand a being that has feeling and that is capable of exercising life functions through a principle called soul; that the soul uses the body’s organs, which are true machines, by virtue of its being the principal cause of the action of each of the machine’s parts; and that although the placement that these parts have with respect to one another does scarcely anything else through the soul’s mediation than what it does in pure machines, the entire machine nonetheless

274 THE SCIENTISTS’ PHILOSOPHY needs to be activated and guided by the soul in the same way as an organ, which, although capable of rendering different sounds through the placement of the parts of which it is composed, nonetheless never does so except through the guidance of the organist.®?

Nature could not live through itself any more than it could organize itself, and in this sense Perrault’s animism perfectly fitted his hypothesis of preexistent germs. It was as ridiculous and even blameworthy to want to “seek the inexplicable causes of the first formation of the world” as to claim to “find plausible and intelligible reasons for the formation of man, whom one can consider to have been called a little world as much because of the incomprehensible manner of his formation as because of the other kinships he has with the universal world,” 7 or to believe in the end “that one must seek no other principle for the activities of the internal senses of animals than the one that activates inanimate bodies.” *° To all those who asked these questions, nature would make no response, for nature had no response. One might possibly object that “to assume in this fashion things to be what they are, in place of explaining how they have become what they are, is a bit too easy a philosophy.” But was there a better one, when all the systems proposed had to be rejected “by virtue of their being too difficult to understand?” §* Let us be content, then, with what we could know: God had not wished “to hide all the wisdom he has employed” in the mechanism of animals.*° But the formation of the mechanism, like the mechanism of the universe, went beyond

the strength of our understanding, because it went beyond the strength of nature. Here we were up against God's mystery. Here we are, then, very far from Descartes, in Boyle’s line of descent, and even in many respects that of the chemists.*° But above all, and once again, we find ourselves in the tradition of Saint Augustine. It is hard to speak of direct influence, even though such influence is made highly plausible by what we know of Perrault’s intellectual milieu.®” Be that as it may, Perrault was peculiarly close to Augustine in the idea he held of the relations between nature and God; he was even closer to him than the other scientists we have studied, both in that his theory of panspermia is more faithful to the idea of seminal reasons scattered in the elements and in that his animism reproduces Augustine’s.** In any case, it is essential to acknowledge the role of Christian and

Augustinian thought in the birth of a theory of preexistent germs. Without it, we could not possibly understand the extraordinary reception given the observations of Swammerdam and Malpighi, the latter of whom, at least, was exploited more than was reasonable. No doubt Augustinian thought was ad-

, The Preexistence of Germs 275 mirably adapted to the circumstances and remarkably abetted by the collapse of mechanism. No doubt, too, the theory of preexistent germs was for many minds a purely scientific theory. But the character of the science of the period never allowed it entirely to lose its religious value, and it is important to keep this in mind in order to understand the attitude of those who attacked it or defended it down to its final consequences.

II] The Progress of the Doctrine (1680-1700)

Starting in 1680, the theory of preexistent germs began to take over the scientific world. The history of this conquest would be exceedingly complicated: first, because the doctrine itself now took on two forms, panspermia and the encasement of germs; second, because the scientific community was about to become divided between ovism and animalculism, and each doctrine was to interpret preexistence in its fashion; finally, because scientists and philosophers would often have very different reasons for embracing the same doctrine. All that can be done here is to note stages, point out the most frequently used arguments, and examine a few important theories. On August 12, 1680, the Journal des Savants reviewed Perrault’s Méchanique des animaux. The author was praised for his restraint on the subject of procreation, and it was pointed out that he was presenting a “new hypothesis, in which are found the reasons for the incomprehensible things encountered in other hypotheses.” But the reviewer said neither what this hypothesis was nor what he thought of it, and this silence cannot be taken as a sign of enthusiasm.*° ‘Two years later, the periodical reviewed some observations and notions of Swammerdam’s in greater detail, but still with reserve.?” Meanwhile, Joseph Guichard-Duverney had shown the Académie a fully formed little frog in the dark portion of the egg,”! confirming Swammerdam’s observations. It was also in 1682 that a doctor of medicine in Montpellier named Dedu, who was a botanist by predilection and a chemist and corpuscularist by conviction, published a book entitled De lame des plantes. Dedu avidly defended

the preexistence of plants in seeds, a theory based on the preexistence of animals in eggs.?* Until then, people had “quite needlessly tormented themselves” over how the parts of plants came to be arranged “so artistically.” “But now we do not need to engage in all those ingenious reasonings: we see that the seed is a miniature of the plant.” To be convinced of this, one

276 THE SCIENTISTS’ PHILOSOPHY needed only examine what had become the traditional point of reference, a tulip bulb, under the microscope. “If anyone asks after that how it comes about that, in this development, the roots are below, the stem in the middle, the trunk and branches at the top, the answer is that it is a secret of Providence; let us not be so bold as to look into a matter that goes beyond the scope of our minds.” It is clear that in this respect, Providence and the preexistence of germs had become the u/tima ratio of biologists who were out of answers. [his mentality was already in evidence in Perrault, but here it displayed itself ingenuously. It should come as no surprise that Dedu advertised his anti-Aristotelianism as well as his fidelity to Gassendi.°* We shall more than once encounter this pious version of Gassendist skepticism, which the English scientists had long since adopted. It is worth noting that De /@me des plantes was considered worthy of a detailed review in the Journal des Savants?’ In 1684, the physician Jean-Jacques Harder, in Basel, also cited Gassendi in explaining spontaneous generation by way of germs hidden in matter, which

was for him an additional proof of ovism.?* The third edition of Francois Bernier's Abrégé de la philosophie de Gassendi, which appeared that same year, was perfectly attuned to the taste of the day.”? There was the same admission

of impotence in attempting to understand the “internal and hidden economy” of the animal, and the same recourse to the “divine and incomparable Artisan” whose “praises one can but sing” for the fashion in which he created “these inimitable works, which surpass all our intelligence.” '°° Bernier was, of course, setting forth Gassendi’s various hypotheses about procreation, but readers in 1684 must have been inclined to pay particular attention to the one dealing with preexistent germs, in any case more fully developed than the others.'”' Then, too, it may have been Gassendi’s influence that impelled Bernard le Bovier de Fontenelle to insert a letter against the animal-asmachine right in the midst of [his anonymously published collection of tales] Lettres galantes du chevalier d Her . . . [1685], with the noteworthy singularity that the criticism, instead of repeating all the traditional arguments about the intelligence of animals,’°” centers only on their ability to reproduce: You say that animals are machines just like watches? Then place a dog machine and a bitch machine next to each other, and you will see that a third little machine may be the result; whereas two watches can spend their entire lives next to each other without their ever making a third watch. And so we have discovered through our philosophy,

Madame de B. and I, that all things that, being two and having the power to make themselves three, are of a nobility far above that of a machine.!93

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The argument was droll but serious. Mechanism’s inability to account for procreation would, as we shall see, play an important role in Fontenelle’s thought. This theme of the inability of motion to form a living being was not, of course, new. We have already encountered it in Gassendi, Boyle, Malebranche, and Perrault. Now, however, it had become a commonplace, repeated and developed at length. In 1686 and 1687, Malpighi republished his works, in particular his 1672 observations on the hen’s egg.'°4 This time they received a very favorable reception, enabling us to measure the ground gained in fifteen years by the theory of the preexistence of germs. Jean Le Clerc emphasized plant preformation and showed clearly that for Malpighi this was simply one type of preformation.’”° On the other hand, the Journal des Savants, which had been so guarded towards Swammerdam, went wild over the

preformation of the chick and immediately interpreted it as a proof of the preexistence of germs.'°° The major argument in favor of preexistence was that one could not “imagine that solely by virtue of the movement of fermen-

tation the parts of an egg could adopt that infinite diversity of placements and arrangements that they must have in order to constitute a chick. And who does not see that if fermentation were the sole cause of generation in animals, there would be more monsters than perfect specimens?” It was “impossible to understand how a substance that appears homogeneous . . . acquires form and changes itself into infinitely different organs.” On the other hand, “by following our author’s conjecture, it is extremely easy to understand that God, whose power and wisdom are without limits, has himself produced all the germs at the outset.” 1°” All this very clearly bespeaks the influence of Per-

rault. That this mistrust or even hostility toward mechanism rested upon a religious attitude comes out rather clearly in the 1689 review devoted by Le Clerc to the Physique véritable of the Cartesian Arnold Gueulincx.’®* In order to refute Gueulincx, who was guilty of having “believed along with Descartes

that by postulating matter and movement one could explain the formation of all bodies, as well as the reason for their structure,” Le Clerc could think of

nothing better than to refer the reader to a harangue by the pious Isaac Barrow in which Cartesian mechanism had been severely criticized from both the scientific and the religious points of view.'°? But since the hypotheses that Barrow had mustered against Cartesian mechanism were as dated as Barrow himself,""° Le Clerc decided that there was nothing for it but to “admit that we are not made to solve the enigma of nature, at least in this life.”"* The

278 THE SCIENTISTS PHILOSOPHY | inadequacy and impiety of mechanism and a resignation to necessary ignorance: these themes were tied to each other and developed conjointly with the preexistence of germs. It is important, however, to take note here of a fundamental confusion that greatly aided in the development of the doctrine, and that amounted to an identification of the laws of motion with chance. All the arguments about the inability of a mechanism to form a living being encountered both above and below were grounded in this confusion, which linked Descartes and Epicurus in joint condemnation. Whoever rejected final causes was regarded as bringing chance into nature, for one then had to accept that “everything that has the capacity to happen never fails to appear, whatever harm may come from it.” ’? Now, any animal was far too complex in organization to be the result of a “fortuitous arrangement” of matter. This criticism of the concept of spontaneous generation reappeared persistently—in Baglivi in 1699, Le Clerc in 1710 and 1719, Tilburg in 1724, Réaumur in 1736, and Bazin in 1741." But it was also used —and this is noteworthy — against regular generations achieved

through epigenesis. Every time there was mention of “fermentation,” of the motion of material particles, chance was invoked and legitimately accused of inadequacy. According to Father Noél Régnault, S.J., in 1729, one had to choose between preexistence and “the fortuitous encounter of some diversely stimulated juices.” It went without saying that Régnault chose preexistence, which was “at least plausible.” 114 Thus, it seemed impossible to accept that the order established by God could function solely by means of the laws of motion, whose action on living matter appeared far too general to explain such precise and complex phenomena. Nor was it clear either how the action of the parents could “direct” the motions of matter in the embryo. Relying on the laws of motion was therefore the same as relying on chance, which was above all absurd, but impious as well, for it amounted to denying the supernatural order of the world. How far Cartesianism had moved away from Descartes is fully evident simply in the fact that these themes are found united in the Cartesian PierreSylvain Régis in 1690. For him, God had created the first two plants of each species, which contained inside them the germs of all the others." He had likewise created a pair of each animal species.’’© All animals came from an egg, as Redi had proven."'” Malpighi had demonstrated that the chick preexisted in the egg, and this was the only way of envisaging generation, for “fermentation” would be powerless to form an animal.'® But how were we to envisage the preexistence of germs? Panspermia would have us believe that

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females imbibed the germs along with their nourishment. In that case, digestion would destroy them, and, in any case, this theory was too complicated, since it required two actions, the creation of the germ and its placement in the female organs.’”? Other authors identified germs with the animalculi of the semen in order to preserve the role of the male parent in generation.’”° As for himself, Régis accepted “according to Monsieur Malpighi’s conjectures, that all the germs are formed in the eggs, independently of the male semen.” '”! Where insects were concerned, there was neither spontaneous generation nor metamorphosis but preexistence in the egg and then development, as with the other animals.’*? Régis brings in all these notions with respect to man: creation of the first couple, preexistence and encasement in the eggs, and the powerlessness of mechanism.'*’ The system had now been completely established, well armed with all its arguments drawn from observation and reasoning. [he “Cartesian” Régis was thoroughly deserving of the compliments paid him by the anti-Cartesian Le Clerc:!24 he had betrayed his master to perfection. After Régis, the ovist conception of the preexistence of germs was solidly in place. Edmond Pourchot adopted it in 1695 as the only plausible theory in an area where “human reason must put off all its splendor, and man must admit his ignorance.” ’?? He invoked the authority of Harvey (for he effectively confused ovism and preexistence), that of Malebranche (by now classic), and the infinite divisibility of matter.’?° All the traditional themes were thus gathered together in an unoriginal vulgarizer, but one who nonetheless bears reliable witness to his period. There was nothing original either in the German “Cartesian” Johann Waldschmidt, of the same period, who based his belief in preexistence on the admirable construction of animals and on the analogy with plants.!’” There was nothing new to hope for in this area except for some unexpected observation, such as Gaspard Bartholin’s on the baby girl who was already pregnant at the moment of her arrival in the world— splendid proof of the encasement of germs! !° In 1688, Claude Perrault had noted the poor success of his hypothesis concerning panspermia: “I employ a system that is known to only a few people,” he wrote. “Of all the new systems that have been proposed in physics, I do not think any has been found that has been more roundly rejected, and yet less combated with reasons, than this one.” !? We have seen Régis quickly refute it in 1690. The great problem with panspermia was that it fitted in poorly with ovism, for it required that the germ be swallowed by the female before taking up residence in the egg, which was not very plausible. Panspermia was

280 THE SCIENTISTS PHILOSOPHY able to enjoy some limited success thanks only to the discovery of the spermatic animalculi, but Perrault died too soon to see this development. Despite the testimony of Robert Challes,’®° the idea that the preexistence of germs in spermatozoa had been overwhelmingly successful since 1682 cannot, in fact, be accepted. We have seen how hard it was for Leeuwenhoek to formulate his ideas on the nature of the spermatic animalculus, finally accepting that the embryo was preformed, without, however, believing that the germ had been created since the beginning of the world. The application of the preexistence of germs to animalculism was carried out by others than Leeuwenhoek, perhaps by Hartsoeker and Wilhelm Homberg, whose ideas Régis discussed in 1690.'*' But it was the Briton George Garden who provided the new system with its clearest expression in 1691.'°* Regarding preexistence itself, Garden’s thinking was absolutely classic: he drew support from the observations of Malpighi and Swammerdam and from the plant analogy;’* he disparaged the inadequacy of the currently known laws of motion to explain the formation of a living being, as Descartes’s failure had demonstrated;!34 and he recalled, in terms very close to those of Malebranche, that only the nature of our vision prevented us from imagining infinitely small beings.’** In the circumstances, it seemed “highly probable that the rudiments of all plants and all animals that have existed and that will ever exist in the world have been formed ab Origine mundi by the All-Powerful Creator, inside the first individual of each species.” 13° After the experiments of Régnier de Graaf, it was possible to believe, like Perrault, that the preexistent germ was in the egg. But since Leeuwenhoek’s discovery, it had to be admitted that it was in the spermatic animalculus.'*’ This was Garden's sole claim to originality, and he seems, moreover, to have rejected panspermia, but without explaining himself as to the manner in which the preexistent germ had been preserved since Creation. We know that in order to save the basic premise of ovism, Garden hypothesized that the germ could develop only in an egg. But the ovists, convinced of the existence of the germ in the egg itself, could not accept this interpretation. The theory of preexistence necessitated the idea of a unique germ that was the animal itself “in miniature.” No compromise was possible, therefore, between ovism and animalculism. By forcing the two doctrines to oppose each other in this way, the preexistence of germs weakened both and held back by a century our knowledge of the phenomena of reproduction. In 1694, Hartsoeker finally expounded his ideas, which were very close to those of Garden; but he very explicitly adopted the encasement of germs in

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the spermatozoa, “so that according to this thought the first males would have

been created with all those of the same species that they have engendered and that will be engendered until the end of time.” ** Hartsoeker, who liked to give the impression that he had created everything, did not cite any authority, but readers no longer required any. Garden had published his article in Philosophical Transactions, and the Journal des Savants published a long “extract” [1.e., digest— Tr.] of Hartsoeker’s text.'? “Vermist” preexistence could

no longer be unknown to anyone. A few weeks after having reported Hartsoeker’s ideas, the Journal des Savants published the “Systeme nouveau de la nature et de la communication des substances” in which Leibniz, basing himself on the observations by Swammerdam, Malpighi, and Leeuwenhoek, “the most excellent observers of our time,” and on the examples of Malebranche, Régis, and Hartsoeker, adopted the new system in order to sustain philosophical positions to which we shall return.'*° It was in 1700, with Nicolas Andry, however, that preexistence in the spermatic animalculus was set forth in the most complete and detailed form.'*! Andry’s arguments cannot be expounded here without repetition, for we have encountered them all before. Andry’s originality was to have brought them all together, albeit with a certain predilection for arguments of a religious nature.'4? He constantly quotes Malebranche and, rather than emphasize the inadequacy of mechanism, he stresses God’s omnipotence and the wealth of Creation, which our imagination cannot envisage, but that experience partially reveals to us.'43 In this sense, Andry foreshadowed Réaumur, who was

also so clearly influenced by Malebranche. Let us add that Andry was ready : to accept panspermia where parasitical worms in men were concerned,'“4 but

that for man himself, he finally came down in favor of encasement in the sperm cell, “a thought that can seem bizarre only to those who measure the marvels of God’s infinite power according to the ideas of their senses and their imaginations, ‘4° exactly the same formulation as in Malebranche. Andry’s success, followed soon after by that of Etienne-Francois Geoffroy, decisively placed vermist [i.e., animalculist] preexistence on the same footing as preexistence in the egg. Geoffroy even attempted to push his advantage by showing

that no one, not even Malpighi, had been able to see the embryo in the egg before fertilization, which clearly proved that it was not preexistent therein.'4° We have seen that ever since Malebranche both versions of animal preexistence had cheerfully rested on the analogy with plants. In 1675, Malpighi had conversely established vegetable preformation on the model of animal

282 THE SCIENTISTS’ PHILOSOPHY preformation.'*” Here again, Malpighi’s observations, which tended only to prove preformation and deliberately eschewed the problem of the origin of the seed, were interpreted as the proof of a preexistence of vegetable germs, whose existence was soon beyond doubt. Leeuwenhoek clearly asserted as much in 1685, in a lapidary formula: “The seed . . . does not have its first origin in the tree, but in the seed from which the tree has issued,” which he proved with careful observations.'48 In Paris, the Académie heard a reading of notes by Joseph de Tournefort in 1694 that concluded in favor at least of preformation.'4? With the two reports of Denis Dodart, read to the Académie in 1700 and 1701, doubt was no longer permitted: it was indeed a matter of preexistence. A close friend of Monsieur Hamon’s, whom he assisted in his final moments and whom he succeeded as doctor at Port-Royal, Dodart was a highly religious spirit.’*° At the same time, he was a very precise scientist who did not confuse facts with conjectures.’*! Regarding animal generation, Dodart shared the views of his friend Andry.’°? Concerning plants, he thought things proceeded as with animals: all growth required the presence of a germ, “which assumes preexistence not only of the leaf bud, but a fruit bud, that is, seeds and the whole apparatus for multiplication.” ’°? Matter was divisible to infinity, and all these encased seeds did not make up a great mass.'*4 The major objection remained that of Perrault: this system brought us back “directly to the miracle of Creation,” it introduced “God as into a machine.” Dodart’s reply deserves quotation: When one has examined all the systems that can explain new generations: if one finds nothing that satisfactorily explains them; if one finds, even, in the general order of nature an indispensable and ironclad necessity to postulate encased preexistence,

| then who can blame the scientist for saying that nothing new came into existence? It seems to me, then, that it is more philosophical to think that God created everything at the same time. . . . This does not mean introducing God into a machine where He is not, but finding Him where He is while exploring nature. Now, far from this being a drawback in physics, it is the most noble use of physics that it leads us

to the end, and that nature itself in its entirety is made only for that.!>> There is a discreet Augustinian reminder here of the inadequacy of systems—which is to say, of mechanics and of nature itself—to explain generation. To all this, which was already to be found in Perrault, Dodart added his profound conviction that the marvels of nature existed only to lead man to God. This was indeed the same spiritual current, but twenty years had passed;

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the eighteenth century was dawning. After Dodart, it would no longer be possible to doubt vegetable preexistence. Etienne-Frangois Geoffroy was able

to derive authority from him in 1704 and to devote the core of his famous thesis to demonstrating the unity in the ways of nature, which made use of preexistent germs everywhere.

IV Resistance (1675-1700)

The desire to see nothing in nature except purely material phenomena and a purely passive conception of nature—which led scientists, finally, to concede all creative activity to God and to proclaim the inadequacy of mechanism —were both significant influences on the doctrine of the preexistence of germs in the final third of the seventeenth century. The resistance encountered by the concept of preexistence was a resistance to these same tendencies. The spiritualist chemists rejected a materialist vision of nature. But they were few in number, at least in France, and I mention them only for the sake of completeness. More numerous and more important were the minds attached to a “lay” and mechanistic vision of the world. We already know them: they were the scientists of Cartesian and Epicurean inspiration (the two, as we have seen, tended to merge) who rejected the major tendencies of the new science: its exclusive taste for observation, its admissions of ignorance, and its constant recourse to the divinity. They were the supporters of the unofhcial journals, the admirers of Guillaume Lamy, and the opponents of nascent ovism, to whom would be added (without them always quite realizing it) a handful of faithful Cartesians, corpuscularist chemists, and stubborn Galenists. We know that they were battling for a temporarily hopeless cause, but the battle is worth recounting, if only for the details of shading that it offers and for the building blocks that it put in place for the future. Before speaking of those who openly rejected the preexistence of germs, I must at least cite a few of those who seem to have been quite unaware of the concept. The matter was simple for the chemist Giuseppe-Franceso Borri, who in 1669 attributed the formation of the embryo to a chemical arrangement of particles under the direction of an “immortal virtue” that was “so to speak the seal of God.” !°° In 1678, David von der Becke remained enclosed in the same chemical universe even though an ovist.’°’ Although a disciple of Helmont’s, he was nonetheless affected by the mentality of the time to

284 THE SCIENTISTS’ PHILOSOPHY the point of vaguely envisaging a kind of preformation in the blood. But it was still “the male parent’s idea” that played the essential role. In 1703, Becke would still harbor the same opinions.’** A few traditional physicians were as obstinate as the chemists. Girolamo Barbato, a case in point, was still an Aristotelian in 1671 and even in 1676 explicitly rejected the viviparous egg.’*? Isbrand van Diemerbroek was a Galenist and anti-ovist in 1672,'°° and subsequently a convert to ovism, but he was

always faithful to an epigenesis directed by an architectonic virtue.!*! The well-known obstetrician Francois Mauriceau, in 1681,!° and his colleague Philippe Peu, in 1694,'° were still looking to “faculties” or “nature” to form living beings. The new spirit had obviously passed them by. Finally, many physicians who had made the effort to convert to mechanism or chemicalism, or to both together, were never to experience doubt or even know of the existence of another doctrine. Two examples are Antoine Legrand, a French Cartesian established in England,'°4 and Francois Bayle, whom the Journal des Savants would say was “quite fond of the opinion of Monsieur Descartes.” '©° In 1685, Charles Drelincourt believed in epigenesis through fermentation and the activity of the “acido-saline male atoms,” !° whereas in 1687 Heinrich Herfelt was strictly Cartesian,'©” something that no longer pleased the Journal des Savants.'°8 Lorenzo Bellini was too deeply committed a mechanist in 1696 even to accept discussion of some sort of preformation.'®

The same did not hold for a small number of Cartesian physicians and chemists who displayed more sensitivity to the spirit of the time, although the concept of preexistence, properly speaking, does not seem to have touched

them. As early as 1663, the Italian Cartesian Thomas Consentini clearly accepted preformation, which ties him to the tradition of Giuseppe degli | Aromarari.'’”° The chemist Jean Pascal took pains in 1681 to explain how “the _ blind movement of the particles of the semen” could form an embryo. Therefore, he accepted the notion that semen was derived from the whole body, that it was simply “a miniature of the parts,” and thus that “the parts of the

semen that derive from a particular member will be set up only to form a like member.” '”? Pascal thus found himself very close to Lamy, and it is quite

remarkable that preformation conceived in this fashion should have been destined to become a weapon in the hands of those seeking to attack preexistence, which was not yet the case with the scientists at whom we have looked. The first attack officially directed against the concept of preexistent germs was launched by Duverney in Nicolas de Blégny’s journal Le Temple d’Escu-

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lape. The “ovarists” claimed that “their so-called eggs contain in miniature all

the parts of the fetus.” But in that case, what was the male for?!’ Clearly, Duverney rejected preformation as well as preexistence; he still, in fact, accepted the mingling of the two homogeneous seminal fluids. Johann Bohn, in 1686, believing that the male semen formed the embryo through its movement, rejected preformation.'’? Theodor Craanen took the same stance in 1689: the male seed was the “true former and begetter.” The embryo was no more preformed in the egg than ice crystals were preformed in water.!”4 One senses among all these doctors the desire to preserve the role of the male in generation. But these absolute partisans of epigenesis were out of step with the movement of their time. Craanen died in 1688. Bohn was a belated Aris-

totelian. Duverney was going to be converted. The only ones who would be able to resist preexistence were those who at least accepted preformation. By 1698, Claude Brunet was the only one left who believed that “animals are formed automatically as they are ready to appear,” preexistence having the great fault, according to him, of taking away from God “a particular mark of Divinity, which is to do in the present for the preservation of the World what He did at the beginning in order to produce it.”'”° Clearly, Brunet had acquired the taste of the day, but he remained nonetheless a belated disciple of Descartes and Gassendi. The most numerous and prominent among the opponents of preexistence —those we are now about to examine—were not able to remain so separate from the ideas of their time. Some accepted preformation, which seemed proven by Malpighi’s observations. Others remained faithful to epigenesis, while acknowledging at the same time that it was incomprehensible and even unimaginable. In 1681, Giovanni Alfonso Borelli rejected preexistence in the egg and refused to believe “that the male semen brings nothing to the egg other than a moving force, or that organization in its entirety depends upon the woman.” '”° But he accepted a double preformation or preordination of the seminal particles in the female egg and the male semen. The two “vital automata thus produced united with each other to constitute the embryo,'””

which in turn received the movement of the male seed through a kind of magnetic communication.'”* Borelli’s thought, although not entirely clear, visibly parallels that of the preformationists of 1625: the preformation of the seed was assured by the parents, thanks to appropriate organs. Which means that he judged “fermentation” and the “laws of motion” incapable of assuring the arrangement of the seed’s particles. As for the emanation of souls, it had become a communication of the vital movement: the embryo was like

286 THE SCIENTISTS PHILOSOPHY a clock whose pendulum needed to be set in motion, but that would subsequently function by itself.’”’ Thus Borelli was able to remain a mechanist without assigning to the laws of motion the formative power that Descartes had assumed they had, and in which no one any longer believed. The chemist and mechanist Daniel Duncan, writing in 1686, was singularly hesitant, but his ideas seem quite close to those of Borelli, with the one exception that it was a “genital spirit” that had to stimulate “a movement in the parts of the egg that changes their shape and their situation, and makes them adopt those that they must have to constitute the fetus.” Duncan conceded that the operation was difficult to imagine, but, he said, “the difficulty one has in understanding how movement can produce so fair a work is not a demonstration of its inadequacy.” '8° This remark may well have been addressed to Perrault, of whose ideas Duncan was aware.’*’ Duncan accepted preformation, which was proved by observation,'*” but his definition of life reflected a less modern thought: The principle of life is a rarefied and extremely active matter, which is imprisoned in the encumbering portions of the coarse matter. This is what Descartes calls his first element, and Gassendi, following Epicurus and Democritus, his active atoms, whose efficacity consists in present movement or in the great disposition they have to move. It is the air or fire of the Peripatetics [Aristotelians]. It is the spirit, the mercury, or the essence of the chemists.!84

In this way, all the ideas of 1650 united in a chemical-mechanical synthesis that opposed the new science. Cornelius Bontekoe, whose Metaphysica appeared posthumously in 1688, displayed much less certainty. “On the mode of formation of the members, nothing definite may be said,” he wrote. Malpighi’s observations permitted belief in preformation, but in reality, “the formation of the fetus is still unknown to us.” !84 This admission of uncertainty could be likened to the position of Pierre Bayle, whose articles on reproduction appeared in quantity the same year.'®° Bayle, of course, rejected “souls” and “faculties.” “It seems, then,

that we are to invoke only the laws of communication of motions, but those who have most painstakingly studied them do not understand how they suffice for the formation of so many organs.” 18° In his Dictionnaire historique et critique, Bayle went over the question again at length and admitted that the preexistence of germs “dissipates the unimaginable difficulties one finds oneself in when one tries to designate a cause for organization.” But he was even more skeptical than his contemporaries with regard to the laws of motion. People accepted the idea that these laws, “however simple, however few in

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number, suffice to make a fetus grow, provided that one assumes they find it already organized. But I admit my weakness: I cannot understand this. It seems to me that for a little organized atom to become a chick, a dog, a calf, etc., an intelligent cause must necessarily direct the movement of the matter that makes it grow.” This cause cannot be God directly, for “to present God

as the entire reason in this investigation is not to philosophize.” There has , to be a secondary cause, but “the difficulty lies in saying what this secondary cause is.” It could not be our soul, which knew nothing about the order required for the body. In the end, had one not to assume “a created Intelligence _ that presides over the organization of animals,” somewhat in the manner of Avicenna’s Colcodea?’®’ One may surmise that Bayle was very close here to admitting the existence of this “intelligence,” which would differ from the “hylarchic principles” of Henry More or the “plastic natures” of Ralph Cudworth in that it would have “received from God the knowledge and industry” necessary for the work, whereas “principles” and “natures” acted unknowingly.’** In this case Bayle would have been foreshadowing the “rectifying intelligences” of Nicolas Hartsoeker.'’*” Must we conceive that Bayle envisaged this intelligence as indissolubly linked to each atom of matter?!?° It is difhcult to say with certainty and, in any case, Bayle did not categorically assert the existence of this “intelligence.” What is clear, however, is that his radical skepticism destroyed all the hypotheses that still granted some power to the

laws of motion. Going further than his contemporaries, he thus destroyed the notion of the preexistence of germs, even if abetted by an animism 4 la Perrault. And finally, was discovering a “secondary cause” the same as imagining this created intelligence to be the great producer of living beings? Would

it not be better to introduce “God as in a machine” candidly, like Dodart? In his fashion, Bayle, too, took everything away from nature to give everything to God. On many important points, he plainly endorsed Antoine Arnauld rather than Malebranche.’?’ But in any case, he was linked to no one, and the original position that he seems to have adopted set him apart from almost all his contemporaries. He was still very close to all those outdated scientists whom he knew so well, including Sennert, Francois Titelmann,

Alonzo Caranza, and Henry More. Bayle knew too many people, too many | things, too many ideas. A contemporary of Malebranche’s and Leibniz’s, he saw better than anyone how closely the new problems resembled the old, how old the newest theories were. One might say that he had seen the birth and death of Descartes, and his wisdom had something of the eternal in it. He did not follow his age, he walked alongside it, on a path of his own. He

288 THE SCIENTISTS PHILOSOPHY understood the concept of the preexistence of germs, just as he understood occasional causes and preestablished harmony—but he saw the limits of all of them, and no dogma could keep him captive. Nothing particularly new is to be found in old Caspar Posner, who rejected preexistence in 1692 out of loyalty to Aristotle,’®* or in Jean-Baptiste Verduc, who was content in 1696 to add to Bohn’s comments a criticism of preexistence in the animalculus, understood as a form of panspermia.'”? In contrast, Pierre Dionis was a modern scientist who examined all problems exhaustively.

Now Dionis succeeded nicely in bringing Lamy and Malpighi into agreement on the subject of preformation. And “if we find it hard to understand how it can be that a woman’s egg contains a whole and well-organized fetus, we should reflect on things in nature about which we harbor no doubts and that nonetheless go beyond our imagining.” !°4 Therefore, “the fetus is contained in the egg, but knowing how it has been formed in this ege is the great problem.” 1”? Encasement, a la Swammerdam, “should not seem so ridiculous as it might at first appear . . . the infinite divisibility of matter having been established.” Still, Dionis conclusively accepted neither the one nor the other. Not only was there the problem of teratisms (to which we shall return), but it seems that preexistence was deeply unacceptable to Dionis. He found it impossible not to believe that “the fetus is being formed every day in the eggs,”

even if he could not “explain all these things in their particulars.” !°° This understanding of things appeared more natural to him. After all, it “assumes only that God does the same thing today as people say he did at the beginning of time.” 1°” The distinction did not seem a very great one to Dionis, who was not a philosopher and lacked Bayle’s scruples. Starting out with Guillaume Lamy only to end up with God, Dionis in his way demonstrates the incredible bankruptcy of mechanism in the last twenty years of the seventeenth century. With Dionis, preformation became incomprehensible. It nonetheless remained the last resort of those who, without accepting “faculties,” “souls,” or “plastic natures, could not resign themselves to the preexistence of germs. Even without being able to explain the phenomenon, they could accept that

the organs of the male parent provided the particles of the semen with the appropriate disposition. The organs functioned as an internal mold for the particles. And this image of the organic mold, which Buffon was to restate with such brilliance, appeared precisely in this final stage of the seventeenth century, among the last mechanist opponents of preexistence. It is found in Bayle, who saw in it a possible, although not fully adequate, explanation for the growth of the preexistent embryo,'”® recalling, moreover, the connections

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already established by the old doctors between nutrition and reproduction, connections Buffon was not unmindful of either. For Charles Delaunay, in 1698, the male semen was formed of vital principles that took on their final disposition in the testicles, “which would serve them as molds.” ”? An anonymous writer, around the same time, expressed himself more precisely regarding plants: The sap in the root is brought to the branches; where there are nodes, there comes together a tissue of veins, arteries, and nerves; the sap remains in these parts, it enters all the byways and the fibers, where it is stopped and receives the form of the seed; there is a mold that patterns all the parts of the tree; we cannot see the different parts of the mold, for our vision is not sufficiently powerful.?°°

This was certainly not very clear, but how could one do any better without accepting preexistence? In fact, in 1705 another anonymous writer would pick up the old idea of “nutritive parts” that, inside the organs of the male parent that they have been preparing to nourish, adopt the order and shape that will enable them to reproduce a particular organ. In this way one could say that “one organ provides the mold for another.” *°! The specters seen in cemeteries, formed from the “rich and rarefied particles exhaled in the dissolution of the body,” whose form they retained, might serve as an example.”°? For it was impossible to use mere motion as an explanation.””° Thus, these final successors to Lamy bequeathed nothing but an image to Buffon. At least this image expressed the conviction that the phenomena of life were mechanistic—that is, natural—and that it was better, after all, to leave a bit of obscurity in the explanations than to bring in God, who explained everything far too well. This was a truly philosophical conviction, for looking at the facts, a scientist might despair. The Trazté de la génération that Daniel Tauvry published in 1700 was a genuine confession of inadequacy. “However we torment our minds, we cannot understand the generation of anything at all,” he acknowledged from the outset.?% In order to explain through the laws of motion the formation of the body of a man or of some other animal, one must begin by formulating the principles of the least fiber, one must draw precise distinctions between the arrangement of the small parts of a nerve, a muscular fiber, a bone, etc., but as there is little likelihood of uncovering these mysteries,

it was pointless to throw oneself into investigations doomed in advance to failure. For, although generally speaking one may say that everything that strikes our senses is no more than an arrangement of matter produced by the laws of motion, this does not

290 THE SCIENTISTS PHILOSOPHY shed much light on the datum in question. In fact, this general and metaphysical kind of knowledge always leaves us in real ignorance, since we cannot use it to determine through what laws particular bodies have been formed.”

Nonetheless, Tauvry rejected preexistence, encasement (which obliged us to “assume a smallness of size beyond all imagining”), and panspermia (which failed to explain how germs filtered into the ovaries or the testicles).?°° He could no longer, however, pass for a champion of mechanism, which for him was merely a “general and metaphysical kind of knowledge.” A combination of particles due to an action of spirits was merely “philosophical gobbledygook” in his eyes and could “fool only people who are content with words.” *°” In reality, Tauvry was very close to the critical stance of Bayle. Between supporters and opponents of preexistence, there was no longer any difference except in the manner of not knowing. This difference existed, however, and albeit purely philosophical, it was very important: it was a question, in fact, of knowing whether nature was or was not capable of forming a living being.

This was the true meaning of the battle against the theory of preexistent germs, although the scientists waging the battle may not have been clearly aware of it. This is why a man such as J.-F. Vallade, who, while accepting only preformation, had it depend directly on the will of God acting in the present

“to bring animate creatures out of matter,” must be ranked among the partisans of preexistence.”°* Here, as with preexistence, nature was stripped of all power. The same opposition emerges still more clearly if we compare Vallade’s writings with those of Joseph Besse, who at the dawn of the eighteenth - century was one of the last mechanist opponents of preexistence. Besse knew very well that we could provide only an abstract notion of the formation of a living being: “The weakness of our mind does not allow us to proceed any further, and without understanding the proportion and the admirable arrangement of the parts that compose the machine, we can do naught but admire them.”*°? But Besse rejected preexistence, “because it would have been pointless to form all eggs at the same time, since the same laws by which God formed the first man still being in force, the eggs could have been formed thereafter, and if the laws were sufficient for stimulating certain parts of matter, to bring them in contact and unite them in such a way as to form Adam and Eve, it is inescapable that being still the same they must have the same effect.”?!° Besse, it is clear, remained faithful to the principle of Cartesian cosmogony. And what lent importance to this way of seeing things was that it was only necessary to maintain that all living beings did not issue directly from the hand of the Creator, and to maintain instead that nature could form

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a living being, in order to be directly led to consider that formation the object of a possible science. Besse, who had spoken of simply admiring nature, immediately contradicted himself: Perhaps those writing after us will be able to undertake to determine the laws and means that collaborate in this formation: the knowledge that Monsieur Descartes gave us of the production of the universe . . . gives us hope of being able to discover one day the paths by which a portion of matter takes the form and arrangement of which the human body is constituted. It is true that this enterprise contains incomparably more intelligence than the rest of the world: the order, the form, the mechanics, and the play of all the parts of man are far more admirable and hidden; but we may also be certain that there is nothing so complex nor so awkward that the human spirit cannot conquer it.7"?

In 1702 Besse was an isolated figure and was made to feel as much.”* Later,

he would be forgotten. At the moment when the dominant philosophy was increasingly giving up on understanding nature, his work was both a remnant of the past and a hope for the future, a kind of fragile link between Descartes and Buffon.

Vy

The Theory Made Official (1700-1745)

After 1705, preexistence would reign over official science unchallenged. Mechanism’s inadequacy had been established, and there was nothing to fear from that direction. The medical tradition had been breached: although Pierre Amand, in 1714,” and Mauquest de La Motte, in 1718,7"4 continued to reject the new doctrine, the conclusion drawn was that they were good obstetricians but bad physiologists. Was La Motte himself not obliged to acknowledge that the formation of the embryo was “a mystery that has until now remained impenetrable,” even to the renowned Monsieur Lamy?*”? That crowd was not dangerous. There remained, then, a few spiritualist chemists, a few stubborn admirers of Helmont, defenders of the archei, of acids and alkalis, who were sometimes good Augustinians but of a type that had gone out of style. Such were Martin Heer,”!® Jean Dartiguelongue,”'” Carlo Musitano,*** Andreas Riidiger,””? and Dr. Hunauld.”*° These were people who supposedly had outlived their time, as certain critics did not hesitate to let them know,7”! without perhaps realizing that the animism of Riidiger and even of Heer was not as dated as one might have thought, and without seeing that these outmoded theories were beginning to take on a more modern face. The triumph

292 THE SCIENTISTS PHILOSOPHY of the concept of preexistence rested less on its merits than on the inadequacy of other theories. This very inadequacy, however, or at least the importance that was given it, derived above all from the mentality of the time. The perfect

agreement between the theory of preexistent germs and the thought of the period had already been evident in Malebranche. It appeared just as clearly in Fontenelle and Leibniz—and this coincidence among three such different philosophies is truly remarkable. Just as with Malebranche, it is out of the question to attempt to set forth the whole of Fontenelle’s thought here;??* the following discussion is thus

limited to the place occupied by the preexistence of germs within it. Fontenelle was undoubtedly a mechanist, and an old-style mechanist at that, who conceived only of communications of motion and held as suspect all recourse to a forcelike attraction. But like nearly everyone since 1650, he did not be-

lieve that the laws of motion could create anything, especially not a living being. He had said as much in expounding Perrault’s theoretical system.’ He had restated it for his own account and had even based a proof of the existence of God upon this inadequacy of mechanism.?*4 This amounted to turning God into the “catalogue of our principal difficulties.” ??° These difhculties were, however, common to the entire period. They arose from the taste for clear ideas, from a great prudence regarding hypotheses, and from a certain conception of nature. The skepticism of Gassendi had joined forces with the piety of Barrow, and the unbeliever Fontenelle agreed with the Jansenist Dodart. All joined together against Descartes to assert that animals, like the stars, required a God to have created them.?*° What was more, for Fontenelle, Cartesian thought belonged to a bygone age when people still believed in the daydreams of the ancients on spontaneous generation. Now, “we must come back to certain rigorous philosophical principles.”?*” Nature was fixed and orderly, and the fixity of species was the justification for the attitude that Fon-

tenelle adopted in the quarrel of the ancients and the moderns: “Once the whole issue . . . has been clearly understood, it boils down to knowing if the trees that stood of yore in our countryside were larger than those of today.” 77°

Now nothing allowed for a better understanding of the permanence of animal forms than the theory of preexistent germs. In the last analysis, this theory made “generation conceivable,” ?”? for it would scarcely be conceivable otherwise. Not that Fontenelle made a certainty of it; but ultimately he took

it to be plausible, perhaps for lack of anything better and as the sole means of preserving biological mechanism, which was indispensable to anyone who

The Preexistence of Germs 293

wished to preserve a clear idea of nature. One may wonder if preexistence, for Fontenelle, was not less an objective reality than an artifice that permitted the building of a science through elimination of the unknowable. But it is hardly possible to arrive at an unequivocal judgment on this question. Although Leibniz came from an intellectual milieu different from that of Fontenelle, and the originality and the power of his thought make all comparison risky, it is not impossible to find historically rooted analogies between the two philosophers, particularly as regards their recourse to preexistent germs.?°° Like Fontenelle, Leibniz was convinced “that the laws of mechanism all alone cannot form an animal, where nothing as yet is organized,” and he severely criticized what “Monsieur Descartes imagined in his version of man, whose formation is achieved at little cost, but who ends up not very close to real man.” For “matter arranged by divine wisdom must essentially be organized everywhere; and . . . thus there are mechanisms ad infinitum in the parts of the natural machine.”?*? This notion of infinitely extending mechanisms certainly goes beyond the thought of Fontenelle, by virtue of the metaphysical leap it presumes. But it is quite remarkable that Leibniz, like Fontenelle, used the preexistence of germs to defend mechanism. This attitude is still clearer with him, for he was better acquainted with and more disposed to take seriously certain new doctrines that seemed to resuscitate dead systems: for example, Cudworth’s “plastic natures” (discussed further in Chapter 7), to which Fontenelle makes only one disdainful allusion.?” Leibniz specifies, then, that “since animals are never formed naturally from an inorganic mass, mechanical processes, incapable of reproducing these infinitely varied organs, may very well draw them through development and through transformation from a preexistent organized body.” There was thus “no need to have recourse along with M. Cudworth to certain immaterial plastic natures.” *°? For Leibniz, as for Fontenelle, “where the movements of the heavenly bodies and, still more, the formation of plants and animals are concerned, there is nothing in them that partakes of the miraculous, except for the beginning of these things. The organism of animals is a mechanism that assumes a divine preformation; what comes later is purely natural and utterly mechanical.” **4 In this sense, mechanical processes maintained rather

than formed, and would be all the stronger the less one demanded of them what they could not provide. Still, for Leibniz, the subordination of mechan-

ics was first of all a metaphysical subordination,?*? whereas for Fontenelle it would seem to have involved a physical inadequacy.

294 THE SCIENTISTS PHILOSOPHY The essential problem that impelled Leibniz to adopt the theory of preexistent germs was, however, still more foreign to Fontenelle’s thought: the problem of substance. This is how Leibniz tells of his successive reflections: At first, when I had freed myself from the yoke of Aristotle, I subscribed to the void and to atoms... ; but having abandoned these ideas, after many meditations, I perceived that it is impossible to find the principles of true unity in matter alone, or in what is merely passive. . . . I therefore had to summon back and rehabilitate, so to speak, the substantial forms, so scorned today. . . . I found, then, that their nature consists in power, and that there follows from that something analogous to feeling and appetite; and that in this way it was necessary to envisage them on the model of the notion we have of souls. But as the soul must not be used to account for the specifics of the economy of the animal’s body, I judged likewise that I could not use these forms in order to explain specific problems in nature, even though they may be necessary in order to establish true general principles. . . .

I saw that these forms and souls had to be indivisible, like our mind. ... But this truth brought back the great difficulties concerning the origin and the duration of souls and forms. For every substance that possesses true unity cannot have its beginning or its end except by miracle, and it follows that they could only have begun through creation, and end through annihilation. Thus, excepting the souls that God still wishes to create deliberately, I was obliged to recognize that the constitutive forms of substances had to have been created with the world and that they still exist . . . and this is where the transformations proposed by Messrs. Swammerdam, Malpighi, and Leeuwenhoek, the most excellent observers of our time, came to my aid, and allowed me to accept more easily that the animal, and all other organized substances, do not begin when we think they do, and that apparent generation is merely a development and a kind of augmentation.?°

This is an important text from many points of view. Note especially the manner in which Leibniz goes beyond the Cartesian conception of substance and mechanism. On the scientific level, Leibniz found himself obliged to bring in the notion of force.?*” On the philosophic level, he could not conceive of a purely material and passive substance. By allowing him to believe that all animal forms had existed since the creation of the world, attached to the organized bodies they animated, the hypothesis of the preexistence of germs gave him the means of escaping the insoluble difficulties raised by the origin of forms.?3* But by considering the germ to have been endowed witha soul from the beginning of time, Leibniz turned it into an entity possessing its own energy and very different from the merely passive mass of organized matter envisaged by his contemporaries. These dynamics also explain the choice Leibniz made among the available doctrines. Already in 1672, with the appearance of ovism on the scene,

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he had thought that “the souls are in the human egg, before conception.” *%” One may well surmise that Leibniz was led to this notion by conversations in Parisian circles in which Perrault’s theory of preexistent germs was already under discussion.”*° At that time, Leibniz was under the sway of “modern authors” and their “fine ways of explaining nature mechanically.” 741 But the

evolution of his thought tended to distance it from the purely passive preexistence to which ovism best lent itself. On his return to Germany at the end of 1676, he went to see Leeuwenhoek in Delft.?4? It was not yet a question of spermatozoa, and it was only in 1686 that the German philosopher was at last

able to adopt “vermist preexistence,” 43 in which he found exactly what he | needed. The spermatic animalculus, about whose need for a principle of motion or a soul, starting with Creation, Leeuwenhoek had written,”“* perfectly represented this organic body by which “each soul, or monad, is always accompanied . . . but which is in perpetual transformation.” 74° For the “worm” was not inert: it was a living animal that nourished itself, and whose body, consequently, was continually and imperceptibly changing in substance, “so that the body is not the same, even though the souls and the animal are.” 74° At the moment of conception, the animalculi “take on a new covering, which they make their own, and which gives them the means to nourish themselves and to grow, in order to move into a larger arena and carry out the propagation of the large animal.” 247 In this way Leeuwenhoek’s very obscure idea that spermatozoa gave birth to men without themselves being men acquired an explanation. At the same time, Leibniz avoided the accusation of assuming a necessary massacre of human embryos. For “the souls of spermatic human animals are not rational, and do not become so until conception determines a human nature in these animals.” 248 This transformation, or “transcreation,” of the human soul required intervention by God.?4? One might also assume that those animalculi destined to become human beings already possessed a rational soul, which would explain how all souls had been affected by original sin.*°° In any case, the worms that were not transformed into men remained simple animals.””’ As such, moreover, they could not really die, for if souls or

animal forms could not emerge in the course of nature, neither could they disappear. And as “it does not seem very reasonable that souls should remain with no function in the chaos of formless matter,” there was “only one reasonable stand to take: that of the preservation, not only of the soul, but of the animal and of its organic mechanism as well; although the destruction of the coarse portions would have reduced it to a tininess that escapes our attention no less than the small size it possessed before being born.” ?°? “Thus, not only

296 THE SCIENTISTS PHILOSOPHY souls but also animals cannot be generated and cannot perish: they are only developed, enveloped, clothed, stripped, and transformed; souls never leave their whole body.” ??? In nature, there was neither true birth nor true death. Leibniz undoubtedly drew upon Leeuwenhoek’s discovery, but the development of his thought owed it nothing essential. Thus, Leibniz was able to write: “I would not venture to assert that the creatures M. Leeuwenhoek made visible in semen are precisely what I have in mind; but neither would I venture to assert that they are not.” ?*4 For if the philosopher could not accept that the fate of his doctrine should be bound to a scientific discovery that might prove false,?°* he could only welcome the success of a discovery that fitted so well with his thought. In fact, we shall see that the success of Leibniz’s ideas would be assured in large measure by opposition to the preexistence of germs rather than through agreement with it. And the originality of this system of thought, whose influence was considerable, consisted not least in its having assumed

a theory grounded in a rigorously static vision of the world in order to use it as the basis for a dynamic conception of nature. Insofar as the monad is a principle of energy bound to an organic unity, and insofar as preestablished harmony includes, not only existent beings, but also possible beings that we do not know, the genius of Leibniz anticipated the future, undermined the concept of immutability,?°° and went far beyond the philosophy of his time. Nonetheless, the doctrine of the preexistence of germs still reigned peacefully, or nearly so. Most of the old scientists converted to it in order to be in step with the times, and the young adopted it quite naturally upon beginning their careers. In 1701, Johann Gottfried Berger, professor at Wittemberg and physician to the king of Poland and the elector of Saxony, conceded to the authority of Swammerdam and Malebranche and accepted ovist preexistence, which had the advantage of doing away with all the agents, “forms, principles,

| architects, wise and learned artisans, to which people had had recourse,’ 7?’ and thus allowed one to remain faithful to mechanism. In 1708, Jean Palfyn took his cue especially from Fontenelle;??* Martin Lister in 1709,” then Prancesco-Maria Nigrisoli and Philippe Verheyen in 1712,7°° in practice confused ovism with preexistence in an indiscriminate approbation. In 1716, Eustache Marcot also neglected to distinguish between them. He did not even think to discuss them: it was established science for him.?®! John Ray saw in them “one of the fairest discoveries in modern physics, but one that should

have been made thousands of years ago, if people had known how to reason and to consult nature herself.” 7°? In the same fashion, Daniel Le Clerc in 1715 had not felt the need to defend preexistence, which was sufficiently

The Preexistence of Germs 297 established by the consensus of “modern philosophers”; he merely wondered

if the development of the germ at the proper moment took place “through the effect only of the laws of motion set up by the Creator at the beginning of time,” or if it were not required, rather, to assume for the development itself a direct intervention by God.*° This question clearly marked yet another step backwards for mechanism, similar to the one taken by Bayle.

Despite Leibniz'’s authority, reinforced after 1708 by that of Hermann Boerhaave,’°* vermist preexistence boasted fewer followers, save perhaps in

England, where George Cheyne among others had adopted it.?® Certain theologians gave it their approval, judging that it was “against the analogy of faith and mysteries to suppose that God would have placed germs inside of women.” °° Nonetheless, in its panspermist form, preexistence had to contend with a strong attack emanating from the physician Pierre Ango of Caen. The controversy had begun in 1693 with a thesis sustained by the bachelier Pierre Le Saulx under the direction of Professor Le Court on the question “An in vermium curatione mercurius?” [Is mercury a curative for worms?], a thesis in which Le Court declared himself a partisan of animalculi. In 1701, his colleague Mézerey adopted the same position in a thesis in which vermist preexistence found backing in the authority of Paracelsus: “An homo sit microcosmus?” [Might man be a microcosm?]. At the end of 1705, Le Court returned to the attack with a thesis on the subject “An homo a verme?” [Does man come from a worm?], which explained how germs swallowed by man became spermatic animalculi through maturation in the testicles and then passed into the egg at the moment of conception. Teratisms came from a foreign germ introduced by mistake. Before being swallowed by man, the germs were above all in certain plants, whose forms suggested afhnities with man, and that clearly fostered fecundity, such as mandrake and lungwort. (This reminder of the theory of signatures shows how lively the influence of chemical medicine still was, and to what extent this influence was tied, at least in Caen, to the success of panspermia.) This time, however, Le Court found an adversary in the person of his colleague Jean-Frangois Callard de la Ducquerie, who sponsored a thesis in January 1706, in which panspermia was treated very badly. Le Court rejoined, then Pierre Ango entered the fray in 1711 with a thesis asking “An homo a vermibus?” [Does man come from worms?], which defended the mingling of the two semens against a theory of preexistence whose consequences were absurd and that was based upon highly debatable microscopic examinations. Leeuwenhoek found himself referred to in passing as “the ridiculous Batavian.” After the thesis had circulated in print, Le

298 THE SCIENTISTS PHILOSOPHY _ Court replied with a heated pamphlet, Curtius Angotio suo [Le Court to his Ango], which drew him a Responsio in which Ango, while lowering his tone a bit, maintained his position and backed up his critiques, which were not without merit.*°” Echoes of the quarrel showed up in the Journal des Savants in 1712, which naturally sided with Le Court and preexistence.2® For by this time, it was agreed that preexistence had been established, according to the formula of James Keill, “by reason and experiment.” 7° As far as procreation was concerned, however, 1723 was a bit late for Pierre Noguez to be translating Keill’s Anatomy, which sided with spermatozoa. As

we have seen, the explanation of generation through spermatic animalculi was slowly succumbing to the problems that the preexistence of germs created for it. Now Antonio Vallisneri, the most careful critic of animalculism, was also the strongest defender of preexistence, and the scrupulous analysis he made deserves our brief attention. For he was not unaware that the doctrine “seems improbable to some, ridiculous to others, and to still others the most thorny and most difficult to conceive of.”””° But what could be put in its place? Mechanism was manifestly inadequate. After all, only three motive principles were known in mechanics: gravity, elasticity, and fermentation, and fermentation alone could be brought to bear here; but no trace of it was to be found and besides, the motions it produced, “being by nature unintelligent and blind, will never be able to create an organic body, which requires the greatest foresight, the greatest knowledge, and the greatest dexterity.” ?”! Could one assume, then, that these motions were guided by a plastic force? This explanation, suggested by Henry More, might seduce “the Platonists, the chemists, the Kabbalists, and all those who find charm and worth only in mysterious philosophies.” But it was incomprehensible, it explained nothing, and Vallisneri deemed himself “authorized, along with the best philosophers of the age, to reject it and to detest it as a refuge and digest of ignorance.” ?”?

| None of this was very new, but Vallisneri had more to say. Might one not believe that God, in giving motion to matter, imprinted on the motion a certain harmony whose effects were prolonged under our eyes? This harmony, replied Vallisneri, might explain the ordinary effects of motion, but not the formation of an organic body. “One will perhaps maintain that in this force

imprinted [on matter], there is a certain method that remains infallible in itself, even though it be unknown to us; that we must not, with our ideas, assign limits and rules to this force.” Then one had to be silent, for one could speak only of what one conceived clearly. “One can understand that nature made the heart and the brain in order to separate certain fluids destined to

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give movement to the entire mechanism . . . ; at least, this is all that we can conceive clearly and distinctly in the use of these organs.” But to assign to the fluids filtered in the genital organs the power to make a living being was to resemble those who, “seeing that the brain is the seat of the internal senses and

the intellectual soul, wear themselves out trying to find in the circulation of animal spirits, in the pulsations of the meninges or the fibers of the oval center, the manner in which imagination, judgment, and discourse are produced. Did this mean that mechanism could produce a living being, and that our minds were simply incapable of understanding how? Vallisneri seems to start out on this path, which would necessarily lead him to assert that human reason had no grasp upon the world: “I concede,” he writes, “that we neither can nor should look for the kingdom of nature in our ideas.” But this conclusion remained purely formal. Vallisneri’s thought was still too rationalistic, even too Cartesian, to accept a purely subjective conception of science: “Who will maintain,” he continues, “that I am not to draw from my ideas the rules for everything I affirm or deny, and that I do not have the right—I who refuse to affirm or deny anything that I do not conceive clearly and distinctly —to deny the formation of animals through mechanics, given that I do not conceive the slightest trace of the animal in all the laws of mechanics?” ’’”* The strength of this negation, moreover, was not confined to what lay within a human construct or a system of knowledge valid only for man. For Vallisneri, as for Descartes, it was God who allowed the human mind to get outside itself and to affirm that the universe was indeed what man saw it to be. For, even if we assumed in nature laws unknown to us, we knew at least that these laws, set up by God, bore the mark of the divine attributes. God could not do anything contradictory to His own wisdom, immutability, or other qualities. These unknown laws “must therefore be necessary, general, simple, and constant.” Now, an examination of facts relative to the generation of animals did not allow us to recognize these characteristics in it. It showed only infinite diversity and extreme complexity. It was not then the laws of mechanics, known or unknown, that assured the formation of living beings. What remained was recourse to God Himself. But God did not interfere in the here and now, for it would then be impossible to understand the permanence of species and the constancy of the laws of development.?”4 Accordingly, the only plausible explanation was the preexistence of germs, against which no serious argument could be mounted.’” It is easy to see how Vallisneri was torn between contradictory impulses. Along with all the naturalists of his time, he was struck by the infinite diver-

300 THE SCIENTISTS’ PHILOSOPHY sity of beings. But he remained convinced of the constancy and uniformity of the laws of nature as a reflection of divine immutability. Thus he ended up by distinguishing in Creation, so to speak, what was related to God’s freedom and what was related to His wisdom. God had created a multitude of diverse beings, with an abundance and variety that defeated our understanding. Then he placed these created beings under the simple and constant laws of mechanism, laws accessible to our intelligence. Vallisneri could therefore affirm that the theory of preexistent germs was “in the end the most suitable to the infinite power and wisdom of God.”?76 On the level of knowledge, the theory recognized the impossibility of the human mind comprehending

the origin of things, which escaped us because it resided in God. But the theory retained for man the power of knowing the laws regulating the workings of natural facts and preserved the mechanical character of those laws. In this way, human reason maintained its grasp on nature. By excluding the formation of living beings from nature, however, Vallisneri placed himself in the tradition of Boyle and Perrault. It should come as no surprise, therefore,

to learn that among the reasons that had persuaded him to embrace preexistence, we find the authority of Saint Augustine. Vallisneri had, in fact, read Father Jacinto Tonti’s Augustiniana de rerum creatione sententia, in which

he had seen that the Augustinian ideas were in perfect agreement with the discoveries of Leeuwenhoek and Redi.’”” As for knowing whether God had originally created souls along with the germs, or whether He created them at the time of development, this was a very abstruse question, on which Vallisneri refused to take sides, despite the pleas of Leibniz and Bourguet.?”® From the strictly scientific point of view, Vallisneri provided nothing more,

in sum, than a very clear analysis of the question at hand. The interest of his contribution lies above all in the general reflections he was led to on the knowledge of nature. In particular, he had not paid particular attention to the question of the development of the preexistent germ. Now, this question remained in the end very obscure, because it was difficult to imagine that the germ grew without an enlargement of its solid substance through the simple introduction of a fluid that distended the already existing parts. To Louis Bourguet, a friend of Vallisneri’s and disciple of Leibniz’s, goes the merit of having closely examined this problem, in his Lettres philosophiques of 1729. The mere fact of his having devoted himself to the resolution of this difficulty points, moreover, to a mentality different from the one we have

been observing. Indeed, although he for the most part shared the ideas of his time, even fundamentally, Bourguet was no less eager to leave the mecha-

The Preexistence of Germs 301

nistic activity of nature undisturbed. The organization of living beings, according to him, could not be understood except through preexistent germs. The “mold” theory, Cudworth’s “plastic natures,” and Hartsoeker's “directive intelligence” were none of them able to satisfy him.””? Still, preexistent germs

did not explain everything. Bourguet approached the study of generation in an unusual fashion, indicative of his mind-set: through the examination of the phenomena of crystallization, in which an organization of matter— admittedly summary, but highly regular—was obtained through purely mechanical means, thanks to the “ordained shapes of the molecules of salts and of crystal,” which could “reasonably be attributed only to the divine Wisdom that formed them in such fashion from the outset.” *°° From there, Bourguet went on to the formation of shells, which Réaumur had carefully observed,

a formation that turned out to be as mechanical as that of stalactites. But what was involved was a “mechanics that I call organic, because it is effected by means of an organized body, without which it would not exist.” 7°? This distinction between the mechanics of crude matter and “organic mechanics” was very important. It immediately led Bourguet to establish a difference between the growth of hair and nails, effected “through the addition of a matter laid down in levels, as an outside,” in the fashion of crystals, and the growth of living parts, effected “through the addition of new molecules throughout the inside simultaneously,” or, as the Scholastics said, by “intussusception.” 7°? What Bourguet had rediscovered, then, was a very old distinction, but one that had been forgotten. It was therefore no longer possible to conceive of the growth of the preexistent germ as a mere extension of tissues. The molecules that came to join the solid parts, in order to make them grow, had to be suited to this role. One had therefore to admit that there existed “in the bones, nerves, membranes, muscles, etc., organs so artistically made that"they are naturally disposed to transform the fluids they receive from the general mass of blood, and to make

them their own through a mechanism that, while the same in all, becomes particular in each.” 78? What Bourguet was rediscovering was the “third coc-

tion” of the old authors, the one that adapted the blood to the nourishment of the different parts of the body and that functioned thanks to a “coctive” or “assimilative faculty” residing in the organs to be nourished. ‘To replace the outmoded “faculties,” Bourguet had to borrow the more geometrical image of the “mold” from his mechanistic Epicurean opponents. He therefore accepted that “molds are found in all the parts of the human body” ?* in which, starting with molecules of chyle, they in some way created living matter. It

302 THE SCIENTISTS PHILOSOPHY was not thus mistaken to say that “the Organic produces the organic, 7*° provided, however, that one specified that “the organic mechanism can function only in an already organized body.” *°°

Bourguet could not, then, do without preexistent germs, for it was not possible to see “where to find the mold for the entire body of the fetus.” 78” Conversely, however, the germ could not develop on its own, for in its primi-

tive state it lacked movement and the power to serve as a “mold” for the , nutritive molecules. Here was where the parental seeds entered in, keeping in mind that, according to Bourguet, the female provided both the egg containing the preexistent embryo and a semen that mingled with that of the male. Each of these semina was “a highly spirituous liquid, which is simply an extract of the parts of the animal that transmits it.” °° The mingling of these two “quintessences” communicated vital movement to the embryo and at the same time provided it with molecules already assimilated in the organism of the parents by the “molds” of each part. These molecules incorporated themselves into the preexistent parts of the embryo, explaining the phenomena of

| heredity and hybridization. Once the first development had been completed, the embryo fell into the womb and derived nourishment from the maternal blood, whose final assimilation it could henceforth undertake. Clearly, while remaining faithful to the concept of the preexistence of germs, Bourguet had reintroduced ideas abandoned by official science: the

dual seed, the theory of the third coction, modernized in the concept of molds, and the old Hippocratic defluxus. In actuality, he had borrowed all these ideas from the partisans of integral mechanism, whom he simultaneously condemned as “naturalists,” “materialists,” and “Spinozists.” *®° The preexistence of the living being, prior to all mechanics, allowed him to distinguish an “organic mechanics,” infinitely more complex than the mechanics of the physicists, although basically of the same nature. He thus rid biology

of an abstract analogy that had been paralyzing it. On all these points and especially in his simultaneous championing of preexistence and the necessary role of a natural mechanism at work, Bourguet was openly following Leibniz, even flattering himself with having rendered the thought “of that celebrated

philosopher” more intelligible.??° It was also to Leibniz, above all, that he owed his final definition of organic mechanism: Organic mechanism is nothing other than the combination of the movement of an infinite number of etherean, aerean, aqueous, oleaginous, saline, terrestrial, and other

, molecules, made suitable for particular systems that have been determined from the

The Preexistence of Germs 303 outset by the supreme Wisdom, and each of which is united with a single and domi-

nant activity or monad, to which the molecules entering into its system become subordinated.?”!

This copious definition upheld vital mechanism along with its dynamics, while at the same time subordinating it to an organic unity that assured its regularity and originality. Like Leibniz, Bourguet gave this organic unity a directly divine origin and made a preexistent germ of it. In all his other ideas, however, he served as an unknowing link between the successors of Lamy, whom he was contending with, and Buffon, who would be able to put his investigations to effective use. Nonetheless, Bourguet’s book received little attention, and the theory of preexistence remained unchanged. In 1741, Gilles-Auguste Bazin was content simply to illustrate the classic proof by way of the divisibility of matter with a few new examples and to add an extra proof founded on the extreme po-

rosity of matter. Did “the famous Newton” not say “that there is perhaps not a cubic inch of matter in the entire universe?” 2?” The infinite smallness

of germs thus became easy to conceive, even for those who, slaves to their imaginations, could subject themselves to the light of reason alone. If the problem of generation in itself no longer fascinated the scientific world, however, it could not remain a matter of indifference to entomologists, and it is with Réaumur that this chapter ends. Réaumur duplicated Swammerdam’s observations and concluded like him that insects did not undergo true metamorphoses: the chrysalis was “a genuine butterfly, one that is in some way swathed. One generally finds in it all the parts of the butterfly — the wings, the legs, the antennae, the pump, etc.” *°? One found the eggs to be laid by the butterfly in the caterpillar itself.2°* However, the caterpillar was not simply a disguised butterfly: it had sixteen legs, of which ten would become atrophied in the chrysalis, whereas the six others served as sheaths for the six legs of the butterfly. Moreover, the caterpillar and the butterfly did not take the same nourishment. Was the caterpillar’s stomach, “filled and swollen

with rather badly crushed leaves that it was supposed to digest, the same stomach that will later on need to contain and digest merely a little honeyed liquid?” ?”° This was not very plausible, but exact observations were lacking. What was known was that in the chrysalis there were “parts that were not perceptible” and that “develop,” since “in the butterfly the space of the abdomen is occupied by parts that were not visible in the caterpillar,” whereas the parts of the caterpillar ceased being visible in the chrysalis.7°° Here, Réaumur

304 THE SCIENTISTS’ PHILOSOPHY went beyond what observation provided, by assuming that the organs of the butterfly already existed, although invisible, in the caterpillar. His conception of life kept him absolutely from envisaging the possibility of the formation of new tissues and organs. Unable even to think of it, he accepted the existence of invisible parts, a remarkable thing in this rigorous observer.

The reason was that Réaumur could not abandon the preexistence of germs. Ihis was not only because “today . . . most philosophers refuse to accept any true productions of plants or animals,” but above all because “even if there were true productions . . . as other philosophers claim, we would have to give up on explaining how they are effected.” For, If one attempts to derive clear ideas of the first formation of some organized bodies, one soon realizes that the force of our reasoning, and the extent of knowledge we are permitted to have, cannot possibly bring us there; we must begin with the development and growth of beings already formed, without attempting to go further back.?9”

As in the case of Vallisneri, we can only wonder if the preexistence of germs was not a veil cast over an inaccessible reality, a convenient hypothesis whose only function was to allow men to construct a science cut to their capacities. This text, dating from 1734, invites us to believe so. Preformation was certain, but it was of another, uniquely scientific order. Preexistence had of necessity a metaphysical import. It involved the relationships between man and nature, not objective reality.

Réaumur does not seem, however, to have stayed with this attitude. As early as the second volume of his Mémoires, published in 1736, he made public the results of his investigations into the development of chrysalids and his observation that this development was accelerated by heat and slowed down

by cold: ,

There are, then, very long stretches of time during which one stops the perceptible growth of the little animal without killing it. If one meditates deeply on this idea, and if one draws all the consequences that it can furnish, it will appear to favor heavily the belief of those who, to console us for the impossibility we perceive in explaining the first formation of organized beings, would have it that they have existed since the world has been the world, and that they develop only when circumstances foster their doing so.?78

If, in fact, an insect could remain several months in the egg without growing, we can conceive that there were times when this insect, prodigiously smaller than it is in the egg, was contained in an envelope of an indeterminable smallness, where it lived without expanding or developing, and that it may have been contained therein

The Preexistence of Germs 305 for century upon century without perceptible growth. Plants are apt to dispose us less to revolt against this somewhat terrifying idea.???

Indeed, a seed containing a tree could germinate after twenty years. What was true for the plant or the insect was equally so for the chick: a lacquered ege would stay good for a long time and could then be incubated.> This all rendered more plausible the preexistence of germs, which would thus no longer merely serve “to console us.” Another observation was to come along later on to confirm this likelihood: the very important discovery of the parthenogenesis of aphids. Réaumur had raised the problem in 1737: the male aphid was not to be found, and one saw no coupling among aphids. But he had not been able to succeed in perform-

ing a most simple and decisive experiment: to isolate an aphid at birth and see whether it produced offspring. All of the aphids observed by Réaumur had died before reaching reproductive maturity.*” It is known that this observation was successfully made first by Charles Bonnet in 1740,° then by Bazin, Trembley, and Lyonet. Réaumur duplicated it himself before mentioning it in his Mémozires.°°> The fact, then, was solidly established. But how was one to interpret it? Was one to assume that aphids were hermaphroditic,

and that a kind of internal fertilization took place in them? “The absolute necessity of this internal operation is not, however, self-evident; it could be supported only by analogy; but the most accurate analogy is found wanting with respect to the creatures in question.” 3°4 Here, the preexistence of germs provided a perfectly natural explanation. No doubt Réaumur was reminded, in passing, of its practical usefulness: “Either we must not reason about procreation or we must limit ourselves to a consideration of the embryo at the point at which it has become capable of beginning its growth.” *°° But the

most obvious incapacity here was not that of the human mind to conceive of the formation of an animal; it was that of the creature itself to form its like: “We cannot find the apparatus necessary for producing such astonishing machines; the most intelligent of created beings would not succeed, even though grappling with it continually. So great a work cannot have been done but by the intelligence par excellence.” °° This said, the problem was simply

one of knowing whether the preexistent germ was in the female or in the male. “Scientists are divided regarding these two possibilities, but they have to agree in recognizing that self-fertilizing animals have inside them germs, embryos, that are one day to become their like.” °°” The generation of aphids thus became perfectly clear:

306 THE SCIENTISTS’ PHILOSOPHY It is perfectly natural to think that . . . embryos develop in the body of the aphid as soon as it begins to grow; and this seems to be proven by the presence of well-formed fetuses in aphids still far from the end point of their growth, and before they begin

their transformation. It seems to me that far from finding it difficult to grant that the generation of aphids can occur in so simple a fashion, one should find awkward only the fact that for the generation of other animals a more complicated mode was established by Him who cannot fail to choose the most perfect and fitting means.°8

For to suppose that God willed distinction by sex “to dispose animals of a same species to love to be together and to seek each other out would be to assign a moral reason,” and one that would be valid only for gregarious animals.>°? We had therefore to resign ourselves to ignorance as to why the sexes were distinguished in this way, but we might believe, given the example of the aphids, that this distinction was not physically necessary. The preexistence of germs, which made the distinction useless, thus found itself confirmed.*”° By 1749, however, Réaumur was perhaps less convinced of the objective reality of preexistent germs. He knew and rejected the new theories attempt-

ing to resuscitate epigenesis. He rejected them because he considered them incomprehensible. He could not, however, remain insensitive to the import of certain observations, in particular those of Maupertuis on the phenomena of heredity and hybridization.*"' Nonetheless, he remained faithful to preexistence, but it was above all, as at the outset, because it was the only doctrine that accommodated our weakness: “Let us not hope, then, to explain the first formation of an animal: if it pleased the Supreme Being that germs should be formed daily, of which there is reason to doubt, we must despair of knowing the means that He employs for this.” No doubt we could still learn much about reproduction, but “any man who has sufficiently meditated on the nature of a germ or the nature of an animal will not undertake to explain its formation; it has not been granted us to be able to go back that far.” >” Descartes “presumed less of the powers of his genius when he undertook to explain the formation of the universe, than when he attempted to explain that of man.” 3%

Thus, the ambiguity persisted to the very end. The preexistence of germs was required by the inadequacy of our minds to conceive of the natural formation of an animal or, what came down to the same thing for Réaumur as for Vallisneri and Perrault, by the incapacity of nature to form an animal.

It was God who created the germs. No doubt He could form them as the need arose, but the idea of this permanent miracle was repugnant to minds that could not entirely resign themselves to considering nature as subject to

The Preexistence of Germs 307

the arbitrary quality of a will that respected no order. Creation belonged to God, development was part of nature. For Perrault and Vallisneri, development had not raised serious difficulties, and the laws constituting the order of nature remained accessible to man. For Réaumur, this was no longer the case, for he, like Bourguet, no longer believed that preexistence resolved all problems: “Even simple developments present only too many difficulties to be resolved.” 3!4 Fontenelle, too, had noted as much: “Although the theory of the animal already formed in the egg makes its generation conceivable, it still does not keep it from being most wondrous.” *!° With respect to the formation of living beings, the preexistence of germs made up for the incapacity of nature as much as for that of our minds. But development itself, although part of nature, escaped our understanding almost as completely. Bourguet had attributed development to an “organic mechanism,” of which he was unable to give a clear idea. Everyone, along with Bourguet, would admit that development was produced by a mechanism, that this mechanism was subject to constant laws, and that nature was not a succession of miracles. But this conviction did not rest upon the observation and understanding of phenomena: it was founded only upon a certain image of God. The order of nature was no longer apparent to the scientist. By virtue of its very character as a metaphysical certainty, the theory of preexistent germs was beyond all experimental verification. Its success at a time

when everyone was proclaiming fealty to experimentation would be highly paradoxical if this metaphysical “system” had not had as its exact consequence the preservation of science from all temptation to construct a physical “system” to explain the generation of animals. The human mind, convinced of its own inadequacy, “consoled itself,” in Réaumur’s words, and in order to deny

responsibility for this inadequacy, assigned it to nature. Henceforth, it was freed to devote itself to its passion for observation, without mental reservation and without any concern for rational constructs. If the facts could prove nothing, however, they were nonetheless going to raise grave problems. These problems, and their consequences, are examined in the following chapter.

Problems with Preexistence

BECAUSE OF ITS evident metaphysical character, the preexistence of germs had at first met with philosophical objections. On the scientific level it was from the outset to encounter an objection that should have been serious: its inability to explain the phenomena of heredity and hybridization. In fact—as will be seen—the latter difficulty was never taken very seriously. On the other hand, more attentive observation of nature was to uncover new facts and revive ancient questions. The study of partial regenerations and of teratisms put partisans of preexistence and of biological mechanism in an embarrassing position. Most of them clung to their convictions, producing the odd spectacle of observers who preferred to take refuge in the most bizarre and groundless hypotheses rather than give up preexistent germs, as if this system, which justified their not going beyond the facts, were dearer to them than the facts themselves. A few thinkers, however, rejected the preexistence of germs and looked to the past for theories that in fact would lay the groundwork for the future. This chapter concludes with an examination of these early signs of dissidence.

I

Heredity and Hybrids

The first problem inherent in, and indeed raised by, the preexistence of germs was that of heredity. Since parents were no longer responsible for the formation of beings that had existed since the beginning of time, how could

Problems with Preexistence 309

their children possibly resemble them? Claude Perrault raised the issue as early as 1680 and resolved it by recourse to the maternal imagination: For it is not difficult to conceive that the form of an extremely small body could be changed by a simple modification, and by what is capable of enlarging it in different ways and restructuring it according to the different movements given to the matter used for growth, which, being diversely governed by the imagination, can easily determine that a thing exists in a particular fashion, even if it does not have the power to give it being.

Perrault, who believed in the inheritance of acquired characteristics (muti-

lations, for example), likewise explained them by maternal imagination, which had the power to direct or not to direct the nutritive fluid towards some part of the embryo: a part deprived of nourishment would not develop.” This explanation, which eliminated all physical intervention on the father’s part, ran up against the traditional argument of resemblance to grandparents, whom the mother might not have known. It was therefore necessary to accept the common notion that the grandparents had given dispositions [i.e., tendencies] to their offspring, so that the parts engendered in them for the preparation of the generative matter transmit to the particles of this matter particular configurations and aptitudes to be moved in a manner proper for producing one shape rather than another in the parts of the bodies engendered by means of this matter.

In order to adapt this explanation to preexistent germs, all that was needed

was to substitute nutritive matter for generative matter? All this remained rather obscure, and there is no need to underscore the dilemmas of a theory in which animism was summoned to the aid of a tottering mechanism. The phenomena of hybridization engaged the problem of heredity in far clearer terms and risked creating still greater difficulties. It was from these phenomena, however, that Leeuwenhoek had thought he could borrow a decisive argument in favor of preexistence in the spermatozoon. He had noticed, in fact, that by crossing white domestic doe rabbits with wild buck rabbits, which were smaller and gray, one always obtained small, gray offspring that never displayed either the size or the long ears of their mothers and kept the wild nature.* The observation was accurate, grayness being in this instance a dominant characteristic. The generalization that Leeuwenhoek drew from it was obviously more risky and did not seem convincing to Denis van der Sterre, for whom it was intended and who believed in preexistence in the egg. For he could not understand how a fully formed animal, like the spermatic

310 THE SCIENTISTS PHILOSOPHY animalculus, could be modified, whereas the rudiments contained in the egg could very well be transformed under the influence of the paternal leaven.’ In this way, the “equine leaven | fermentum equinus] is what causes growth and extension of the eggs of a jenny into an animal different from either parent, that is to say, a mule.”® The phenomenon was analogous to that of grasses that changed according to the soil.’

It is easy to see that Sterre was not yet very convinced of the fixity of species, and that his notion of the preexistent germ was not as rigorous as that of some of his contemporaries. But it was to be the hallmark of the difficulties raised by heredity that they would force the most determined partisans of complete and preexistent germs to assume a certain plasticity in these terms—what Pierre-Sylvain Régis called the “flexibility of the fetus” in 1690, elaborating as follows: When the male’s seed penetrates into the pores of the eggs, what is to keep us from thinking that it opens them in such a way that they are more disposed to receive matter whose particles resemble the seed of the male than other particles? Which means that the particles entering into the composition of the infant’s body become arranged more or less in the same way as those in the father’s body; which is the true cause of the resemblance between father and son8

Similar “dispositions” assured resemblance to the grandparents and the existence of hybrids.’ This mechanistic yarn was to become the accepted explanation for the phenomena of heredity and hybridization. It possessed, in fact, the double advantage of agreeing with the current notions of corpuscular physics, which saw only pores and particles everywhere, and with the more generally accepted interpretation—at least among the ovists— of fertilization through the aura seminalis, conceived of as a vapor formed of elastic particles, which at the same time extended the parts of the embryo and imparted the vital movement to them. This theory of Régis’s ° had already been

expounded in the Journal des Savants in 1688," and it would thereafter be found everywhere. Pierre Dionis adopted it in 1698,’? apparently finding it adequate for resolving the problem of hybrids.’? Daniel Tauvry was no longer so easily satisfied in 1700, however, and thought that the problem could not be resolved either by the encasement of germs or by panspermia.'* The argument was rehashed at length by Pierre Ango in 1712. His opponent Lecourt, seeking to reconcile Leeuwenhoek and Perrault, had explained resemblance to

the mother by way of the nutritive action that caused the embryo to grow— the classic explanation of the animalculists—and resemblance to the paternal grandfather by way of the action of the father’s imagination upon the sper-

Problems with Preexistence 311

matic animalculi. Ango mocked this somewhat ponderously, but not without good sense, stressing the example of hereditary illnesses and of sterile hybrids and recalling that if species were fixed, nutrition could not modify the form of the germ.’° This amounted to turning against preexistence the static conception of nature of which it was the most perfect expression. The Journal des Savants felt it necessary to point out Ango’s arguments to its readership.’© Unfortunately, Nicolas Andry had nothing better with which to counter them than Sterre’s old answers.!”

With the power of imagination gradually undergoing a loss of credit, there remained only the action of the aura seminalis to assure resemblance or the intervention “of the juices from which the embryo is formed and nourished, and that imprint the same [hereditary] character on the tender body of the infant.” '® This action itself had no explanation, as Pierre Barrére noted in 1741.” The science of the period, however, was not really concerned with questions of heredity and hybridization. The answers it provided remained purely theoretical. The great problem in its eyes was the formation of the living being, considered as an isolated individual without essential relationship to the individuals of the same species that had preceded and begotten it. Descartes had, of course, admitted that particles of the seed destined to constitute the em-

bryo came from the different parts of the parents’ bodies. But, aside from that, he had completely neglected the phenomena of heredity and had construed spontaneous generation as entirely simple and natural, producing an animal through the gathering together of particles scattered in brute matter. This aspect of his theory, which was well suited to the mentality of the time, was alone retained, whether the theory itself was accepted or rejected. The mechanical formation of a living being was, in any case, the emergence of an isolated individual starting from crude brute matter. In truth, mechanism excluded the notion of life, the species that preserved it, and the generation that transmitted it. The partisans of preformation, attempting to preserve the role of the parents, found themselves reduced to simplistic images. Thus, there remained only an individualist conception, so to speak, of generation, a conception that was also found carried to its highest level in the theory of preexistence, in which all living beings— past, present, or yet to be born—were

in reality contemporary with Creation, all independent of one another, set side by side, and with no link among them besides having all issued directly from the hand of God. Preexistence excluded time and all notions of a history of life. Nature was entirely in the present, and the present itself flowed into

_ the eternity of God. Nothing could have been more foreign to this period

3I2 THE SCIENTISTS PHILOSOPHY than the genetic character of Aristotelian form. Thus, the scientists had little trouble in accepting that children owed nothing essential to their parents: God Himself had created them, and if a cause was required for the sterility of hybrids, René-Antoine de Réaumur would seek it in divine wisdom: The author of nature wanted our earth to be populated by a prodigious number of animal species, and he gave it what it needed for that; but he did not want the num} ber of species on earth to rise to infinity. With the passage of time, the earth would not have sufficed to nourish the species of animals for which it had been destined, if new species fit to produce other new species had been able to appear daily.”°

In nature, then, hybrids were merely a disorder, the dangers of which the

Creator limited. Réaumur ended up, however, by thinking that the study of them might finally resolve the debate between the ovists and the animalculists: the inheritance of characteristics in the crossing of different species would show whether the germ came from the father or the mother. He even carried out many experiments in this respect.”’ But the results were never pub-

lished, and in any case this belated idea, prompted perhaps by Pierre-Louis de Maupertuis, no longer tallied with the doctrine of preexistence. This was because, logically, a germ in existence since the beginning of the world had no particular reason to bear a greater resemblance to the one of its parents that had served as its final vehicle. The theory of preexistent germs could no more utilize hybrids than it could explain them. This weakness, long underestimated, was to appear serious after 1745.

II Partial Regenerations and Reproduction Through Cloning

The living machine is not content merely to be born and to die. It lives, and this duration must not be confused with the survival of an inanimate body based uniquely on the cohesion of parts. Each year, living plants have new vegetation. Birds moult, and stags produce new horns. Even with man, hair and nails never stop growing, and baby teeth are replaced by adult teeth. Without going beyond these facts of common observation, the abbé Bourdelot could write in 1681: “This neoterism, or new production of parts, allows us to comprehend the great resourcefulness and fecundity that nature has placed in living bodies; which distinguishes them from artificial machines, which diminish every day.” ?* The formative power of life was, however, going to be placed in evidence by less banal and therefore more striking observations.

Problems with Preexistence 313

On June 12, 1686, the traveler Melchisedech Thévenot presented to the Académie des sciences a green lizard whose tail after having been cut off “seemed, so to speak, to be reborn”: inside of twelve days, it had already grown back in by about two-thirds of a thumb.” On July 3, the gathering saw the lizard again, and its tail had developed considerably.’* Perrault published a dissertation on the subject in 1688.74 After having stated how perplexing the phenomenon was, and how apt to make us realize that physics was merely a conjectural science,”’ he explained that parts that regenerated normally — birds’ feathers, stags’ horns, human teeth—did so on the basis of certain “kinds of seeds” that were in place and ready to be used. In other words, there were germs of teeth just as there were germs of animals, and it was never a question of anything other than “development.” These comments on the formation of teeth were to be confirmed the following year by Joseph Guichard-Duverney.”* However, continued Perrault, “it is difficult to conceive that there are seeds of tail ends.” Luckily, no one was reduced to this hypothesis, for dissection proved that the regenerated tail was not like the old one, but simply cartilaginous material.?” One could therefore believe, according to Perrault, that it was a matter of simple “development” of already existing parts, cartilage from the spinal column and scales from the skin, a development directed by “the power that governs each animal.” For “in this occurrence it is merely a question of modifications in the shape of a thing that is already formed.”*® This simple modification had already required, however, the intervention of a soul, which amounted to an admission that it transcended the forces of mechanics. Perrault’s dissertation evidently did not create much of a stir,” and the green lizard was forgotten. Ten years later, on April 19, 1698, the Académie

| got around to discussing hair that did not grow back on head wounds, and then nails, which, according to some, could grow back on a finger whose last phalange had been amputated. Wilhelm Homberg then asserted that, having removed a crab’s claw, he had seen one almost as large grow back in place of the first. Everyone agreed that the occurrence “seemed rather difficult to explain,” *° but no one pursued it any further. For ordinary phenomena, the

doctrine of special germs lodged in living bodies seemed to be accepted: Giorgio Baglivi reminded his correspondent Andry in 1699 that “teeth remain hidden several years inside the gums, hairs are enclosed for a long time *In the original, “about eight lines,” a line being one-twelfth of a thumb in the old measurements, or .22§ centimeters in modern measurements. Hence two-thirds of a thumb is 1.8 centimeters. — Tr.

314 THE SCIENTISTS’ PHILOSOPHY as if in little packets in their follicles” until the moment when they appeared.” For Etienne-Frangois Geoffroy, in 1704, the fecundity of plants capable of reproducing through layering, proliferation, or cloning, “clearly shows us that each plant is nothing else, inside, than a wondrous tissue of an infinite number of other plants of the same species.” ** This “clear vision” was in reality pure conjecture, but how else was one to explain these awkward phenomena when one was convinced that the plant had to be fully formed in the seed in

order to be able to issue forth from it? On November 16, 1712, Réaumur read the Académie a long report brilliantly confirming the observation advanced by Homberg: when one broke off a leg or part of a leg of a crayfish, that leg or part grew back exactly as it had been. Réaumur’s reflections are of the highest interest, for they show us a powerful intelligence torn between irrefutable facts and the requirements of the mentality of the time, manifested here in all their strength. He began by noting the implausibility of the phenomenon: The better informed one is concerning the structure of each of the parts of the creature’s body, the less one is disposed to believe that its reproduction can occur naturally. An arm, a leg, are designed with no less art than the other parts of the body. The particular formation of one or another of them is scarcely less difficult to comprehend than that of the entire creature. . . . In order to reproduce them, it would seem therefore that nature would have needed to prepare the complicated apparatus that it uses for the formation of the animal; and one does not discover that it has set up anything of the kind to derive the large legs: is there any likelihood, then, they

might be reproduced naturally? 3 |

It must be noted in passing that “the complicated apparatus” set up by “nature” for “the formation of the creature” did not refer just to the reproductive organs, but also to preexistent germs. God alone was active, and it ~ was He who was hidden behind the word nature: this excluded all natural re-

production, that is to say, reproduction solely by means of the forces of the created world. The problem was, then, one of knowing if the phenomenon was “natural” or if it required an “apparatus” created by God. This is proven by what follows in the text. For after having minutely de-

scribed the data, Réaumur takes to regretting that man himself does not possess so useful a gift: “Do we not have cause to complain of nature, which has treated animals that appear so lowly more favorably than us?” Was Providence more concerned about insects than about man? Réaumur, a Christian, dismissed this idea, which might have tempted a deist, and concluded on the contrary that nature “provides us here with a fine opportunity to admire her

Problems with Preexistence 315

foresight.” For the claws of crayfish were very fragile, and often broke in the course of their lives, whereas “we have nothing of the sort to fear.” >4

Let us return to the data. “What most deserves attention is that there grows back on to each leg only the part exactly like the one lost. . . . Nature gives back to the creature only and precisely what it has lost, and gives back all that it has lost.” 3° The site of the break became covered with a membrane that “already contains a part of the leg, very small in truth, but like the one that has been taken away from the crayfish.” *° Such were the facts in need of explanation. But must we undertake to explain how these reproductions occur? At most we might hazard a few conjectures; and what sort of faith can one put in conjectures, when it is a question of accounting for facts whose impossibility clear reasoning has seemed to demonstrate?

Might one propose the formation of new flesh by the nutritive fluid? But where are we to find the cause that divides this new flesh into diverse articulations, forms nerves, muscles, and different tendons out of it? All that we might put forward, the only convenient, and perhaps the only reasonable idea, would be to suppose that each of these tiny legs that we see being born was contained in tiny eggs, and that when a part of the leg is cut off, the same juices that had served to nourish and develop this part are used to develop and bring into existence the kind of tinyleg germ contained in this egg. However convenient this supposition may be, few will find themselves able to accept it. It would require us to assume as well that there is no place in the leg of a crayfish where there is not an egg containing another leg; or, more wondrous still, a part of a leg similar to the one that is there from the place where this egg is situated up to the end of the leg: so that at whatever spot in the leg one might designate, one of these eggs would be found, containing a different part of the leg than the egg a little above or than the one a little below.*”

One would even have to assume several eggs at each spot, for “if one cuts the new leg, another is reborn in the same place.” Moreover, the new leg has its eggs as well: if one breaks it in half, it regenerates the missing part. “In the last analysis, it appears that the reproduction of crayfish legs is a matter into which we can hardly hope to see clearly; besides its specific difficulties, it has all those surrounding the generation of the fetus.” %° Having so powerfully denounced the vertiginous hypotheses suggested by

the assumption of claw germs, was Réaumur about to blame the theory of preexistent germs? Not at all. If there existed a theory that the phenomena of regeneration made improbable, it was that of spermatic worms: The legs, or the leg parts, of crayfish are surely not born from a worm, or a part of a worm... . If the leg is truly produced anew, or if it is born from an egg, why would

316 THE SCIENTISTS’ PHILOSOPHY the whole animal not be produced anew, or why would it not be born from an egg? In a word, the leg or leg part . . . apparently does not come from a leg or leg part that has had movement since the beginning of the world: why, then, would one wish to consider the entire crayfish born from a creature that has been moving since the beginning of the world? The one is no more necessary than the other.°?

The final argument is unexpected, but logical. The hypothesis of preexistent leg germs was manifestly absurd. But any other hypothesis was inconceivable. For lack of anything better, one thus had faithfully to look to germs for regenerations as well as for generation. As for Fontenelle, he was still more skeptical than Réaumur: if generation was a remarkable phenomenon, regeneration of parts was “a second marvel of a different order from the first, and one the egg theory cannot cover.’ #° But he had nothing to put in its place. Hence, the regeneration of crayfish legs did not succeed in undermining the credit of preexistent germs. It did, however, bring them a supporter in the person of Nicolas Hartsoeker, as we shall see. Jean Marchant’s observations on a three-tailed lizard, presented to the Académie in 1718,*! added nothing to those of Perrault and were just as quietly received. The crayfish matter had had no sequel, and no doubt regeneration had been forgotten when the affair of Abraham Trembley’s polyp exploded in 1741. This strange, minute animal, which Trembley had discovered in 1740,

reproduced in the manner of plants: the offspring was formed by emerging progressively from the body of the adult, like a sprout coming out of a branch.*? Informed of this, Réaumur asked Trembley to carry his research further: “One might suspect that you have not observed everything. If the offspring, or the egg, that the polyp has just given birth to attached itself to the body of the polyp, or the polyp itself attached it the way crayfish attach their eggs beneath their tails, it could appear united with the body of the mother, and when it grew there, it might seem to be merely a sprout like that of plants.” 4? Réaumur was obviously seeking to usher the generation of the polyp back into the category of known phenomena. Trembley was obliged to reply that Réaumutr’s version did not seem possible to him.“ Most extraordinary of all, however, was the regenerative power of the polyp. If it was cut in two, each half became a complete animal. If cut in four, in eight, in sixteen, one obtained four, eight, sixteen complete polyps. The phenomenon was simply incredible. “I found it difficult to believe my eyes,” wrote Réaumur, “and it is a fact that I cannot become accustomed to seeing, after having seen it and seen it again a hundred and a hundred times.” *° It was “the strangest and most perplexing novelty that has ever been offered to those

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who study nature.” 4° And thus, this discovery “constitutes news much discussed at court and in the city.” 4” Then it was noticed that other species possessed the same capacity: Charles Bonnet, Pierre Lyonet, and Father Angelo Mazzoleni, an Oratorian in Rome, discovered it among other aquatic worms;

Guettard, Bernard de Jussieu, and a physician in La Rochelle, Gérard de Villars, observed it in starfish; Bonnet and Réaumur himself found it in certain earthworms.*® All of these animals were fragile and broke easily, or they might often be partially eaten. This was why this property “was due them by preference.” 4? All that remained was to understand the phenomenon. Now, if the regeneration of crayfish legs was as refractory to explanation as the formation of an animal, “it seems to me at present every bit as difficult,” noted Réaumur, “to explain how an animal divided in two becomes two animals.” ° That these regenerations were analogous to generation itself Réaumur did not doubt. He even thought that “these new productions will perhaps serve to provide us with enlightenment concerning this mystery of nature.”*' But that it might be necessary to give up on germs seems not to have occurred to him. In the regeneration of the polyp, “developments of germs” were “occurring before our eyes.” °? Réaumur seems to have forgotten all the difficulties he had perceived militating against this hypothesis in the case of the crayfish legs, and that reappeared here with greater force than ever. The problem that held his attention was of a completely different order. Réaumur, “through an internal feeling, and even a spirit of justice of sorts,” believed that animals possessed souls; But are there divisible souls? What kinds of souls would be those that, like bodies, could be cut into pieces and then would reconstitute themselves as the same? If the animal soul has a designated site, where it resides in the manner of souls, if this place is in the head, are we to imagine that each piece of the body is not only provided at its end with a head germ, but that moreover this head germ contains a soul germ; that is to say, that to the germ suited to become a head is attached a soul that will be capable of exercising its functions only when the head germ has developed, and has acquired the power to perform the functions of a head, and it has become the head of the animal? >3

The question was insoluble, Réaumur concluded, for physics could not enlighten us concerning “beings that are neither body nor matter.” But the question itself could be raised only because of the highly Cartesian manner, so to speak, in which Réaumur conceived of the animal soul: a spiritual soul dwelling in a living mechanism “like a pilot in his ship,” according to the old formula; a soul that directed a body to which it remained foreign. For bio-

3188 THE SCIENTISTS PHILOSOPHY logical mechanism did not permit any other conception of the souls of animals. And precisely what the regeneration of the polyp cast light on was the autonomous activity of living matter, its power to adapt itself to unexpected circumstances, to direct its own development. All these were characteristics of life for which mechanism was powerless to account. The impossibility of explaining the regeneration of the polyp through preexistent germs was merely a particular instance of this inadequacy in mechanism. And, finally, Réaumur remained faithful to the preexistence of germs because all the elements of mechanistic thought—the absolute passivity of nature, fixity of species, the radical distinction between matter and soul, whatever might be the form of activity understood under this name—had become the very foundations of his thought, and he could in no way give them up. Whether a genuine reality or a convenient system, preexistence was indispensable to Réaumutr, as to his contemporaries, who preferred ignorance to the abandonment of clear ideas. Other minds would be needed to look for other systems.

II] “Monstrous Births” (Teratisms)

However important the problems raised by the phenomena of heredity and partial regeneration, the most serious difficulty that the theory of the preexistence of germs was to encounter remained the question of teratisms [monstrous fetal disorders]. We have seen that the old physicians had always been interested in individuals born with teratoid characteristics, all the more

so in that the absence of a critical mentality made these beings that much more extraordinary. But we have also seen that the idea of an active nature susceptible to error allowed the Creator to be relieved of responsibility. Besides, teratisms were often attributed to interference by the devil.*4 Intellectual evo-

lution was to destroy this double screen placed between God and teratisms. Mechanistic nature, purely passive, produced nothing in itself; the “God of philosophers and scientists,” an all-powerful Creator, could not see His intentions thwarted by some demoniacal power. Teratisms existed, therefore, only by His order, and Jean-Baptiste Duhamel recalled in 1663 that this was one of the favorite arguments of the Epicureans against Providence, which he refuted by maintaining that God allowed free play to natural causes, and that _ in any case “monstrous” births were there to make us more attentive to the perfection of normal beings.*?

| Problems with Preexistence 319 The problem of teratisms, then, was not new: it was as old as the problem of evil, of which it was merely one aspect. Starting in 1670, however, the problem took on particular importance, if only because teratisms were the object of increasingly attentive study. The taste for mzrabilia had certainly not died out (examples of it drawn from journals and publications of learned societies have been given above). The progress of the critical spirit, however, ruled out discourse on prodigies that one had not seen. The Académie itself examined the teratisms sent to it or presented before it; anatomists dissected them carefully; drawings of them were done directly from nature. Starting in 1675, it would be the most careful scientists — Mariotte, Dodart, and then Duverney, Méry, Lémery, Littre, and their successors—who presented and studied prodigies. They presented so many that Fontenelle eventually expressed a certain lassitude, in 1712, judging that the history of teratisms was “endless and not very enlightening.” °° Whatever one may think of this premature judgment, it is understandable that the nineteenth-century founder of scientific teratology, Isidore Geoffroy Saint-Hilaire, should have spoken of this period as “positive, because, he said, “the importance of observation began to be understood, and a great number of facts were collected with care and exactness.” °”

If the facts were better known, the explanation was none the easier. The preexistence of germs utterly complicated things: if God had directly created all living beings, He must also have directly created teratisms. The consequence seemed so necessary that several scientists, because of it, rejected preexistence at a time when it was still possible to do so. Thus the reaction of Dionis in 1698, Tauvry in 1700, Besse in 1702.’* Later, opponents would be fewer, and G. V. Hartmann, who took up the argument again in 1733, cuts a lonely figure.”? The stance of all these scientists rested on a spontaneous feeling that prevented them from believing God capable of having created monsters.°° Nonetheless, their attitude was quickly overtaken by the success of the theory of the preexistence of germs, within the postulates of which teratisms had to be explained.

The most natural procedure consisted in attributing the anomalies, not to the Creator, but to accidents that might have interfered in the course of the development of the germ. As Nicolas Malebranche wrote, if living beings were created at the beginning of the world, it was “nonetheless certain that they achieve their growth only through the general laws of nature, according to which all other bodies are formed, and this has the effect of their growth not always being regular and of monstrous bodies being engendered.” For,

320 THE SCIENTISTS PHILOSOPHY according to a doctrine common to Boyle, Malebranche, and Leibniz, the general character of the natural laws set up by God left room for disorders in detail that did not impugn Providence. The teratism, then, came from a perfect germ altered in the course of development through natural effects — that is, for most of the minds of the age, through chance, for which God was not responsible. It was sufficient for the scientist to determine the nature and action of these natural causes. We have seen that for an entire category of deformities, an interference by

the maternal imagination continued to be assumed until well after 1670.° Malebranche told of a child born beaten to a pulp because his mother had attended the execution of a criminal broken on the wheel.®? Nicolas de Blégny in 1679, Denis van der Sterre in 1687, and Johann Jacob Waldschmidt in 1695 attributed monsters to the maternal imagination, either entirely or partially.° We have also seen, however, that despite the authority of Malebranche, this explanation ended up losing credit,® not only because it was abused, and be-

cause this action by the imagination was difficult to comprehend, but also because it was commonly used to explain teratisms resembling animals, the supposed resemblances to which vanished as soon as anyone proceeded to an unbiased examination. Nonetheless, the idea of an accident undergone by the

germ during gestation quite naturally found adherents. The most common accident was the crushing of twin germs, the result of which was a totally or partially dual teratism. Such were the two baby girls, completely separate ex-

cept for a conjoining from the breast to the navel, reported by the Journal des Savants in 1682.°° The most likely cause of this crushing was an excessive

constriction of the uterus. According to the degree of constriction, the two germs might develop completely while remaining attached to each other, or one of them might develop only partially, which produced beings with two heads on a single trunk, two torsos united in a single pelvis, with two pelvises and four legs united to a single torso, and so on. Sometimes there remained of the second germ only a superfluous member or organ; a leg, heart, or bladder, for example. This explanation, accepted by Claude Brunet in 1686 and confirmed in 1700 by several prodigies that Louis Lémery and Jean Méry had presented to the Académie,°’ had become the quasi-official doctrine of the society. Two other congenitally united sets of twins, presented by Méry in 1702, afforded Fontenelle the opportunity to deliver a formal exposition on them.°® For the adherents of the theory of spermatic animalculi, it was licit to believe, along with Hartsoeker, that such twins came from two animalculi introduced in exceptional circumstances into the same egg.°? In any case, two

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official convictions had to be respected: the first, that no organized matter in the teratism was formed other than from preexistent germs; the second, that chance alone was responsible for the adhesion of the germs and the obliteration of some of their parts. The explanation of teratisms through the accidental crushing of two germs satisfied common sense— not always a virtue in a scientific theory. It was soon to encounter a double difficulty, metaphysical and experimental. The metaphysical difficulty had to do with the very notion of a prodigy. In human eyes, teratisms were automatically a disorder of nature. Just as automatically, the scientist could not make God directly responsible for their existence, pre-

ferring to attribute this disorder to chance. But in so doing, so as not to | accuse God of injustice, he was accusing Him of impotence. Chance would have been overturning the designs of the Creator, an inadmissible notion. Upon closer examination, the true scandal was seen to reside in man and in the temerity that led him to conceive of divine justice in the image of human justice and to impose on God the limits of our own minds. Under the pretext of imagining a God who was perfectly wise and perfectly subject to His own wisdom, man was deifying human reason and its inadequacies, and limiting the infinite freedom of the Creator. Man judged according to human measure a God who went infinitely beyond it. It is easy to see how close this criticism was to the Jansenist attitude to the pretensions of those who sought to regulate the distribution of divine grace according to the blind demands of a perverted human reason. Thus it is not surprising to find the criticism, already fully developed in 1690, in Régis’s Systeme de philosophie. Régis intervened only rather late in the great dispute— called the Dispute between True and False Ideas—that pitted Malebranche against Antoine Arnauld from 1684 to 1687, and the stakes in which were not just man’s hope of attaining the truth but the very idea of God and of His Providence that was to be adopted.”° In his Traité de la nature et de la grace, Malebranche had remarked that “ifa child comes into the world with a deformed and useless head, growing from its chest and making it miserable, it is not because God wished to produce these effects through specific acts of the will. Rather it is because He set up laws for the communication of movements, of which these effects are necessary consequences.” 7! Arnauld replied that God always acted through specific movements of the will, that Creation proved as much, especially that of plants and animals, and that Malebranche himself had been obliged to acknowledge it by admitting the theory of preexistent germs was created specially and individually by

322 THE SCIENTISTS’ PHILOSOPHY God.’ Where Malebranche was looking for the order visible in divine wisdom, Arnauld was attempting to demonstrate the infinite freedom of God and the radical impotence of man.

Régis then jumped in vigorously in favor of Arnauld against Malebranche.’? It was impossible, he maintained, to consider “that God’s understanding and will are two faculties distinct from each other.””4 Hence, I shall not believe . . . that the possibility or impossibility of things may have preceded the act of God's will; on the contrary, I shall remain firmly persuaded that there is nothing possible or impossible except what God has rendered such through His will. In this way, I see clearly that a particular order that I have regarded until now as preceding the act of God’s will, and as serving as a rule for His conduct, is a mere fiction of my mind and an effect of the bad habit I have contracted of judging God as I judge myself. . . . I shall therefore not say, “That God knows things before willing them, that he consults the order before acting, that he follows universal reason.’ ”°

One could not, then, draw a distinction between God’s general and particular wills. God acted “through a simple, eternal, and immutable will that comprises indivisibly and with a single act everything that is and that will be in the future.” ”° Consequently, Nothing keeps us from thinking that the germs of monsters were produced at the beginning like those of well-formed animals . . . , except for its being necessary to say that God cannot be the author of monsters, and that he nonetheless would be if the germs of monsters had existed since the beginning; for it is easy to reply that there

is nothing in the world, save moral evil, of which God is not the author, and that He does not Himself produce very positively, albeit freely. There would be no point, either, in saying that God truly produces monsters, although He would rather there not be any, but he is obliged to create some in order to satisfy the simplicity of the laws of nature: for we shall reply that the laws of nature are in no way different from the will of God, and if one says that God does things that He would rather not do by following the laws of nature, we shall reply again that this is tantamount to averring that the will of God is in contradiction to itself, an inadmissible idea.’”

Not that Régis positively refused to assign an accidental cause to teratisms: he readily accepted that an overly constrictive womb might engender hunchbacked or lame children, that the maternal imagination might give rise to monkey-children, or that congenitally united twins might come from two germs glued to each other.”® But these “accidents” could not be attributed to a chance functioning independently of the divine will, which alone reigned

freely and absolutely in the world, and whose designs man could neither understand nor, above all, judge. In any fashion, directly or not, prodigies

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came from God and from His universal will. Were they then monsters only within our limited understanding? In identifying the laws of nature with God’s will, Régis was faithful to Descartes, for whom God, far from obeying an order that would be in some way superior, was the perfectly free creator of eternal truths. This doctrine, which

_ agreed so well with the Jansenist positions on grace, placed nature more firmly in the hands of God and excluded chance from it. In this way it linked up with a very ancient idea, which Aristotle had already expressed when he stated: “The monster is a being contrary to nature, not contrary to all nature but to nature such as it most often shows itself to us; for, since nature is eternal and necessary, there is no being that is contrary to nature.” ’? Cicero had picked up the same theme,®° and Montaigne, repeating it in turn, had shown how well suited it was for exposing the natural weakness of our reason: What we call monsters are not such for God, who sees in the boundlessness of His. creation the infinity of forms that he has included in it. . . . From His all-wisdom comes nothing except what is good and common and according to rule; but we do not perceive its pertinence and placement. .. . We call “against nature” what arises against custom; nothing whatsoever exists except according to nature.®!

The religious tinge to this passage, in a book that was for a long time the freethinkers’ breviary, should not surprise us. For it was characteristic of skepticism, especially in the seventeenth century, to have a dual face. Fideism and agnosticism were always reconciled in the critique of human reason, the reason in which Malebranche wanted to hear the voice of God. And it was precisely against the freethinkers that Malebranche wrote the Traité de la nature et de la grace, against “the freethinkers [who] persist in saying proudly and outspokenly that the wisdom or the Reason of God is very different from ours... , that what appears just is not so at all, or is not so at all with respect to God, who is the absolute Master of His creatures: that His wisdom, then, and His justice—if one must attribute these qualities to Him —have nothing in common with our feeble thoughts.” ** And it was not a freethinker who

replied to this book that the author had written “in an attempt to justify... the wisdom of God in the construction of His Creation, in an attempt to prove that God is always wise, just, good, and to conceive something by these terms of wisdom, justice, and goodness”:*’ it was Arnauld the Jansenist.*4 Pascal was no doubt closer to Gassendi than to Descartes, and surely than to Malebranche. It is thus not surprising to find Fontenelle restating, in secular guise, an idea likewise held by Cicero, Montaigne, and Régis: “Monsters

324 THE SCIENTISTS PHILOSOPHY are commonly regarded as tricks played by nature, but the philosophers are firmly convinced that nature does not play tricks, that she always and inviolably follows the same rules, and that all her works are, so to speak, equally serious. Some may be extraordinary, but none are irregular.” *° For Fontenelle,

as for Régis, “what pertains to the wisdom of the creator seems still farther beyond our feeble scope than what pertains to his power.” ®° Still, beyond these ambiguities, or, if you wish, these coincidences whose

importance must not be underestimated, the deeper concerns appear clearly different. Malebranche wanted above all to highlight God’s wisdom and the grandeur of the simple and rational order that ruled the world. Chance might appear, so to speak, in the meshing of the net that the intertwining of divine wills, single and general, cast over the universe. In this way, chance escaped these wills and Malebranche’s optimism allowed him to withhold his gaze from the imperfections that teratisms represented as a necessary consequence of the larger perfection resulting from the generality of the laws of nature. Régis, on the other hand, was not at all concerned with justifying God, who infinitely transcended any human justification; he wished above all to show that God was free, and that nothing in nature escaped His power. The order that God imposed on the world was of a wisdom that might indeed appear mad to us, but it was nonetheless wisdom, by sole virtue of being from God. In any case, this order was implacable and without exception. God's will, free and without constraint, was exerted equally everywhere. In sum, Fontenelle scarcely shared Malebranche’s optimism. He no more believed that human thought would be able to understand the order of the world than Régis did. He no more believed in chance than Régis did. But he had little interest in the divine attributes, whether wisdom or freedom. His idea of nature and the limits he saw in mechanism forced him to invoke an abstract God, who had created the universe and established its immutable laws. Moreover, what truly interested him was the functioning of these natural laws, or, at least, the little granted us to know of this functioning. As far as possible, he remained inside nature, behind which he placed a God who, if he had possessed some substance, would perhaps have rather resembled the God of Régis. But Fontenelle’s God had no substance. Malebranche thus attributed teratisms to chance in order to avoid the shame of impiety; Régis attributed them without dismay to the Creator; and Fontenelle, as undismayed as Régis, looked for their cause in the laws of nature, from which all chance was excluded. Like

| Malebranche, but with Régis’s attitude, Fontenelle thus adopted the explanation of teratisms as “accidents.” It would seem, however, that he remained

Problems with Preexistence 325 alone in this stance, at least in the milieux of official science. For most scientists, the choice was between Malebranche and Régis, and the latter’s position was not unavailing. For if chance were excluded from nature, if the most seemingly fortuitous events or the least regular “accidents” in any case executed the divine will, it

was pointless to bring in chance in an attempt to excuse God for the existence of teratisms. The doctrine of monstrous germs existing from the origin of things thus became very tempting, especially as an explanation for certain awkward anomalies. As early as 1689, Méry had reported to the Académie his observations on a soldier who had died at the Invalides at 72 years of age and in whom dissection had revealed a complete reversal of organs: the liver was on the left, the heart on the right, and so on.” What accident could explain this irregularity? It does not appear, however, that Méry drew all the possible conclusions from this prodigy, and the case did not, for the moment, receive much publicity. But the theory of dual teratisms through the crushing of two germs was still problematic when, in 1705, Littre dissected the corpse of twomonth-old baby girl and discovered that her vagina and uterus were divided

in two by a wall. Fontenelle asked himself: How could this double womb have been the effect of a fortuitous accident in development? It is difficult to imagine. Such accidents can destroy, displace, alter certain parts, but not produce new ones. Might it be that two female eggs became attached to each other, and that all the parts of one of them perished, except for its womb, which as a result would have become double in the fetus, because of this blending? This supposition seems a bit forced, and yet there may be nothing more acceptable.**

Indeed, it seemed out of proportion to mobilize a whole germ for a simple wall. But what else could be done at a time when it was impossible to imagine the natural formation of the slightest living tissue? It was not until 1706, however, that the problem was raised in its full dimensions. On September 20 of that year, at the home of a gardener named Michel Alibertin Vitry, congenitally united twin babies joined at the pelvis were born. Immediately “a great number of persons from Paris and its environs hastened out to see them.” ®? The twins died shortly after and were dis__ sected by Duverney, who presented his observations to the Académie during the public inaugural session on November 13. Following a detailed description, Duverney rejected any possible explanation through chance, through “a blind formative virtue,” or through “a fortuitous upsetting of the natural processes.” He backed up his certainty by adducing the highly peculiar internal structure of the teratism: the twins were joined in such a way that they hada

326 THE SCIENTISTS PHILOSOPHY certain freedom of movement but could not possess an anus, whereas each of them had a penis. They were thus able to render only liquid excrements. And the two small intestines, which were separate, channeled into a very short

| common intestine that served as a colon. Now, as was known, the length of the colon functioned to slow up the progress of fecal matter and to thicken it “in order to dispense us of the necessity of having to eliminate it too often.” But in this instance, the matter had to remain liquid, for the unusually short colon emptied into a twin bladder, where the matter mingled with urine before being excreted through the two penises. In this fashion, the absence of an anus, which allowed the twins to move, was compensated for by an utterly original disposition of the organs. Duverney ended his paper in these terms: From the outer envelopes to the depth of the bowels, everything [in this teratism] was of a design guided by an intelligence free in its intention, all-powerful in execution, and unfailingly wise and disciplined in its means.

...In this monster, the intelligence I am speaking of wanted to produce two human bodies joined together, that could stand up, sit down, draw their bodies towards each other or move them away from each other, within limits; and it wanted to guide the solid excrements through a single canal down to a common receptacle where they would mingle with liquids, so that each of these twins could then eliminate them separately through the penis. One cannot help assuming the existence of this will, since its execution is so clearly visible. I leave to the theologians the quest for the reasons behind it; but having assumed the existence of this will, I submit that inspection of this monster displays the wealth of the Creator’s mechanism at least as forcefully as the most orderly of productions, since to all the proofs we have of this _ wealth, our inspection adds this one, all the stronger and more convincing in that, being outside the common rules, it displays more fully both the freedom and the inventiveness of the author of this mechanism, so varied in these kinds of productions.?°

| In this remarkably clear text, the zeitgeist noted earlier is fully apparent. The “Creator’s mechanism” is vaunted for its “wealth” at the expense of its order and is no longer anything but the ingenuity of an artisan in constructing an original device. God is praised for His freedom and inventiveness, and nothing is said of His wisdom, which simple common sense would be tempted to find lacking in the production of a monstrous being. The anatomist was so struck with wonder at the technical perfection of the arrangement of the organs that he envisioned a freak of nature that had failed to survive two days as living, walking, and sitting down. Debasement of the very idea of mechanism; obliviousness to the rational order of the world; admiration before so skillfully mounted a machine: everything was here, everything came together, including the deep and heartfelt conviction that man, face to face

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with the works of God, had simply to admire them and to remain silent, inasmuch as the reason for their existence escaped us. This was, in fact, what the abbé Jean-Paul Bignon brought out when he took the floor after Duverney, first to congratulate him and then to point out that if monsters have been the occasion for not very attentive, or not very learned, people to create difficulties with Providence, they must now serve as an admirable proof in favor of that same Providence: since, varying bodies as it pleases, it knows how to endow them with structures so wondrous, so regular in their apparent irregularity, that they can make us admire the wisdom and omnipotence of the Author of nature every bit as much as the objects that seem to us the most regular.’

Teratogeny was thus forgotten or denied. Observing that none of the teratisms he had dissected was suited for reproduction, Duverney said admir-

ingly: “Is it not so that the Author of nature, having formed outside the usual | order the germs of monsters, does not wish for them to multiply,” ?* without wondering why in that case He had formed them? For he knew very well that the question had no human answer, and if he persisted in wanting to snatch at odds and ends of the divine wisdom as they went by, it was because man could not completely keep himself from wanting to understand. At the same time, Vitry’s congenitally united twins were creating a thorny

problem for the supporters of the crushed-germ theory. Father Pierre Le Brun, from whom the resumé of Bignon’s discourse and Duverney’s confidences are borrowed here, and who had published long letters devoted to the prodigy in the Journal des Savants,? concluded by saying that many people would, no doubt, “be surprised to hear it said that God, from the outset, created in miniature these bodies that we call monstrous.” They would prefer to believe in the fortuitous union of two germs. But “it is difficult to conceive that a structuring as admirable as the one we see in these infants [could stem] either from a simple fortuitous arrangement or simply from the general laws governing the communication of movements.” °* Among those surprised may have been Fontenelle, who says nothing of this matter in the Histoire de |'Académie, although he refers there to congenitally joined twins submitted by the abbé de Louvois in which “the joining of the two eggs or embryos [was] visible.” ?? Henceforth, however, anatomy authorized, if not invited, a different interpretation from Fontenelle’s, and Jean Palfyn, a great reader of the Mémoires de Académie, had no qualms about repeating with respect to teratisms “what of yore was said by the royal prophet: Mirabilis Deus . . . in

omnibus operibus suis [How admirable is God in all his works].” °° | The theory of accidental freaks of nature had not, for all that, entirely lost

328 THE SCIENTISTS’ PHILOSOPHY its credit. In 1716, Méry presented a prodigy that could “only be the effect of a structural defect,”*” which is to say a freak by origin, and Fontenelle had to agree, noting nonetheless that “quite often even monstrous irregularities may be related to certain specific accidents,” and that it “is less frequently the case that one can be certain that a conformation irregular to the point of monstrosity was such from the outset.”’® In any case, this concession bears witness to a certain evolution on his part. Other prodigies, however, could easily be explained by reference to developmental accidents. Such were those that, in the same year, were described by Jean-Baptiste Morin, a physician in Honfleur,”? and by Eustache Marcot of the Société royale in Montpellier. Marcot refused to believe that teratism could already be present in the egg, “which is the work of the Creator, through whom they were all placed in the ovary of the first woman, and from Whose hand comes nothing imperfect or incomplete.” *®° A teratism presented by Littre in'1717 had been produced by a bypassing of the nutritive fluid.'°’ Antonio Vallisneri adopted the theory of crushed germs for congenitally joined twins in 1721 and that of malnourishment for defectives.’°? In 1723, Fontenelle would write: “The production of monsters no longer surprises physicists; we have already stated the general principle of the phenomenon on several occasions.” '”’ In 1724, Louis Lémery vigorously attacked both Duverney and the doctrine of teratogenic germs, which he accused of being a solution of convenience, and above all of being a shocking and evident attack on “the order, simplicity, and uniformity of nature.” !°4 Here again, Fontenelle acquiesced, while noting that Duverney’s opinion was not as gratuitous as Lémery seemed to think, and that the crushed-germ theory was not entirely clear: “It is just as likely —indeed, wouldn’t you say, less likely?— that smashing two good clocks violently together would produce a well-regulated third.” ©? Nonetheless, Lémery presented a teratism very supportive of the crushing theory, and Fontenelle asked no more than to be convinced. In any case, an originally teratoid germ could not have had organs of generation, for “one can conceive that a monster originally formed as such by nature is destined to exist, to live, but one does not at all conceive its being destined to perpetuate its kind.” !°° In the last analysis, the accident and crushing thesis clearly was carrying the day. “It would at least seem,” Fontenelle reiterated in 1727, “that the presumption of truth is quite strong on that side and is constantly increasing in force.” '°” It was in 1733 that the question came alive again, thanks to the intervention of Jacques-Bénigne Winslow, who in this regard donned the mantle of Duverney, who had died in 1730.'°* At the beginning of the year, the surgeon

Problems with Preexistence 329

Sauveur-Frangois Morand had presented to the Académie a teratoid sheep, in which he saw the result of two germs that had come together, but “in a remarkable arrangement and with no confusion.”'°? On May 9, Winslow read a first report,"° which began with an outright rejection of the theory of accidental teratisms. He had reread all the observations put forward on the subject at the Académie, in particular those of Duverney in 1706 and Lémery in 1724. Classifying teratisms as simple and composite, he devoted the first paper to single ones, in the first rank of which he cited the soldier from the ‘Invalides dissected by Méry. “The longer I consider the particularities of all these extraordinary things,” he added, “the less inclined I am to envisage the applicability of the theory of accidents.” '"' According to him, moreover, this was Méry’s own ultimate position. The second report, read the following year,''* examined several instances of composite teratisms, showing how the theory of crushed germs was incapable of explaining them. Winslow's attack was powerful, based upon a perfect knowledge of anatomy and grounded in observations that were unassailable, since they were all taken from the Mémoires de l’Académie. Moreover, Winslow rigorously kept to the scientific as-

pect of the question, without bringing in any reflections of a philosophic or religious order.

Lémery, who was directly challenged, replied only in 1738, and without naming Winslow,’ only Duverney. His scientific arguments remained weak and very general: the germ was “merely like an egg white all of whose soft, delicate, and flexible parts receive and take on with the greatest ease all the extraordinary impressions that come to them.”!!4 The example of vegetable grafts enabled us to understand how two germs might unite.'’? Lémery’s major argument was, however, drawn from the absurdity of the teratism studied by Duverney. The testicles were displaced into the belly, and there were scrota that could serve no purpose. Would God have produced them “if they were to have been utterly useless?” The abnormal placement of the testicles could easily be explained through accidental pressures, “but this disorder becomes morally impossible in the case of originally monstrous eggs, in which nothing should have been done except in accordance with a regular design, since it would have emanated from the Creator.” |’ Lémery went on: Moreover, | have pored in vain over the monster in question, and I must admit that I cannot uncover in it what gave M. du Vernay occasion to exclaim with such admiration at the fair arrangement of this work, in which, as in the attributes of all those of this nature, I see nothing but upheaval, disorder, deformation, confusion, and failed execution.!!7

330 THE SCIENTISTS PHILOSOPHY A single bladder serving four urethras and one intestine, with no other outlet than two penises! “Yet the ridiculous nature of the monstrous structure hardly stops here.” For the parts destined for generation were well formed; consequently, reasoning according to the theory of originally monstrous eggs, it followed that, since the Author of nature had given to M. du Vernay’s monster the parts necessary for the preparation of the seminal fluid, His intention was that the two fetuses of which it was composed should not be sterile.

Now, the two vasa deferentia conducted this fluid into the bladder, thus preventing the monster from reproducing, which is admitted and stated by M. du Vernay as well; that being the case, what becomes of his eulogy on the design and arrangement of his monster’s parts? . . . These parts, instead of helping one another and collaborating in a common function, were at odds with one another. . . . Can contradictions such as these be imputed to the Author of nature? Nonetheless, they are imputed to Him unknowingly, by following the system of originally monstrous eggs, and no more should be needed to justify the total exclusion of this theory.

In sum, teratisms were teratisms—that is, “bizarre and unreasonable alloys,” worthy products of blind accidents, which one could not without offense, however, impute to “the respectable cause to which the theory of originally monstrous eggs directly attributes them.” '® In a manner quite reminiscent of Vallisneri’s Istoria della generazione,'” Lémery’s second paper emphasized the scientist’s right to attribute an effect to causes whose mechanics he did not know: “Can we read clearly enough into the products of nature to be able to see perfectly how each of their causes has managed to produce everything we perceive?” '*° Lémery was quite aware that his anatomical knowledge was inferior to Winslow’s. But the question of teratisms was not in fact a question of anatomy. It was “merely a question of physics, for whose resolution good sense and reason alone are needed.” "7! Did the general characteristics of the teratism, as Lémery recalled forcefully, not irresistibly evoke chance rather than divine wisdom? When one considers, for example, what is virtually always found in monsters .. . — disorder, confusion, deformity, the degeneration and absence of certain functions, certain absurd relationships among parts that were not made to go together, and that are not long in revealing clearly the awkward disadvantages of this bizarre and extravagant union—in brief, an infinite number of oddities all the more pointless in that they are clearly inimical to life, or health, or the functioning of different parts .. . ; is one to say that a design has given rise to such works? Even if it is a design, one may regard it as very poor, since its products are so irrational, so defective. . . .

Problems with Preexistence 331 On the other hand, when, abandoning the idea of assigning design to works that neither deserve nor assume one, we turn to the notion of accidental causes, we immediately find there what had been sought, without its being found elsewhere: all relationship and all proportion possible with the defects and absurdity of monstrous constructions. These causes are blind .. . ; they accomplish nothing . . . ; are these not the only causes that can by their nature be suited to and agree with the nature of monstrous productions? '*?

In Lémery’s eyes, then, moral—or one might say metaphysical — suitability won out over anatomical arguments.

In a third paper, divided into three parts, Lémery returned to the teratoid fetus he had described in 1724, whose accidental character he attempted to prove. Regarding the extraordinary placement of the internal parts, which constituted the strongest argument against fortuitous crushing, he invoked “nature’s resources,” capable of carrying out its designs despite unfavorable circumstances.'*? Unfortunately, he did not pursue this idea, which might have led him far. Finally, a fourth paper in two parts vigorously reafhirmed nature’s order, proven by the fixity of species and ruling out teratisms,'?4 which resulted from accidents similar to ailments of the fetus.'?? Here, once more, Lémery found himself required to substitute an authentically biological idea for the purely mechanistic images of collision and crushing. As for Meéry’s soldier, Lémery freely admitted that no accident could explain the reversal of his organs, and that he had therefore been abnormal from the outset; for this anomaly without ill effects was not a true teratism and could be attributed without offense to God.!?° Winslow finally replied towards the end of 1740, with reference to a teratism practically lacking the upper half of its body. Winslow openly afhrmed

that he was ready in certain cases to accept the theory of accidents. But, he , added, “I will ask for explanations based upon a perfect anatomical knowledge of the structure of the parts.”’”” The theory of accidents must display in each teratism “the traces or vestiges either of a loss or of a joining, or of the two together.” '*® And where these traces were absent, one must be willing to resign oneself to the “wise Pyrrhonism” recommended by Fontenelle in his “Préface 4 histoire de l’Académie des sciences pour 1699,” from which Winslow quoted several lines. It was very difficult to reach certainty in the — science of living beings, and perhaps we must despair of ever reaching it. We must not, however, give up research, and here Winslow spiritedly expressed the tireless humility and hope of the scientist. Let us accept accidents, then, he concluded, where there are no verifiable traces; but for the rest,

332 THE SCIENTISTS PHILOSOPHY I shall stick with what I have quoted above from M. de Fontenelle’s “Préface generale,” joining ranks with those who, not satisfied with such reasoning, simply admit their ignorance in such cases, for lack of evidence, without attempting to invent some theory to resolve their dilemma; and who, far from thinking that their notion of extraordinary originals upsets the uniformity of nature and offends the wisdom or other divine attributes of the Creator, feel that they are thereby rendering full homage to His all-powerful sovereign freedom.'2°

The theory of the preexistence of germs and “extraordinary originals” was thus a metaphysical one dispensing with physical theories, which in the last analysis masked a “wise Pyrrhonism.” As for the religious aspect of the problem, it was broached in just one sentence, but one that nonetheless sufficed to show that Winslow saw things quite differently from Lémery. The latter replied immediately, first of all (and a little disingenuously) to the quotation from Fontenelle; then on scientific grounds; and finally, and most strongly, on the metaphysical level, where he accused Winslow of setting up a contradiction between God’s freedom and His wisdom. Picking up an image he had already used in his “Second mémoire sur les monstres,’ and one typical of the period, he concluded thus: Let us postulate a first-class watchmaker, whose rectitude is equal to his skill: if someone, not knowing by whom some very bad watches had been made, decided to at-

tribute them to our watchmaker, and claimed, in so doing, to celebrate the power of his freedom, which did not require him to make only excellent watches, and that permitted him to make some monstrously bad ones, I ask what one should make of a eulogy of this sort.!°°

Lémery thus always brought the question back onto the same ground. Winslow replied only in 1742, and first of all by analyzing two works on teratisms. One, by Jean-Baptiste Goiffon, published in 1702, was a rather clumsy defense of the theory of accidents; the other, by Albrecht von Haller, published in 1739, backed the theory of original teratogeny with weighty arguments.’*! This time, and perhaps encouraged by Haller’s example, Winslow had no qualms about affirming his religious positions. Haller believed that

it was “not too harsh a thing to attribute the direct creation of monsters to God,” since they displayed “arrangements” that proved “the Wisdom of the Intelligence that formed them, and since it is not a proof of harshness on the part of the Creator that there be some individuals structured in such a way as not to be able to live, or only to be able to live miserably.” Moreover, it was not up to us to know “why God has given these extraordinary structures to some rather than others,” and the Creator, “by forming several archetypes

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or different patterns, impresses upon men a grander notion of His power and His Wisdom, which are bound by no laws of nature, nor subject to any necessity in the formation of creatures.” '°? Although Winslow would have preferred to “avoid stepping outside the frontiers of the academic sciences into difficulties the discussion of which belongs to the higher sciences,” '? he adopted the same attitude. He cited Régis, Duverney, and Bignon; but also, by way of Haller, Saint Augustine. And not only did he defend himself, this time he went on the attack: I feel permitted to ask in turn which of the two sentiments honors the Supreme Being more: to maintain that He has a particular reason grounded in wisdom to do ~ what He does and as He does it, or to say, along with others, that He is countermanded in the workings of his general laws by secondary or occasional causes that prevent the execution of his initial designs? This is, however, the awkward situation into which those who find nothing worthy of God except what adheres to uniform laws must find themselves. Moreover, does their system not seem to imply some sort of impotence in the All-Powerful? !34

God was not a watchmaker, and the world was not a clock whose mecha-

nism man could judge. “Man cannot discern how the different divine attributes, infinitely beyond the reach of our intelligence, function in these productions, taken either as a whole or considered individually.” !*°

Lémery, who was ill, did not reply, and the dispute seemed to be ended. Winslow returned one last time to the subject, however. He justified himself painstakingly with regard to Lémery’s attacks; he recalled that he had always accepted the theory of accidental teratisms in certain instances.'3° Above all, however, he came back to the prudence one must maintain in scientific matters and did not hesitate this time to extend his skepticism to the preexistence of germs itself: M. de Réaumur’s observations on various reproductions that occur in crayfish . . . have made me very guarded on the mystery of the propagation of species. . . . Finally, the variously repeated verifications that M. de Réaumur has made of the astonishing multiplication of aquatic polyps through a kind of cloning, entirely confirm for me the necessity for my being guarded. . . . These reproductions from some part of an animal, and these complete productions of an entire animal from every tiny piece of an animal cut to pieces, provide strong objections against all the systems advanced so far on fertilization and on the lineaments of fetuses in unfertilized eggs.!97

Lémery had attempted to break the iron collar of mechanism by invoking the “resources of nature.” He died on June 9, 1743, never to learn that his adversary —also shaken by the problem of teratisms, as well as by that of re-

334 THE SCIENTISTS PHILOSOPHY generations — was in turn finally calling into question the very doctrine that raised these problems and made them insoluble. In this debate, Winslow had considerably dominated Lémery, not only by his knowledge of anatomy, but also by the clarity and firmness of his thought and expression and the dignity of his moderation. From the theological point of view, his position was immune to attack, as he proved one last time by quoting a text from Saint Augustine as restated in a decision of the Council of Trent.'%* Nonetheless, despite anatomy and despite theology, he had perhaps not remained insensitive to the needs of humanity that had been proffered against him. “The system of originally monstrous eggs had always revolted me,” Lémery exclaimed in one his papers.'*? Winslow had perhaps understood that revulsion and had looked deeper for the causes of the debate. This debate, then, was finished; but its echoes continued. It was only in 1744 that the Journal des Savants reviewed the academic debates of 1740, siding with Lémery, whose system “seems more in conformity with the laws of the Creator; is that not sufficient to accept it?” !4° The most important commentary, however, .was that by Dortous de Mairan, who had become secretary of the Académie in 1739, upon Fontenelle’s departure.'*! In the Histoire de l'Académie’s report on the 1743 transactions, Mairan clearly sided with Winslow and implied that the majority of academicians did as well.!4? While pointing out that there had been no discussion of teratisms before preexistent germs had been thought of, he did not for a moment raise doubts about preexistence. He even opined that the regeneration of polyps proved nothing, because it could be explained in a perfectly natural fashion by way of germs.'* As for the basic problem, he drew special attention to a difficulty that had not been sufficiently noticed: in order to explain the accidental union of germs, people emphasized, he said, “the softness and fluidity of the substances composing the fetus.” Nonetheless, the supplementary parts were not placed just anywhere: a second head would appear next to the first, a sixth finger would be attached to the hand, and this assumed an order that was impossible to understand through a purely fortuitous gathering of soft and fluid parts. For a calculation of probabilities showed how little chance there was that a finger would join itself to a hand rather than any other spot. It became totally improbable that the same throw of chance would occur four times in the same individual, as with a child with six digits on each foot and each hand that had just been presented before the Académie. There still remained, then, the metaphysical objection to originally teratoid germs. This objection was valueless, however: no one wanted to believe that God created teratisms directly,

, Problems with Preexistence 335 as if we were inside the counsel of the author of nature, and as if the entire world did not present to our sight a thousand other, more important irregularities, as judged according to views as limited as ours. We seek the Creator's will within our lights, whereas it manifests itself in execution, and instead of attributing the formation of these wondrous creatures—despite the odious name of monsters that we have set upon them—to an infinite Wisdom that hides its motives from us, we prefer to see them as the product of chance or of a blind formative virtue. And if anyone should insist that the Creator produced monsters merely to observe the simplicity of the

laws of nature, we shall reply that the laws of nature are in no way different from the | Creator’s acts of will.144

Thus, Dortous de Mairan in 1743 was repeating almost verbatim Régis’s formulation of 1690. If teratisms did not survive, he continued, it was because we did not take care of them. But after all, of what concern is it to nature, so rich and fertile in wondrously organized individuals, that the life of some of them should be so short? She produces at every moment thousands of them destined to live only a day, and every day other thousands that die under our feet, or that were born only to serve as food for their . fellows.145

No doubt Mairan was aware that he was showing himself to be “a bit more decisive than M. Winslow.” !4° But he felt strengthened by the backing of the majority in the Académie, as well as by the perfect consistency of his own thought. In fifty years, the problem had not progressed an inch. How, in any case, could things have gone otherwise? Resting on the same scientific foundations, there were two mind-sets in confrontation without the possibility of convincing or even understanding each other. From Arnauld and Régis to Dortous

de Mairan, passing through Duverney and Winslow, it was the same religious perspective on nature, the same deep conviction that man was totally incapable of access to the wisdom of the Creator, whose infinite freedom bore no relationship to our “foolish reason.” The beings on which we had “set the odious name of monsters” were in reality “wondrous beings.” They were wondrous because they were the work of a God who had no accounts to render us and who merely allowed us to glimpse His omnipotence “in the execution” of these incomprehensible wonders. We should not be surprised, moreover, that Duverney and Winslow, the greatest anatomists of their time, should have adopted precisely this attitude. Their will to be merely observers made them mistrustful of the theory of accidents as “theory.” The actual facts did not agree very well with Lémery’s theory. And above all, the more teratisms these anatomists examined, the better they knew them, and the more

336 THE SCIENTISTS PHILOSOPHY absorbed they were in the painstaking contemplation of their organization, the more they admired their artful complexity and the less tempted they were to seek in an impotent nature the cause of these monstrosities, so regular and so ingenious in their very disorder and absurdity. The prudence of the scientist and the humility of the Christian blended effortlessly in them. The common sense invoked by Lémery and the affirmation of a universal order remained general considerations, vague and lacking in weight for scientists who at each moment were discovering new traces of the hidden God. The anatomists thus joined hands in common religious wonder with Leeuwenhoek and the microscopists, with Réaumur and the insect watchers.!4” Still, this long dispute had been made possible only by virtue of the theory of preexistent germs or, more precisely, by the mechanistic vision of life, of which preexistence was virtually a necessary consequence, even while underscoring its failure. Winslow himself, although he sensed the damaging role and the inadequacy of this doctrine, could put nothing in its place. No doubt Winslow was also influenced by Augustinian thought, the importance of which has been noted. In 1740, however, this current of thought could do no more than reinforce among religious minds the tendencies that mechanism had imposed on everyone. Preexistence rested on the conviction that nature, as a mere mechanism set up by God, was incapable of forming a living being. It was also incapable, then, of forming the slightest shred of living matter, and Fontenelle had to assume a germ, complete and yet vanished, in order to explain the presence of a single superfluous membrane. Outside of the structures made by God himself, there was room only for chance, and Dortous de Mairan calculated the probability of four excessive, but properly situated, fingers. Lémery himself could not escape the thralldom of this perspective, and for everyone the crushing of two germs evoked Fontenelle’s two clocks smashing together. The theory of accidents was powerless to explain undeniable facts suitably; yet to make God directly responsible for teratisms was repugnant to reason. To escape from this dilemma, it was necessary to give up belief in the preexistence of germs—that is, in the passivity of nature.

IV The Rebirth of Vital Forces

The new science that imposed its authority starting in 1670 recognized only God and mechanism. Along with “forms” and “faculties,” it excluded

Problems with Preexistence 337

“directive intelligences,” “archei,” and other spiritual powers. Perrault’s animism had no reverberations, and if people continued to concede that animals had souls— despite Descartes —they saw in these a kind of imperfect reason rather than a principle of life.4* The matter seemed definitively settled, at least among the well-informed, when Jean Le Clerc went to the trouble in 1703 of digging up an already old work that had remained unknown on the Continent, Ralph Cudworth’s The Intellectual System of the Universe, originally published in London in 1678. Cudworth, who died in 1678, had been

a professor of Hebrew at Cambridge and a friend of Henry More’s. Passionately devoted to Platonism like More, and a great enemy of ancient and modern atheism, most particularly that of Hobbes, he had it in for Cartesian mechanism, which according to him led as inevitably to atheism as that of Democritus, even though such had not been Descartes’s intention. Le Clerc was to give new life to the tradition of Helmont, and even of the Neoplatonists of the Renaissance, in an updated form. Le Clerc may have had personal reasons for reviving this forgotten work.14? But above all he was able to regard it as a weapon in defense of Christianity against the progress of atheistic mechanism. For four years—from 1703 to 1706 — he published very long digests of the book regularly in his Bibliotheque choisie in order “in some way to make it known to the public” that was unable to read it in English.’?° This abridgment, which Le Clerc regarded as “one of

the finest adornments” of his journal,'*! was to have considerable repercussions. Indeed, Cudworth began with a violent attack upon Democritus and atomistic-mechanistic atheism, which still counted many adherents in 1703.

On the other hand, he was far more discriminating with respect to Strato of Lampsacus, the Stoics, and hylozoic atheism: he condemned atheism, but not hylozoism in itself, and in a long digression, he set forth his own view of nature.!°? If the universe were no more than a mechanism, he said, there were only two solutions: Either, in the formation and organization of animals’ bodies as well as in other phenomena, everything is due to chance and becomes what it is without being either led nor directed by a spirit or an intelligence; or else God Himself makes everything directly and, so to speak, forms with his own hands the body of every gnat, fly, insect, and moth, as well as all other animals at the moment of their generation; all being animals whose members bear witness to so much ingenuity that Galen asserted that he could never sufficiently admire the art contained in the leg of a fly (and yet he would have admired still more the wisdom of nature had he known the use of the microscope).!>4

338 THE SCIENTISTS PHILOSOPHY The first hypothesis is ridiculous and impious, as Henry More had properly demonstrated in his Enchiridion metaphysicum [1671].°4 But the second was no more reasonable. First of all, it supposed that God was constantly busy creating beings, which was incompatible with His dignity and would give the advantage to the atheists.’ Moreover, Cudworth continues, it seems not very reasonable that nature, insofar as it is a thing distinct from the Divinity, should be completely supplanted in its activity, or rendered useless, with God making all things directly and miraculously; for the consequence of this would be that all things are made through force and violence, or merely in an artificial manner, and none through an internal principle proper to it.!°°

Remarkably, Cudworth’s desire to preserve the autonomy of nature, making of it “a thing distinct from the Divinity,” was a factor in alienating him from mechanism. Nature’s “independence” was attested by the facts: the generation of things was effected “through a slow and gradual process,” which would be “an empty and futile pomp or a frivolous ceremony” if God, who could do everything in an instant, were Himself acting. Then, too, the “mistakes,” the “failures” of generation stemming from defects in matter, proved

that the active agent was neither “irresistible,” nor “infallible,” nor “allpowerful.” '°” Le Clerc gave particular emphasis to this argument, refusing to attribute the existence of teratisms to God.!8

To escape this dilemma created by mechanism, one had then to accept “that there is a plastic nature under [God’s] orders, which, as a lower-level and subordinate instrument, performs slavishly that part of His provident action which consists in moving matter in a regular and orderly way.” '°? This “plastic nature” had been accepted by many philosophers— Aristotle,

Plato, Empedocles, Heraclitus, Hippocrates, the Stoics, the Neoplatonists, the modern Peripatetics, and even the Paracelsists, who baptized it the Ar-

| cheus. There would, of course, be attempts to combat it by labeling it an “occult quality,” but recourse to an occult quality was merely an admission of ignorance, whereas the “plastic nature” was the only intelligible cause of the order of the world, which the “fortuitous Mechanists,” great slayers of final causes, were having a very hard time explaining.'®° What remained was to define the plastic nature. Cudworth recognized the difficulty in conceiving of it and did not give an exact definition. From his lengthy explanations,'®' we may conclude that it is a being that has received from God a creative power far above that of human art, without possessing any knowledge or awareness of what it is doing. Cudworth’s thought is imbued with vitalism: “Nature is

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art, so to speak, incorporated and incarnate in matter, [an art] which does not act upon it from outside and mechanically, but from inside, vitally and magically”;'©? “nature is something that does not know, but merely acts.” '® No doubt modern philosophy refused to recognize the existence of a spiri-

tual being without thought or awareness. But experience proved that such beings could exist: a man who was sleeping or in a swoon did not think; the plant called sensitive reacted to contact without thinking; automatic acts such as the beating of the heart were carried out without thought. All these functioned due to the plastic nature, which was not however a material being, for “even though it is the lowest of all kinds of life, nonetheless, since it is living, it must absolutely be incorporeal.” '°* Indeed, only a spiritual being could assure the unity of the living being and guide its formation. Aristotle, and above all his commentators, had erred badly in not being specific on this point. Finally, Cudworth explained how the entire universe, as well as each of its parts— Earth, planets, and the totality of the solar system—also had to possess their plastic natures.

THIS WAS the broad outline of the system that Jean Le Clerc presented to the public and to which he officially gave his approval. It was not a matter of denying, in strict terms, the mechanical character of nature’s operations but, in Le Clerc’s view, as in Cudworth’s, of defending the power of God over His Creation and subordinating mechanics to a spiritual principle, which would be a docile executor of the divine will. Nonetheless, juxtaposed to a science scarcely tempted by atheism, Cudworth's system was tantamount to replacing the direct intervention of the divinity with the action of plastic natures, an action subordinated to God but nonetheless natural. Cudworth mutilated mechanism in order to grant nature its own existence, and this was to be the point underlined by Pierre Bayle’s critique. Meanwhile, and at first blush, the plastic natures were simply a new version of the “hylarchic principles” whose existence Henry More had maintained in his Enchiridion metaphysicum; and these had never found much support. From very close up, moreover, these “natures” or “principles” resembled Helmont’s archei. But Le Clerc was not Martin Heer, and if he was prepared to affirm like him that “the anatomist’s knife cannot get to the vital actions,’ '®? nothing in either his vocabulary or the sum of his thought evoked an outdated chemistry. The problems he broached were, on the contrary, most timely, and he was able to give direct proof of this in the same volume of his periodical, in his review of Nehemiah

340 THE SCIENTISTS’ PHILOSOPHY Grew’s Cosmologia sacra, which had appeared in 1701.'°° The great English botanist and microscopist could scarcely be considered a backward spirit. Nonetheless, Grew had devoted book 2 of his work to the demonstration of the existence of a “vital world” separate from the material world. For, he said, life did not consist in the shape or the movement of matter nor even in its organization, even though the latter had to be in conformity with the kind of life with which the being was endowed. Rather, life was the work of a vital principle, of which there were several types, which Grew reduced explicitly to the old notions of vegetative, sensitive, and intellective souls.6” Le Clerc did not fail to point out how closely these ideas agreed with those of Cudworth.

Despite Grew's authority, these opinions ran the risk of appearing too contrary to ruling doctrines to gain serious attention. But Cudworth’s plastic natures had the good fortune, so to speak, of being noticed by Bayle, who was always attentive to what Le Clerc was publishing.'®* In the Continuation des pensées diverses sur la cométe, published in August 1704, Bayle undertook to discuss them, just as he had already discussed the “hylarchic principle” of Henry More.'® Essentially, he accused Cudworth and Grew of abetting the very atheism that they wanted to combat by accepting the notion that plastic natures could form animals without knowing what they were doing. A disciple of Strato of Lampsacus [3d century B.c.] would deduce from this

that the world, despite its order and regularity, might be the effect of a blind cause.'”°

Le Clerc quickly replied, complaining that anyone should think of discrediting the religious sentiments of Cudworth, Grew, and himself. Moreover, because the plastic natures or vital principles were strictly immaterial, and thereby different from Aristotle's “forms,” and because they received that power from God, they could not abet atheism.’”’ Bayle replied in turn that he harbored no doubts about the religious sentiments of his opponents, and that before Descartes, everyone had accepted the notion that God, as an intelligent cause, had his wishes carried out by the active and non-intelligent faculties of nature. But the nub of the problem was the following: either the plastic natures were purely passive instruments in the hands of God, in which

case the atheists derived no advantage from them, but we were back with the passivity of nature and with a God who was the direct cause of all things (which we wanted to avoid); or on the other hand, the plastic natures had-an activity of their own, and then Strato’s atheist could appropriate them. Besides, how could spiritual beings act on matter?’”?

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Bayle’s intention was above all, however, to “show that a system that attributes a true activity to inanimate creatures can be turned against itself to unfortunate effect, which is not to be feared in Cartesianism.”’”* This meant that one had to exclude nature under penalty of being an atheist,!”4 and Bayle understandably ended his discourse by stating his preference for the system of occasional causes. However, one might also note that Descartes did not exclude nature in this way, and that Bayle was in fact referring, under the name of Cartesianism, to a philosophy that was rather that of Malebranche than of Descartes. What seems to have been inconceivable in his eyes was the idea of a vital activity different from a conscious activity. True enough, by affirming the spiritual character of the plastic natures, Cudworth also showed himself incapable of abandoning the concept of a purely passive matter. But he did include something other than matter in nature. The debate between Bayle and Le Clerc continued until 1706, soon complicated by a renewal of their past discussions on Manicheanism and God's goodness.'”° The tone quickly become personal and impassioned, especially with Le Clerc, who finally accused Bayle of simply wanting “to excuse the atheists” and to place atheism and religion on the same footing.'”° The importance of the dispute for us lies, however, in its having forced Le Clerc to clarify his ideas and to revive forcefully notions that had been thought gone forever. “In plants and in animals,” he wrote, “there is something called Lie, or an internal principle of vegetation, movement, and even of feeling, labeled the vegetative and sensitive Soul by the Scholastics.” '”” Modern philosophers were “mistaken in believing that the scope of their own clear knowledge is the measure, so to speak, of what is in nature, and that there is nothing beyond that.” '78 The plastic natures resembled the instinct of animals. Birds, which build nests, hatch their eggs, and feed their young, act in this way through instinct, in Scholastic parlance—that is, through a principle that, though blind, makes them act out of necessity, according to a certain order that it does not itself know.

If one grants znstinct, 1 do not see why one would deny the plastic natures. But M. Bayle will no doubt reject instinct as I have just defined it. Therefore, according to him, it is through knowledge. The problem is that this opinion is completely indefensible, because of the absurdities into which it draws us.!7?

For birds would have to possess superhuman knowledge, as demonstrated by their behavior, which Le Clerc described at length. Bayle did not fail to reply that to define instinct in this way “was to bring back the occult faculties of the Scholastics,” and that in so doing, Le Clerc had “offered himself up to

342 THE SCIENTISTS PHILOSOPHY the mockery of all modern philosophers.” 18° Le Clerc, however, responded to the challenge, asserting that the occult faculties of the Scholastics are not to be rejected indiscriminately. If one thought to account clearly for nature’s effects by saying that they occur by virtue of the occult qualities, as the Scholastics are accused of having done, one would no doubt be wrong. But when one said that the properties, or the internal qualities of bodies, from which are born most of their effects, are occult or unknown to us, and consequently that we cannot give a sure reason for these effects, one would be saying what is true, and would speak better than those who offer empty conjectures as truth.1®!

The importance of these assertions is apparent. Not only did Le Clerc revive the vegetative soul, even specifying that Descartes had never succeeded in proving that it did not exist,'*” not only did he revive instinct as a principle entirely different from reason, but one even senses him sliding, although he denied it, towards a vitalist conception of living matter. He vigorously affirmed the spiritual character of the plastic natures and refused to identify them with the Aristotelian “forms”; but unintentionally (as Bayle had clearly seen) he was opening the way for those who would consider the vital principle as an essential quality of living bodies. Mechanism wished to ignore the “internal quality of bodies” completely: it recognized only shape and mo-

tion. Le Clerc restored them, had no qualms about bringing back notions employed “in the School,” defended the Scholastics against Descartes—and all this without seeing the possible consequences. Nonetheless, Bayle was wrong in believing that Le Clerc was reviving only an outdated past. Quite the contrary, he was expressing utterly modern tendencies, first and foremost in combating Cartesian mechanism, the instigator of atheism. Leibniz, joining the fray, had been able to say that Cudworth’s “excellent work” had pleased him “very much for the most part,” and particularly so when it denounced the inadequacy of mechanism and the feebleness of Descartes’s argument.'** Above all, Le Clerc, very much abreast of the evolution of English thought, reflected its tendencies faithfully: close attention to the facts of nature; mistrust of “clear ideas” that satisfied the mind but did not correspond to any reality; a profound conviction that man could not truly comprehend things, and that one was permitted to assume beings or forces of which we had no distinct idea if their existence was required in order to explain phenomena; indifference, finally, with respect to a supposedly immutable order that would prohibit God from intervening in the universe in the present, either directly or by the mediation of forces carrying out His free decisions. On all these points, Le Clerc was opposed to the French mecha-

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nists, who had wanted to restrict the scope of mechanism through belief in the preexistence of germs, but who refused to abandon their clear ideas and to see in nature something other than matter and motion. In fact, Le Clerc went beyond them still more than he opposed them. The debate on plastic natures preceded only slightly the debates to be elicited by Newtonian attraction.'8* As non-mechanistic principles acting within nature, Cudworth’s plastic natures foreshadowed attraction. They also foreshadowed the approaching decline of a mechanism whose ruin its defenders had themselves begun with the theory of preexistent germs.

Le Clerc failed to convert the scientific world to plastic natures notwithstanding his perseverance,'** but everyone knew of their existence, and Fontenelle, Bourguet, and Voltaire gave witness of at least having heard of them.'8¢ The idea of a “vital principle” was henceforth launched in circles from which the thought of Francis Glisson and Henry More had practically been excluded. The fact of adding another being to the only two substances — thought and matter— recognized by the Cartesians was not itself new. Many scientists of the old school still did as much. Despite Descartes, the action of the soul on matter had not been universally repudiated, and as we have seen, Bayle, who criticized the plastic natures as unconscious, seems to have accepted the existence of an intelligence regulating the movement of atoms.'®’ What was new was that ideas of this sort should be defended by a man who was thoroughly up on modern science, and should be presented as a necessary corollary of the most recent scientific investigations. The same was true, indeed, in the case of Georg Ernst Stahl, whose most revolutionary writings appeared between 1706 and 1708.'*8 In many respects, Stahl stepped forward more as an heir to the old medical tradition than as a disciple of contemporary investigators. But the vigor of his condemnation of mechanistic medicine in the name of its results, and his arrogance in presenting himself as the savior of a decadent science, clearly signified his intention to lay the groundwork for the future rather than to perpetuate the past. His Paroenesis ad aliena a medica doctrina Arcendum (1706) recalls the tone of Descartes’s Discours de la méthode: “What shocked me above all was that in this physical theory of the human body, life, even from the outset, was glossed over in silence, and that I saw nowhere a logical definition of it.” !®? It took courage, moreover, to write in 1706: “I formally deny that anatomy is an integral part of the medical art,”'?° or yet again, “as far as chemistry is concerned, it is still a true statement that, up until now, this science must be regarded as completely foreign and irrelevant to true medical theory.” ’”!

344 THE SCIENTISTS PHILOSOPHY Stahl did not deny, in any case, that the organic had to display “a mechanical structure.” '°? But raw mechanics offered nothing, according to him, but “occasional causes,” which is to say—and here Malebranche was irrelevant — causes “that produce nothing under the influence of their act but fortuitous instances. '”? Pure mechanism was nothing more than chance. The organic, on the other hand, recognized only the “efficient cause,” the one that “tends

and aims at a certain result, seeming to act only towards that end, and so perfectly in accord with it that, where the end does not exist, there appears neither agent nor act and that, on the contrary, everywhere this agent appears, there also is found its inseparable aim; and reciprocally, where one sees the end, one also sees the agent.” !?4 The organic was the mechanical oriented towards an end. Stahl therefore deemed legitimate the quest for final causes on condition of limiting it to the organism itself without attempting to reach the universal ends of things.’”? In this way, Stahl’s teleology tended to distance itself from that of his contemporaries and to join hands with that of Aristotle. And this is confirmed by Stahl’s concept of the living being: the mechanism of life could not content itself with being oriented, or perhaps pre-oriented, at the moment of its construction, as the partisans of preexistence think. For if an alloy or an ordinary chemical compound was homogeneous and stable, a living body was by nature heterogeneous and doomed to dissolution if aban-

, doned to itself.1°° A principle of life had therefore constantly to be present to orient the vital mechanism and preserve it from this dissolution. Starting with the Paroenesis of 1706, Stahl affirmed that it was the human soul “that accomplishes its work in and on the body, as powerfully and for as long a time as it can,” thanks to “the circulatory movement of the humors.” '?” This was not a new solution, and objections were at hand. Stahl strove to refute them one by one. The soul, it was said, was a spiritual being that could not act upon matter. Yet experience proved the contrary. The passions of the soul could modify physiological movements, accelerating, for example, the rhythm of the heartbeat.'?* Maternal imagination acted upon the fetus, and anger made the blood run faster.’?? It was therefore certain that the soul was provoking and directing their vital movements,”°° and analysis of its faculties and its modes of action proved that it was “set up to be involved in material things” and, “as an active being,” to act upon passive matter.”°’ Moreover, upon close inspection one saw that movement itself was as immaterial as the soul.” It might still be objected, however, that the soul was totally ignorant of the vital organization it was supposed to direct and was never aware of regulating its movements. Stahl responded by distinguishing —as the Italian

Problems with Preexistence 345 humanist philosopher and physician Giulio Cesare Scaliger had already done to defend a similar theory — between direct knowledge (/ogos), which was a direct intuition, and reflective knowledge (/ogismos), which was conscious. The soul had direct knowledge of the organs and their functions, and this knowledge was conscious in the newborn; but in the adult it became unconscious because of habit and because of the invasion of awareness by sensations from outside, as well as by the activity of reflective thought.” Stahl’s Theoria medica vera, published in 1708, added nothing essential

to the four dissertations that had preceded it, but it made them more complete on certain points and specifically added a theory of generation.?* As might have been expected, it was the soul of the child that formed its own body.”°° We might recall, however, that this old theory raised a classic objection: how could the soul reside and act in a formless embryo? Stahl borrowed his response from contemporary science: he adopted ovism, citing Malpighi's

observation on the first lineaments of the chick found in the unincubated egg. Through a by now classic mistake, he came to believe that these lineaments had been seen in an unfertilized egg and asserted with self-assurance: “This primitive lineament, composed of the brain, the medulla oblongata, the spinal cord, and finally the nerves, is in fact nothing other than the first and principal organ or instrument of the soul itself.”*°° The mother thus provided a matter just sufficiently preformed for the soul of the embryo to be able to act upon and form the body, without its being known, however, whence the soul came.”®’ It might possibly come from the father, whose role would otherwise be difficult to determine.”°* Stahl was vague about this, and thus avoided the serious and well-known difficulties that the slightest specificity could not have failed to raise. This theory of generation, in which the author was scarcely interested, and that possessed little originality, would in any case not have sufficed on its own to ensure the success of a work written in an obscure, overblown Latin and stamped with aggressive vanity. Stahl’s ideas were important largely for medicine, and their influence would be felt

in France only later, through the mediation of the doctors of the School of Montpellier. The mere existence of such ideas had, however, to attract attention in their time. Like Cudworth and Le Clerc, Stahl! surely owed much to the past, and especially, it would seem, to Helmont.2” By identifying mechanism with chance and declaring it incapable of forming a living being, Stahl

was merely repeating ideas that were to be found everywhere, but his critique went beyond that of his contemporaries. His dynamic conception of life, which he conceived of as a constantly interrupted and constantly re-

346 THE SCIENTISTS PHILOSOPHY established equilibrium, his recourse to a spiritual principle, which required him to reject the ordinary conception of the relationships between soul and matter, not only foreshadowed and paved the way for a complete revision of the basic principles of biological thought, but also show that as early as the beginning of the eighteenth century, this revision seemed necessary to a few independent minds. Like Le Clerc, however, Stahl was opening up a path that risked leading much farther than he might have wished. The novelty, as well as the dangers, of his reform appear clearly in the violent criticisms Leibniz directed at it. By accepting a non-mechanical element in the organism, Stahl was said to be opposing the “admirable decisions of the moderns, who have rightfully established that nothing occurs in the body that is not produced by mechanical —that is, intelligible— reasons.” 7!° Rejecting mechanism thus amounted to rendering all science impossible. Moreover, according to Leibniz, Stahl could not avoid falling into materialism, whatever he might say about it. “The soul gives the body no movement, no degree or direction of movement, that is not the automatic consequence of prior states or movements of matter. To assert the contrary is either to change the soul into body or to return to unexplainable principles.” ?"' One particular instance brought out, for Leibniz, the latent materialism in the doctrine: a heart removed from the chest palpitated for several instants. If this movement was due to the soul, as Stahl claimed, this meant that “the soul of the animal is divided into parts and remains partially in the excised heart.” 7’? Moreover, everything was thus immediately clarified: the soul was matter, and we were back with mechanism.?’? But this was clearly not what Stahl intended. Outside of pure mechanism and the preexistence of germs, then, there was no salvation: Cudworth’s plastic natures abetted atheism because they acted unconsciously; Stahl’s animism led to materialism because one had to accept that the soul acted upon the body. Cudworth, Le Clerc, and Stahl were wellintentioned, but Bayle and Leibniz were more perceptive, as a look at the quite unorthodox ideas of Nicolas Hartsoeker quickly showed. It may be recalled that in 1694 the latter had proclaimed his adherence to the theory of the preexistence of germs, which he even claimed to have invented. Later on, he had devoted himself above all to physics, constructing a system of his own, which he set up against those of Descartes and Newton, simultaneously rejecting the plenum envisaged by the former and the vacuum proposed by the latter. This had led him to assume a “primal element” that was rather difficult to conceive of, since it was “completely pure fire” —that is to say, “a being with extension that is not a body, that nonetheless is a real being, that can

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act, impel the atoms or little bodies floating in it, and keep these atoms from colliding with one another.” 214 More serious still, Hartsoeker openly rejected the Cartesian theory of the animal-machine, judging it necessary to grant animals “a soul that reflects on its actions, that remembers its past, that foresees the future, that compares its ideas and draws conclusions from them.” ?" Once he got going, he even ceased to believe in the mechanics of the vital

movements, which he explained by reference to “a soul, whatever it may be— , possibly a portion of my primal element—that, residing in the cerebellum until such time as it withdraws from there to become absorbed, so to speak, by the great soul of the universe, impels the vital spirits” and “performs all the functions we call vital, without our participation, which is to say, without the participation of the soul” properly speaking.*’° All this had been accompanied by rather unorthodox considerations on thought and extension: Descartes, Hartsoeker claimed, had considered them substances, whereas they were merely qualities. Therefore, “thought and extension may have nothing in common with each other, and yet belong to the same substance.” This was how bodies could possess extension and motion, “even though one need not conceive of motion to conceive of extension and even though these two things have nothing in common with each other.” 7” Hartsoeker may well have been reading Spinoza.?'* From this time on, moreover, he found himself accused of atheism by the Jesuit memoirists of Trévoux.’!? He defended himself vehemently, but his very defense was taken as a proof that he was a deist: there was a way of attacking “superstition” that was immediately recognizable.?*° With principles such as these, one should go far—as the future was to bear out. —-

Nonetheless, it seems that Hartsoeker still accepted the preexistence of germs.°*? One day, however, his patron the Palatine Elector informed him of Réaumur’s experiments on the regeneration of crayfish legs. It was a sudden illumination. He had accepted until then that preexistent spermatozoa were imbibed into the body with air or food. Now he rejected “so absurd and bizarre a thought.” *”? If he had accepted it in his youth, it was because he was “still filled with Cartesian ideas, and with the opinion that everything happened pretty much through mechanical laws alone, without the aid of a soul or an intelligence.” *?> The crayfish experiment opened his eyes, and he took the first opportunity to publish his new “conjecture.” This opportunity was Offered him by Jean Le Clerc’s review of George Cheyne’s Philosophical Principles of Natural Religion.2** Cheyne accepted the preexistence of germs and encasement and found in them an argument against the eternity of the world: the first created beings would have had to be of boundless size in order

348 THE SCIENTISTS’ PHILOSOPHY to contain their entire posterity in their wombs. The argument was not worth much, for where was one to find the first created beings if the world was eternal? But Hartsoeker did not fasten on this detail. He wrote to Le Clerc, who had in any case taken advantage of the occasion to reafhirm his fidelity to Cudworth’s plastic natures, and who published a virtually complete version of the letter, in which Hartsoeker took issue especially with Cheyne’s Newtonianism, but also in passing demolished preexistence and encasement, “suppositions that the experiment performed on crayfish clearly contradict.” 7”? Por “the mechanical formation of a single claw, or leg, is no less inconceivable, nor less impossible,” than that of a complete animal, “and it is no less

absurd to think that God would make a new creation out of it. Thus we must by absolute necessity have recourse, for this, to an intelligence, whatever it may be, that dwells in this animal and that repairs the loss, as soon as it happens.” 77° At the same time, one might also think “that the same intelligence made and constructed this animal in the body of the male that begot it; that it constructed the animal invisibly, with art and science, according to the power that it has received for this purpose from a higher intelligence, and that it cares for it, as much as possible, throughout the course of its life.” There were, then, intelligences “that have under their direction a portion of matter, which they deal with freely, since they fail rather often in their productions.” Each man possessed one, “for who would wish to maintain that God himself moves our members... , makes our blood circulate continually ..., or that all this is carried out through the laws of motion?” *?7 Le Clerc made no answer, at least regarding the crayfish, and Hartsoeker returned to the issue five years later,?** this time attacking preexistence on grounds of the necessarily inconceivably small size of the encased germs.’ “But if this theory is false, would one not be forced to maintain that God produces everything continually and endlessly, as with his own hands, or that the world is merely a great machine that moves only through an initial impulsion that God impressed on it at the outset, and that nothing thus occurs in it except through pure mechanics?” ?*° This had been the alternative posed by

Cudworth, in almost the same terms. Here, the “subalternate intelligences” supplied the required solution, and Hartsoéker developed their advantages with arguments recalling those of Stahl: “It is not the salves and plasters that cure me when | am cut or injured, but the intelligence dwelling in my body.” The plasters took care of air and fluids, “but it is the intelligence inhabiting my body that alone heals me, by putting severed vessels back together, at which task the air and the pungency of oozing fluids would keep it from

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succeeding.” >! A similar intelligence operated in insects and plants, in the spider that wove its web, the stem that straightened itself towards the sky if bent towards the earth, the root that skirted a stone. “In sum, it is an intelligence that carries out virtually everything that we admire in plants, trees, and animals, and that it seems to me most philosophers explain rather poorly through pure mechanism.” 7” Cudworth was a theologian and Hebrew scholar; Le Clerc, a journalistic theologian; Stahl, a physician. Hartsoeker himself, however, was a physicist who had started out as a Cartesian, and his abandonment of mechanism was thus more serious. Indeed, as we have seen, his conception of science was that of a Newtonian who had not understood Newton. But the movement of his thought would carry him still farther, far enough indeed to demonstrate that Leibniz’s fears were well-founded. Hartsoeker’s Recueil de plusieurs piéces

de physique, published in 1722, again took up the question of the generation _ of the crayfish pincers, as well as the origin of spermatozoa fashioned in the testicles, “as if, so to speak, in laboratories suited to that” by “an intelligence of whatever sort resides in a male animal.”?°? And above all, despite his “of whatever sort,” Hartsoeker returned once more to the problem of the nature

of this intelligence. He had at first thought it different from the thinking soul. But how could these two souls communicate with each other? I resolved finally to conjecture that there is only one soul in us that does everything. Moreover, I conjectured that this soul might well be nothing other than a portion of

the soul of the universe, which I called in my works on physics the first element or perfectly fluid substance, and which, having extension like matter—although otherwise essentially different from it—can impel bodies and be impelled by them, give them movement and receive movement from them; and I resolved all the more readily to make this conjecture in that I freed myself thereby from the great difficulty that men have always had in conceiving how communication can occur between soul and body. In this way, I conjectured that the soul is spread out through the whole body.?34

This was therefore the same soul that felt and thought through animal spirits, that moved the heart, gave rise to the peristaltic movements of the arteries and intestines, cared for the body when it was sick, and fashioned the spermatic animalculi containing the preformed embryo. How did it do all that? “Without knowing if and how it does it, I will say that I have no idea, and that I despair even of ever being able to say something the least bit satis-

factory about it.” How could this soul think? I have no other answer than that it is a wish and gift of God, who is infinite and all-powerful; and I would ask, in turn, what idea one can hold of a spiritual or im-

350 THE SCIENTISTS PHILOSOPHY material substance without extension, and how it can think. For when people speak to me of a spiritual substance, I seem to hear merely words to which they attach no distinct idea; and when they say that it is an immaterial substance, they are saying what it is not, and not at all what it is, so that I am no further along after their answer than if they said nothing.?°

It was 1722: Voltaire had not yet discovered England, Locke, and Newton.

No doubt Hartsoeker’s thought had nothing absolutely original in it. His efforts to conceive of a vital soul with extension but without matter, a soul he defined as “completely pure fire,” recall Gassendi and Thomas Willis, with

| whom he was familiar.?3° They recall Helmont as well. Moreover, the materialist conception of the human soul was not that unusual then. But without denying the importance of the influences he may have felt, we must grant Hartsoeker the merit of a personal and meaningful evolution. He was first of all a physicist who sought to fill in the gaps in mechanism. To this end, he had to free himself from Descartes, which he was unable to do without abandoning the notion of clear ideas, without destroying the distinction between soul and matter, and without ending up, willy-nilly, with materialism. For who would accept in 1722 that a substance with extension, which could “impel bodies and be impelled by them,” “differs essentially” from matter? It is matter that thinks, thanks to “the wish and gift of God.” Locke had been content to say that such a thing was not impossible. For his part, Hartsoeker calmly asserted it and even denied that a spiritual substance was conceivable. The Journal des Savants diffidently covered its face,*°” and the Académie des sciences maintained its full coldness with respect to an “associate” whom it already deemed overly troublesome.’** Three years later, when it was necessary to deliver Hartsoeker’s funeral eulogy, Fontenelle cast a modest veil over these regrettable vagaries.**”

Hartsoeker had spent part of his life combating Newton. In the end, he linked up with some of the essential positions of English thought and it was inevitable that he would arrive at that point from the very moment he abandoned integral biological mechanism and the preexistence of germs. The mechanist system was too internally coherent for one to be able to remove a part without wrecking the whole. To introduce an “intelligence” capable of

acting upon matter was to renounce the “clear and distinct” ideas that one might hold of matter and to hand oneself over to the arbitrariness of God's unintelligible gifts. Starting out with mechanism and preexistent germs, and ending up with a “first element” that was extension, which thought and orga-

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nized matter, Hartsoeker had in his fashion covered half of the road leading from Malebranche’s mechanism to Diderot’s universal sensibility. Despite official condemnations, these ideas had a good chance of resonating with at least a portion of public opinion, more sensitive to the weaknesses of mechanistic explanations than to their intellectual merits. That there existed a sector ready to abandon the notion of clear ideas seems to be proved by the posthumous publication of two works by Frangois-Marie-Pompée Colonna, the Principes de la nature and the Histoire naturelle de lunivers. The natural son of an Italian prince, Colonna, who had died at nearly 82 years of age in 1726, was not an orthodox spirit. He was an admitted disciple of Paracelsus and adhered to the least rational aspects of his master. He was an atomist but offered a highly pertinent critique of mechanism.?*° Like everyone else, he refused to grant an organizing power to chance and did not even see how a plant or an animal could live mechanically.”4! To assume that a

plant chose the elements appropriate for its nourishment thanks to a sifting of particles carried out in the roots appeared absurd to him: sufhciently small corpuscles would still find their way through the holes in the sieve, no matter what their conformation.?42 For Colonna, assimilation was a chemical phenomenon, a transmutation, that required the intervention of a certain “virtue” or “spirit,” whatever might be said by “the modern philosophers who would have it that everything is carried out through a certain mechanism made up of certain molds that they have forged in their own brains.” 7? In attacking biological mechanism, Colonna clearly seems to have been going after integral mechanism of Epicurean inspiration and thus to have been moving towards the theory of the preexistence of germs. Nonetheless, he did not accept preexistence either: “I am positively not adopting this extravagant opinion; I am simply astonished that those gentlemen who wish to account for everything through mechanism, unable to say how the tiny plant is produced from the seed, have had recourse to such wild imaginings.” 744 In fact, for the mechanists, preexistence was merely a means of “cleverly getting out of a fix.” ?* But all the evidence was against them, starting with Harvey's observations that prevented our accepting the existence of eggs in viviparous animals, as well as the role of sperm cells.**° There was no preexistent germ,

and we had to return to the opinion of the ancients: the hen fashioned an egg and the cock provided a formative agent or form.?4” Malpighi’s observation on the preformed chick was bothersome, but one could explain it by assuming that the egg began to develop in the body of the hen, and that this

352 THE SCIENTISTS PHILOSOPHY development, interrupted at the moment of the laying, started up again during incubation.?4* If, moreover, experimental knowledge made epigenesis a requirement, that in turn required “an artisan, a painter or sculptor.” For after all, the egg was obviously inert. “And as the end result, are you not surprised to see emerge a cock that moves, that struts about, that loves and hates; that fights out of pride, that loves out of sensuality, and that acts in its association with hens in a way that could serve as a model for many men?” ?*? How, moreover, were we to explain instinct in birds, which “philosophers who see animals as machines pass over lightly?” ?°°

We had then to believe that the male seed contained “a certain spirit of celestial fire,” ?*! a “non-elementary” heat,”°? a knowing being that organized

the development of the embryo, and whose existence all the philosophers, with the sole exception of Epicurus, had accepted.”** Now, this principle of organization could not be restricted to living nature alone. Minerals also vegetated and grew.>4 They must therefore possess souls. No doubt this soul was “enclosed in them without being able to express feeling, and therefore without perceptible action upon our senses.” But perhaps they suffered in there, and perhaps this was the hell of the ancients!*°? A Jesuit consulted on the merit of these ideas, Father Louis-Bertrand Castel, was instantly disquieted, judging it dangerous to grant souls to plants and stones: “Be careful,” he said, “lest you make God himself the soul of the world.” °° This was to be precisely

Diderot’s reaction to the ideas of Maupertuis. But Colonna, faithful in this to the spirit of Paracelsus, saw no major problem in making God the soul of the world. The essential for him was to admit that everything came “from the being upon which all depends, whether one calls it God, Natura naturans, or the Soul of the world: for these names merely mean the same things.” *?” It is,

in any case, worth noting that Father Castel recognized without debate the necessity of going beyond mechanism: “Mechanism is inadequate, he said, “but it is necessary, and constitutes half of the complete system of the uni-

verse. ?°8 |

In the last analysis, it was merely a question of knowing what form one would give the unknowable. “There is no shame in admitting that the ultimate principle of all the wonders of the universe is unknown to us,” said Colonna.2*? Official science said no more than this. But for science, this unknown was the direct action of God at the moment of Creation. For Colonna, as for Cudworth, Stahl, and Hartsoeker, it was a currently active principle hidden in nature. Concerning the essence, the divine or other origin of the principle, its mode of action, debate would go on to infinity, and science did

Problems with Preexistence 353

not seem to have much to gain from it. Still, in light of the simple fact that | this active principle was currently present in the universe, nature ceased to be a passive mechanism. Instead of discovering in nature only machines set up once and for all, the scientist would be able to look for sequences in phenomena that occurred in time, and whose laws were accessible even if the underlying cause remained hidden. A science became possible that was not merely a catalogue of things but a knowledge of their genesis. It is surprising neither that this search for a new science was first undertaken in the area of the generation of living beings nor that its first manifestation was a rejection of the theory of the preexistence of germs.

Conclusion to Part II

IN 1670, Descartes had been dead for twenty years, and Cartesianism was just beginning its conquest of the scientific world. In 1745, the great venture of the Encyclopédie was on the point of being launched, and Enlightenment philosophy was taking hold of European thought. The interval between these two summits of French intellectual life may be considered one of those transitional periods in which the movement of ideas counts for more than the ideas themselves. Above all, moreover, one may enquire whether this period constituted a real unity. The end of the seventeenth century seems identifiably marked by the apogee of Cartesianism. The first half of the eighteenth century saw the birth and self-afhrmation in France of empirical and Newtonian thought. Under these circumstances, and even without taking into account the infinite variety of individual positions, it may seem impossible to speak of a period or a mentality. Even limiting one’s perspective to scientific questions alone, how can one lump together the followers of Descartes and the Newtonian precursors of the Encyclopédie? Moreover, if it is true that scientific activity both reflects and influences intellectual life overall, is it not an illusion to attempt to find unity in a confused period, marked primarily by battles between irreconcilable adversaries?

The force of this objection must be recognized. First of all, however, from the perspective of this study, the exceptional scientific activity throughout these 75 years prevents us from considering them merely a period of transi-

| tion. On the other hand, and again from our perspective, the period’s unity is demonstrated in striking fashion by the birth, triumph, and survival of certain scientific theories that the following period would peremptorily again call into question. Now, these theories rested upon facts, true or false, well

Conclusion to Part II 355 or ill interpreted; but also, and perhaps especially, upon a certain scientific mentality that brought with it, or posited, certain philosophic and religious attitudes, at a time when philosophers were often scientists and when scientists did not abstain from philosophizing. For all that, it is not a question of freezing in artificial immobility an era that was one of movement. If this period possessed a distinctive spirit, we shall find it in the underlying tendencies that oriented the movement of ideas, and not in the stability of the ideas themselves.

THE THREE DOCTRINES of generation that were to rule biology until 1745, and that gave this period its aforementioned unity, were formulated before 1680: Johann van Horne and Régnier de Graaf had afhrmed the existence of viviparous eggs; Leeuwenhoek had discovered spermatozoa; and Swammerdam, Malebranche, and Perrault had given definitive form to the theory of preexistent germs. The three doctrines would subsequently be disseminated, become established, clash with one another, and encounter new difficulties; but they already existed, and nothing would be added to them. Now, these doctrines, or at least two of them, by their mere existence called into question the nature of the “Cartesian spirit” whose hegemony over the science of the period is too often uncritically assumed. Ovism was in no way incompatible with Cartesian thought, and Descartes had not misread the importance of anatomy, inquiry into which was crowned by this doctrine. But nothing was less Cartesian than Leeuwenhoek’s genius, a genius for unpremeditated observation, which abandoned itself to serendipity and delighted in the spectacles offered it without bothering to make systems of them, ingenuously admitted its ignorance, and found in that very ignorance the opportunity to celebrate the glory of God, all-powerful Creator of incomprehensible marvels. Apparently Leeuwenhoek was entirely ignorant of Descartes, of systematic doubt, of clear and distinct ideas, and of universal mathematics. He knew only his microscopes, his animalculi, and the scientists of London, who were easy to alarm and at times difficult to convince. Without intending to, and probably without realizing it, Leeuwenhoek was carrying on his research as if Descartes had never existed. Others abandoned Descartes without the excuse of ignorance. By adopting the preexistence of germs, Malebranche renounced more than just the most debatable portion of his master’s work. The moment he took away from nature and gave to God alone the power to form living beings, he destroyed all of Cartesian science. As soon as it escaped from the laws of motion, the

356 THE SCIENTISTS PHILOSOPHY formation of beings escaped the human mind, and with respect to this question, science was no longer possible: men found themselves confronted immediately with the mystery of God. That mystery, which Descartes had at the same time thoroughly respected and removed from the purview of science, Malebranche claimed to usher back in by affirming that God obeyed an order, that He acted only through simple and general laws, and that man could at least partially know the designs of God, thanks to a knowledge of final causes. But it was a simple matter for Arnauld to reply that by crediting preexistent germs, Malebranche was renouncing the simple and general

laws, and that the order to which he wished to subject God was merely a human fantasy. Régis was more logical in maintaining that nothing, after all, prevented God from directly forming those infrequent beings that we called monsters because they shocked our limited understanding. As soon as one left nature behind, one entered upon the unknowable. What still remained of Cartesian science outside of mechanism, a mutilated mechanism allowed only to oversee the functioning of the living ma-

chines that it was incapable of constructing? Moreover, this incomplete mechanism was already close to becoming an act of faith. Malebranche acknowledged that one could not apply it intelligibly to the simplest functions of animal economy. Leibniz afhrmed that the living being was a machine in each of its parts, and so forth, so that eventually mechanism was lost in

God. Perrault, in turn, did not hesitate to say that without a soul to direct the bodily functions, the laws of motion were as powerless to give life to an animal as to form it. Thus he simply ignored the barrier that Descartes had

established between thought and extension. ,

Nonetheless, Cartesianism was only beginning to conquer the scientific world. Descartes’s cosmology, the system of vortices that Fontenelle set forth in his Entretiens sur la pluralité des mondes, was to enjoy a 50-year reign. France became “entirely Cartesian under the reign of Louis the Great.” One could hardly imagine a more complete nor, in appearance, a deeper triumph. And yet, even before Descartes’s physics was attacked by Leibniz, Huygens, Newton, or Malebranche himself, well before the vortices, the plenum, and subtle matter were denied in France in Newton’s name, Descartes’s entire system of thought found itself called into question by the destruction of his embryology. Contemporaries thought, no doubt, that they were doing their master a favor by unburdening his system of its most vulnerable—because most theoretical—component. But as this component was, precisely, the most perfect expression of the Cartesian ambitions, it could not be aban-

Conclusion to Part II 357 doned without damage to the entire body of Descartes’s thought. Thereafter, one could, of course, continue to defend the vortices: of the very spirit of

Cartesianism, there remained only what had become or had always been common to all of the new science—the demand for clear and distinct ideas, the search for evidence, which was, moreover, on the verge of moving from rational evidence to the evidence of the senses, and finally to the idea that the universe was simply a vast machine. But the universal mathematics, which was to allow man to reconstruct the world starting from first principles, just

as the world had constructed itself starting from matter and motion, was henceforth no longer part of scientific discussion. What had triumphed over Descartes, long before Newton and Locke, was

the spirit of the new science, embodied in Boyle and the London natural philosophers, and represented in France, although with less purity, by the young Académie des sciences. This was a composite mentality, an odd grouping of Epicureans and chemists, skepticism and Augustinianism, respect for the Bible and passion for observation, a complex of Christianized Gassendi and tamed-down Helmont. Each of these major tendencies of the new spirit would contribute its share to an ineluctable evolution, which, already begun

in 1680, would lead to the mentality of 1745 despite the resistance of those, who, once having set the evolution in motion, attempted to contain it within limits they judged reasonable.

WHAT CAME under attack first from every side was, precisely, the power of reason, along with its right to know the world. Traditional skepticism, which had always looked with suspicion on the rationalistic audacities of Des-

cartes, was grounded in a certain number of classic arguments proving that man, as such, cannot arrive at the truth. Resting, so to speak, upon an internal critique of the human mind and its products, this skepticism could lead to opposing philosophic and religious opinions, agnostic or fideistic, but on the scientific level it demanded humility before the facts and prudence in framing conclusions. Fontenelle unquestionably came directly from this tradition, and his circumspection did not date from his initiation into the scientific disciplines. But Boyle came from it as well, and in this is seen the ambiguity of the Gassendist legacy. The progress of observation would soon bring stunning confirmation to this skepticism grounded in principle. One may even wonder whether the temporary multiplication of extraordinary tales in the earliest scientific periodicals does not signal the triumph, at least momentary, of a doctrinal skepticism for which anything was possible, especially the implausible.

358 THE SCIENTISTS’ PHILOSOPHY The end of the seventeenth century was not, however, the end of the sixteenth; reason was still a powerful instrument of critical thought, and the taste for order remained strong enough to throttle the temptation to anarchy. Still, even when verified, observation was already multiplying the number of unexpected discoveries, which daily widened the distance between reality and the constructs of the human mind. The microscope, above all, revealed

the existence of a world not dreamed of by Descartes. This time, human reason was under attack from outside; it was transcended and humbled by nature rather than by itself. There was, to be sure, nothing absolutely new in this, and the old skepticism had long known that there were more things under heaven than our philosophy could conceive of. This time, however, the breadth of the phenomenon was such that the scientist, having for a while believed that he could enclose nature in his clear and distinct definition, began to look at it anew with religious awe. Traditional skepticism had not liked this feeling very much, even if it had not been completely ignorant of it. It had possessed in particular an entire arsenal of arguments and gibes against the all too well-known marvels of the human body. But it now found : itself deprived of ammunition by these astonishing beings that had nothing in common with man, by microscopic creatures, by the wonderful insects. It found itself obliged to take God seriously, as did Fontenelle, or to take refuge in philosophic positions resolutely foreign to the discoveries of science. Religious, if not Christian, skepticism was the most widespread of these positions, and among the proofs of the existence of God, the one most commonly employed—at the expense of rational proofs—was the proof resting upon the marvels of nature.

While skepticism was denying the power of reason, and while a constantly expanding knowledge of nature was making a rational explanation of it ever more improbable, the influence of Augustinian thought was tending to negate the very object of science. By refusing all efficacy to secondary causes, Malebranche reduced phenomena to a kind of play of appearances.

God alone was the real and direct cause, and one had to assume that God followed an order, otherwise science was no longer possible; for nothing, out-

| side of His own wisdom, could prevent God from making a stone float on the surface of water. Science, however, ran the risk of taking God as its object rather than nature; and it was very chancy to define the divine order. Without going so far as Malebranche, those who accepted the preexistence of germs took all activity of its own away from nature. Here again, observation interfered. The mode of reproduction of insects, the complexity of their

Conclusion to Part II 359

organization, the perfection of their instinctive acts, forced the scientist to consider them as machines brought forth directly from the Creator's hand, built in their entirety and wound up, so to speak, by the supreme Clock-_ maker. It seemed implausible that such perfect beings should have a natural origin. Between God and phenomena, the thickness of nature, if it could be expressed thus, was less and less great: “. . . and I sensed/Creation trembling like a veil,” the scientist might then have said, anticipating Victor Hugo. Augustinian thought, so active in the seventeenth century, could not have been unknown to philosophers or even scientists. Still, it would surely not have acquired such importance had it not profited from the crisis of mechanism. Once the initial reaction of enthusiasm had been played out, it was finally seen that the laws of motion through which the formation of living beings was to have been explained were reduced to very little: impenetrability, inertia, the laws of encounter, elasticity. To assume that elementary particles subjected to these rules alone could meld together so as to compose an animal was sheer madness. Descartes himself had been obliged to grant his elementary particles very complicated shapes, with results that were no more convincing. Epicurus’s atoms had obeyed the laws of motion, and yet no man of good sense was able to accept that the organization of the universe could be the result of their collisions and ricochets. The laws of motion did not ex-

clude chance, and therein lay the nub of the problem —for it was impossible to believe that an animal could be formed through “a fortuitous encounter

of particles.” Into a nature that mechanism would have abandoned to “blind , chance,” into a universe that general and simple laws could not have drawn out of chaos, God had introduced the necessary order and “design,” by building the machine with His own hands, down to the very least details. Then, like a clockmaker who has completed a clock, he had set the pendulum in motion, and the machine functioned independently according to the laws of motion. But the gearings were so carefully structured that there was no longer room for chance, and the mechanism executed perfectly what it was fashioned to do. By sacrificing the part, it was believed, the whole could be saved: mechanism could be maintained by scrapping what was indefensible in it. What people wanted above all to preserve was the intelligibility of the world, which mechanism alone could guarantee. Most great minds at the beginning of the eighteenth century wanted to assure reason an active role in the knowledge of nature. For Malebranche as for Leibniz, God obeyed an order, He did not act without sufficient reason, and this order, this reason, although infinitely beyond man, was not entirely inaccessible to him. Great naturalists like Mal-

360 THE SCIENTISTS PHILOSOPHY pighi, Tournefort, Vallisneri, and Réaumur thought that there was a Godgiven order in nature that science could reach. Malpighi believed in general laws and the fruitfulness of reasoning by analogy; Tournefort judged that plants were divided into types in nature, as in his botanical system; Vallisneri was convinced of the simplicity, generality, and uniformity of natural laws,

and declared nature incapable of presenting anything inconceivable to the human mind—hence the critical role he attributed to plausibility. Réaumur, at least for a good while and perhaps until Bonnet’s and Trembley’s discoveries, believed in the value of analogy and plausibility and condemned the abuse of specific final causes, which tended to compromise the unity of the divine

order. For all these philosophers and scientists, it was understood that the ‘universe went infinitely beyond man because it was a divine creation; but also that it obeyed an order whose nature was not essentially different from that of the human mind, which could therefore reach within it, however partially. The position of Fontenelle is less certain; with respect to Tournefort’s botanical classifications, for example, he sometimes seems to have been tempted to consider science a purely human construct without a real grasp of its object,

but most often he judged man capable of one day putting together enough observations to reconstruct the essential mechanism of the universe.

NO w, this middle ground, adopted by most of the French scientists, would soon be made uninhabitable by a new English assault. It was easy enough to show that holding it depended upon gratuitous, and even contradictory, convictions. Even while reducing man to nothing in relation to God, the proponents of the middle ground purported to impose on God an order that was in fact only a human idea. Notwithstanding Fontenelle’s recommendation of a “wise Pyrrhonism,” it continued to be argued, in the name of “clear ideas,” that one could define matter and its attributes. Like Arnauld and Régis in dealing with Malebranche, Clarke in dealing with Leibniz recalled that we were ignorant of everything concerning the relationship between God's

wisdom and His freedom; that we had no right, if we were to avoid fatalism, to prevent God from intervening daily in His Creation; that to label a force an “occult quality” did not nullify its existence, and that God was quite free to give matter whatever quality He pleased, without having to find out whether this agreed with our trivial reasoning. It was not enough to say that God had created everything: one had to admit that He had created and governed everything according to a plan, towards ends and through means

Conclusion to Part II 361 that entirely escaped our understanding. Fontenelle and his colleagues were ill situated to reply. They had made the first concessions, the ones that had set the thought of the time in its entirety on the track it was now following. They had mutilated mechanism, accepted final causes, and brought God “as if into the machine.” When one brings God into science, it is impossible to assign Him a place: one is soon obliged to hand over everything to Him, and science is no longer possible. Moreover, it became all the more difficult to reply, in that the discovery of nature, pursued uninterruptedly, kept making the order whose existence was being affirmed less and less apparent. Anatomical investigations, so satisfying to the sense of order, were beginning to lose their wind. Other techniques were needed to reinvigorate them, and the temporary results of these brilliant investigations were such as to bar the researchers from discovering the secret of life, whose mechanistic character was now called into question. What was worse, by studying teratisms, anatomy discovered unexpected perfections, evident marks of wisdom in these anarchical products. The scientists’ attention was more and more drawn to natural history, however, where pure observation ruled, and above all to insects. And the research carried out in this area brought increasingly dazzling demonstrations of the incredible wealth, the infinite perfection, but also the invincible strangeness of God’s work. One could describe insects, one was obliged to admire them—but one could not understand them. Enormously distant from man, they implied a plan and a design in Creation that reason decidedly could no longer comprehend. The order of nature vanished into divine mystery. Teratisms, like insects and all that lived, bore the stamp of a strictly unknowable God, of a God foreign to man. Man might then wonder what his place was in the universe, seeing that the lowest and most despised of creatures surpassed through the miracles of their organization and instinct the fair ordering of human anatomy, celebrated for so long, and the cleverest accomplishments of the intelligence in which man took such pride. The old skepticism was winning out: man was decidedly no longer anything in nature. But nature was God Himself. Or rather, as Fontenelle so admirably put it, nature had become the stage of the Paris Opera. No one, however, could go backstage, because the back-

stage no longer existed. The fanciers of machines, if any were left in the hall, might certainly continue, propped up in their seats, to speak of pulleys, ropes, counterbalances: it was a habit they could not be cured of. In a corner, a few foreigners were uttering bizarre terms: “attraction,” “soul,” “plastic

362 THE SCIENTISTS PHILOSOPHY natures.” They were looked at askance. But as the scenes progressed, new turns of phrase, unexpected descents of divinities from above defeated the imaginations of the cleverest among the mechanically minded. The others repeated their unintelligible formulas with self-assurance. Would it not be better, finally, to renounce all speculation, to abandon oneself to the spectacle, to the wealth of costumes, the beauty of the scenery—to admire without ulterior motive the ingenuity and splendor of the supreme director? The trouble was, however, that the myth of the Opera was somewhat reminiscent of the myth of the Cave. This spectacle was one of shadows, and we were tied to our seats. We could no longer be quite sure whether we were the guests or the prisoners of the invisible impresario. This was the point, precisely, on which minds were divided. The apologists of Christianity turned the wonders of nature into a privileged proof of

the existence and wisdom of the Creator. But it was not enough merely to demonstrate that God existed; it was also necessary to prove that man was precious and dear to Him, that He had intended man to be the master of Creation. To the traditional glorification of the beauties of the human body, English religious thought, soon imitated on the Continent, would add all the advantages that man drew from the organization of the world: the regular cycle of the seasons, the night that brought rest after the fatigues of the day, the calm lamp of the moon that made up for the absence of the sun, the fortunate saltiness of the seas, the precise amplitude of the tides. The tireless bees, the heavy fleece of the sheep, the obedient and faithful dog: all had been created for man, for his well-being, for his innocent pleasures, and for his edification. From this whole body of writing, whose spirit Fénelon shared to a large degree, and with which Jean-Jacques Rousseau was not unfamiliar,

there wafts a scent of rustic happiness. Far from the city and its unhealthy atmosphere, in the park of a fair chateau and under the gaze of God, the abbé Pluche’s characters enjoy varieties of happiness as virtuous as they are instructive, while admiring at the same time the bounties of Providence and the advantages that the ingenious activity of man has drawn from them. Thus came into bloom an innocent optimism very unlike that of Leibniz, an optimism nourished by the sweet emotions that contemplation of a benevolent nature engendered in a pure and sensitive heart, rather than the abstract satisfactions procured by a vision of the universal order. Thus there came about a return to the “God perceptible to the heart,” who was, however, that of neither Pascal nor Malebranche. Just as science unsystematically assembled the astonishing

Conclusion to Part II 363 “mechanisms” at work in nature, so religion multiplied the particular “attentions’ paid by Providence, permitting man to feel secure in a world made for him, and that he had given up trying to understand. God watched over him paternally: “Estote sicut infantes” [You must become as little children]. The deist, however, was scarcely tempted by this idyllic vision of creation. If he recognized the existence of a God, nothing proved to him that this God had created the world for man. Indeed, everything invited him to believe the contrary. In this, deism was the natural heir of the old skeptical tradition, and science brought nothing that was absolutely new and unpublished. First off, however, by permitting Christian thought to extend and clarify its claims, science underlined what was gratuitous in those claims, if not what was ridiculous in the eyes of common sense. It had not been unreasonable to maintain that human anatomy bore a relationship to the use of human intelligence. It became more serious when it was claimed that the moon existed purely as an aid to navigation. Moreover, science showed that the divine wisdom had taken no less care with insects than with man, and it was not likely that God had created the mosquito purely for the edification of eighteenth-century naturalists. Finally, it was becoming increasingly evident that the divine plan of Creation was unknowable, and that man had to be suffering from insane pride to go on claiming he was the center and the justification of a universe that he did not understand and in which he occupied merely a tiny space. Little concerned with finding in nature the manifestations of a Providence that he did not believe in, the deist had the impression of thus economizing on a considerable number of absurdities. At the same time, he was able to preserve an image of God worthy of Him. He was better protected than the Christian against the temptation of misusing teleology: his God remained the supreme Intelligence, the Creator and the sovereign and impassive Master, the God of the universal order and of general, immutable laws, the God who was in no way obliged to lower Himself to the level of man, whom He took little note of and from whom He remained infinitely distant. This distance, moreover, not only rendered improbable the attentions attributed to Providence; it rendered utterly implausible the central dogma of Christianity, the mystery of the Incarnation, which the theologians themselves were experiencing so much difficulty in justifying, falling back most often on endless discussion of the historical arguments. God’s transcendence overwhelmed the human mind, made it impossible to take seriously a Revelation of any sort whatever, and abandoned man to his destiny under the rule of eternal laws

364 THE SCIENTISTS PHILOSOPHY dictated by an indifferent Creator. Given over to himself, man would be able to take advantage of his being, or else rebel. He would in any case no longer be able to find his happiness in the contemplation of a nature that knew him not. What united everyone, however, deists and Christians alike, was concern

to use to best purpose what had been given man. The desire to take advantage of scientific discoveries was certainly not new in 1730. Colbert had expected the Académie to do more than observe the stars, and Louvois had been quite willing to remind it that it was working first and foremost in the king’s service. The birth of industry gave rise to technical problems in need of solutions. But the growing importance given to practical research and the increasingly urgent concern to do something directly useful, even in the study of insects, were all part of the spirit of the time. As science judged itself less capable of understanding the world, it became more concerned with exploiting what it knew; as it repudiated abstract systems, it turned more and more to concrete technologies. Practical research, far from encouraging or abetting conquests of theoretical knowledge, served rather as a consolation for its failures. For the abbé Pluche, man hewed closer to the Creator’s intentions in constructing hives or ships than in measuring the distance of the planets. For the “worldly” Voltaire, man was wisest when he worked towards his own happiness.” In any case, useful technology won out over illusory knowledge.

THE HISTORY of the life sciences from 1670 to 1745 is, then, the history of a long battle waged by observation against aprioristic mechanism, a battle whose outcome was a foregone conclusion, and whose end saw the ruin of mechanism. Official science, which remained faithful to it, no longer con| ceived of it as anything more than a metaphysical principle, which in practice it confused with the unknowable order of God. Heterodox science, given progressively more of a hearing, had reintroduced into nature non-mechanical

principles that exempted it from having to refer everything to God, but that were unintelligible and accepted as such. Clear and distinct ideas were a dream from the past, and facts constituted the only definite acquisition: poetic justice inflicted on Descartes’s pretensions to found an a priori science! The reaction, however, went so far that it called into question the very possibility of science. For Pascal’s formula was true on the level of knowledge too: “Unfortunately, he who wishes to play the angel plays the animal.” * Roger put “worldly” (mondain) in quotation marks as a reminder of Voltaire’s early Epicurean poem “Le Mondain” (“The Worldly Gentleman”). —Tr.

Conclusion to Part II 365 Among the scientists who had seen the old rationalism slowly sink under the blows of observation, skepticism reigned. Man could not know the intimate order of the world, therefore he could know nothing except unrelated facts. The notion of a positive science that would be limited to phenomena, but that would collect them in order to derive laws from them, seemed as yet unknown: the lesson of Malebranche and Newton had not yet been understood. Stunned by an avalanche of new facts, the scientist was still at the stage of logging his riches, without much hope of getting to the end. We cannot ask more of him. Lacking a conception of positive science, scientific thought was still subjected to the old oscillation between dogmatic rationalism and empirical skepticism. The triumph of the latter was all the more complete in that empiricism had reached a hitherto unknown degree of certainty and of observational sophistication, and inasmuch as the thought of the time, ill prepared for such a test, was not yet able to integrate observation into a balanced theory of knowledge. The old philosophy, which confused respect for facts with skepticism, and the desire to reason with aprioristic dogmatism, still reigned. As much as observation, which nourished it, traditional skepticism had triumphed over Cartesian rationalism. Vanquished as a form of rationalism, biological mechanism was equally done in as a form of mechanism. The geometrical vision of the living being that it proposed was too crudely conceived to be defensible for long, and the clarity it claimed to introduce was quickly revealed as an illusion. Not only was it deprived of the aid of chemistry, it even tried to reduce chemistry to its own uncertain and ultimately rudimentary laws. Above all, however, the image that mechanism presented of the living being was profoundly antibiological and displayed a mentality completely foreign to the very nature of life. This image, that of a machine composed of inert and passive workings, capable only of transmitting motion received, led inevitably to a search for justification and purpose outside the machine. A machine exists only by virtue of the mechanic who has built it, and for the use he expects of it. It is fully explainable only from outside, and one cannot understand a clock without knowing its purpose. On the contrary, on the level of science, the living being is itself its own end, its own “in-view-of-which” cause, as Aristotle had put it. It serves no purpose except to live, and this internal finality is the only one that the biologist can allow. Now, mechanism cannot account for an internal finality, whereas, in fact, it requires an external finality, a design of the mechanic who confers an order on the construction of the machine. In this way, biological mechanism turned the scientist away from his true object, the

366 THE SCIENTISTS PHILOSOPHY living being, to lead him towards an unproductive meditation on the designs

of the Creator. Quite naturally, mechanism had to stumble when it confronted the difficulties posed by reproduction for, as Fontenelle (and Kant after him) noted, there exists no clockmaker clock. Quite naturally, thinkers were obliged to proceed backwards from the machine to the mechanic and to arrive finally at preexistent germs, a theory that revealed one of the underlying tendencies of mechanism, while at the same time mutilating it. As for the internal logic of this evolution in ideas, it expressed in its own way what was perhaps the fundamental feature of the period we have been studying: the irresistible drive impelling man to escape himself in order to annihilate himself in God or to merge with tangible nature. The scientific mentality of 1745 did not disappear overnight. The number and importance of the facts revealed by the assiduous practice of observation allowed certain scientists to cover up or to trivialize the weaknesses of an intellectual position that was not always either as clear or as self-aware as our analysis might make it seem. After Cartesian dogmatism and the abuse of arguments not grounded in reality, science had to learn once again the virtues of doubt, humility, and patient observation. Provided it was well understood, the lesson had value, and would not go to waste. Finally, the agreement between science and faith, however dangerous its premises may have been for both, was able to sustain many Christian scientists who did not foresee the new and risky paths onto which this ephemeral agreement would lead Christianity. For all these reasons, fortunate or unfortunate, the mentality of 1745 would survive even far beyond the eighteenth century. After 1745, however, a reaction began to take shape. Fashioned by philosopher-scientists, or philosophers concerned with scientific problems, this reaction would have consequences far beyond the confines of science proper. Like the thought it was combating, the new scientific philosophy was to rest upon a general conception of man, nature, and God.

The Philosophers’ Science

(1745-1770)

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Precursors and Mavericks

THE NEW biological thought that appeared in 1745, and that would henceforth set itself up in opposition to that which I have been describing, is in many respects still alive, and at least a portion of nineteenth-century intellectual history was motivated by the irreducible opposition between these two mentalities. The impassioned debates that pitted Cuvier against Geoffroy Saint-Hilaire, the vitalists against the mechanists, Pasteur against the defenders of spontaneous generation, and Darwin against the opponents of transformism, reveal, despite the diversity of the issues, the arguments and the scientific theories in question, the persistence of a basic conflict between two attitudes that were irreconcilable both because of their philosophic nature and because they were rooted in the very depths of the participants’ being. If, then, we were to pursue our investigation as we began it, attempting to give an overview of scientific activity and to bring into focus the dominant ideas that formed the intellectual framework of the scientists’ work, we would find it very difficult to set chronological limits. The history of discoveries regarding generation would no doubt provide us with some boundaries, but these discoveries would apply only to certain areas of research. Moreover, we would have to progress well into the nineteenth century in order to find an important date: it was in 1827 that Ernst von Baer revealed his discovery of the ovum in the ovary; only in 1875 would Oscar Hertwig observe the fertilization of an ovum by a sperm cell, thus putting an end to all debate on the nature of the “spermatic animalculum,” which was scarcely better understood in 1850 than in 1745.

In any case, it is clear that this enquiry has to shift its orientation at

370 THE PHILOSOPHERS SCIENCE this point. The thinking of the biologists and naturalists of the first half of the century evoked problems that are outside the purview of science as we understand it today. The unity of “natural philosophy” has to be respected, however, as the partisans of the new science did in their way, by combating the thought of their predecessors on all levels. The generation of animals might seem to have been forgotten in these debates involving primarily God, nature, man, and knowledge. We shall see that in reality it was not. The new philosophy called for epigenesis every bit as imperiously as the old had called for preexistence. In any case, the debate was taking on an increasingly philosophical cast. The history of biology must thus take second place here, and scientific theories and discoveries will be alluded to as such only as a func-

tion of the philosophical debate; as a result, certain of these theories and discoveries, such as those of Caspar Friedrich Wolff, will remain marginal to our concerns, despite their importance. What I wish to examine now is the thought of the scientists and philosophers who were contributors to or contemporaries of the Encyclopédie, and who as a group rejected the scientific mentality of the first half of the century, along with the theory of generation that was an essential part of it. Furthermore, the method adopted in the preceding pages, which led to a

focus on intellectual currents rather than men, can no longer be employed here. For although the undertakings of the new philosophers shared a common spirit, broadly speaking, they nonetheless remained individual investigations, whose originality would be betrayed if they were grouped together for purposes of study. We shall better be able to grasp the innovators’ kinship if we first examine them separately. The new biological spirit did not, however, emerge spontaneously, and a

rapid review of the major influences contributing to its birth is indispensable. These influences came not only from outside the purview of biology but even from outside the purview of scientific thought. It is not, in fact, irrelevant to note in this regard that the scientists and philosophers who were to give new direction to the life sciences had not for the most part had a naturalist’s or biologist’s formal education. Pierre-Louis Moreau de Maupertuis and Georges-Louis Leclerc de Buffon were first of all mathematicians, but both were concernéd with applying mathematics to “physics,” celestial mechanics, or probabilities, and both were disciples of Newton. Julien Offray de La Mettrie was a physician but also a philosopher, and Denis Diderot was and would remain a philosopher who confronted the discoveries and hypotheses of the science of his time with the demands of his individual ideas. It was these men

Precursors and Mavericks 371

from outside who would revolutionize biology and the natural sciences, to the great disgust of the “professionals” —Réaumur, Haller, Spallanzani— who felt themselves jostled by amateurs in their established ways and were often understandably exasperated by the inexperience and pretensions of the newcomers.

The first influence of note is that of Newton. It has already been alluded to in the preceding chapters, for it was multifaceted and contributed to opposing movements in French scientific thought. Its foremost role, already noted, had been to contribute to the ruin of aprioristic mechanism through

its assertion that God had created the universe in the form in which we saw it, and had launched the planets with His own hand; that He was still making His presence felt in this universe, imposing on matter the universal force of gravitation, which although inexplicable was attested by phenomena. Newton’s influence blended with that of English providentialist thought. In a foreword to the second edition of the Principia (1713), Roger Cotes had shown that Newton’s physics led to God because it accepted the void, whereas plenum physics led to atheism.’ Translating the Opticks in 1720, Pierre Coste emphasized the apologetic value of the “Queries” that concluded the work.’

Finally, the endless quarrel about attraction as an “occult quality” allowed everyone who wished to see in nature something other than a mechanism to gain authority from the example of Newton. In all this, Newtonian thought had aided in the formation of a scientific spirit that opened, as we have seen, onto the idea of God the Craftsman, the incomprehensible marvels of created nature, and the praise of occult qualities. In truth, the issue was one of knowing whether universal attraction should be considered a barrier preventing man from rising higher in the search for causes, or as an established fact on the basis of which a new mechanics was to be built. But what was attraction? Newton had at times seen it as an everrenewed gift of God to matter, and at other times (less frequently) as the possible result of an unknown mechanism. As early as 1713, Cotes had made it a basic property of matter.*? The prevailing skepticism, along with the influence of Locke, favored this position through the emphasis laid on the inadequacy of man to know the essence of matter and, consequently, to deny it one or another quality. More scientific minds, such as Mme du Chatelet and no doubt Maupertuis, would have preferred to grant attraction the character of a phenomenon as yet unexplained by mechanics but not unexplainable by definition.* This perspective, which Buffon possibly shared, did not however succeed in winning over the philosophers, who preferred, for the most part,

372 THE PHILOSOPHERS SCIENCE to make attraction an essential quality of matter. They found themselves impelled in this direction moreover, by the fact that universal gravitation had quickly escaped from the abstract and mathematical domains of celestial mechanics to invade other territories in the scientific world. Newton himself had displayed the use that chemistry could make of it at the end of his Opticks.’ After him, in England, John Keill and especially John Freind had set forth the principles and potential for an explanation of chemical phenomena through attraction. On the level of principle, there existed no serious difficulty, since it was accepted that bodies were composed of corpuscles that could perfectly well exercise attraction upon one another. In any case, the notion of “sympathies,” “kinships,” and “correspondences” among bodies had been a familiar part of chemical thought. Even after the triumph of mechanism, the vocabulary remained psychological, and Hermann Boerhaave conceived “between each particle of gold and each particle of royal water a virtue through which they love each other, unite with each other, and cleave to each other reciprocally.”° Experimentation gave grounding to this idea of “kinships,” and Geoffroy, who in 1718 constructed a “Table des différents rapports entre différentes substances,” ” claimed to follow, not Newton, but observation. Fontenelle had to give in, despite his mistrust of everything that might resemble attraction.® But Fontenelle’s misgivings very quickly found themselves simultaneously justified and outdated. In 1723, Jean-Baptiste Sénac published a Nouveau cours de chimie suivant les principes de Newton et de Stahl. As universal gravitation came progressively to dominate in celestial mechanics,’ Newtonian chemistry acquired more authority. Through it the idea became current that a definition of matter required the attractive force as well as extension and impenetrability. In this way, having veered away from its initial meaning, attraction had the effect of destroying the Cartesian concept of a purely passive matter incapable of providing itself with the motion that animated it. God was no longer necessary, and materialism could find a more solid foundation in science than the “tendency to motion” that had motivated Epicurus’s atoms. In addition, by arbitrarily isolating certain aspects of Newton's thought, it was possible to turn him into the master of all those who examined phenomena in order to formulate laws, renouncing any further search, whose pride would not limit itself to observation, but whose suspect humility refused to raise its eyes to the Primary Cause. It was no accident that the partisans of the new biology and of the new scientific spirit were nearly all Newtonians.

The role of Leibniz was scarcely less important, and the treatment his philosophy was accorded deserves careful study.’® After a period of neglect,

Precursors and Mavericks 373 Leibniz’s thought once again drew the attention of French philosophers after 1735, as much because of Caspar Friedrich Wolff’s success as through the investigations of Jean-Louis-Samuel Formey and especially of Mme du Chate-

let." The results of this renewal of contact might seem rather slight, and Leibnizian metaphysics was most often considered a delirious daydream." Locke’s prestige made it impossible to take seriously the monads as well as the preestablished harmony that Wolff, in any case, had reduced to no more than an explanation of the relationships between soul and body, which took away its general metaphysical value and made it less acceptable to common sense. However, it is no less true that the innovators whom we shall encounter were familiar with Leibniz, and that certain important themes in Leibnizian thought are to be found, more or less distorted, in their works. This is the case with the principle of continuity, very widely accepted by naturalists, who were to use it in order to maintain that there was no definitive line of demarcation between nature’s kingdoms.!* It was especially the case with the conception of matter. Without entering into the Leibnizian theory of “formal atoms, “metaphysical points,’ or “points of substance,’ ’* the new philosophers were to make use of the monad by adapting it to a corpuscularist or atomist vision of the world. It was the material atom that they would endow with force, “appetite,” and “perception.” Here, too, the Cartesian notion of a passive matter gave way to a dynamic conception of a matter whose autonomous force manifested itself as soon as external obstacles were lifted.’ Similarly, the notion of thought as something always clear and conscious was replaced by a much broader definition that had room for obscure, confused, and even insensate perceptions, for the low-level “sensitivity” granted each corpuscle, even those of inanimate bodies. Finally, the role of the organization of living beings, which allowed the confused perceptions of corpuscles

to gather together to form the animal's distinct perception, was most often to be conceived in Leibnizian fashion. In short, the new philosophy, at the very moment when it turned its back on Leibniz’s thought, felt its influence so powerfully that it might justly be called “neo-Leibnizianism.” Neo-Leibnizianism or neo-Spinozism? We are now aware of the role played by Spinoza in eighteenth-century thought.’* We must not, however, forget that Spinozism held no interest for the scientist of 1750; the philosophes were always inclined to condemn its a priori reasoning and its style, which they considered theologico-Scholastic gobbledygook. Even in the case of those who acknowledged their adherence to it, there was profound misapprehen-

sion, and the misunderstandings that enabled Diderot to fancy himself a

374 THE PHILOSOPHERS SCIENCE Spinozist are well known.’” Nonetheless, the science of 1750 may have owed Spinoza its ability to extricate itself from the dilemma that had trapped the thought of 1670 between blind chance and divine interference. It was also

very likely indebted to him for the theory of a single substance capable of comprising the two apparently irreconcilable attributes of extension and thought. On this point, Spinoza joined hands with Locke, however wide the

gulf that may in fact have separated them. But it must be added that this single substance would be identified with matter—which was not Spinoza’s idea of it—and that thinkers would endow this matter with its own dynamism. This essential idea of Spinoza’s would be perceived through a Leibnizian prism, in the kind of synthesis that the English deist John Toland had attempted in 1704 in his Letters to Serena,'® and that was appearing elsewhere independently of him.’? In this synthesis, the two philosophies so completely lost their specific characters and their basic features, and found themselves so utterly betrayed or misconstrued, that one may legitimately wonder what

more distant fountainhead poured forth the torrent that was to inundate the century, bearing along with it like flotsam the debris of the greatest seventeenth-century systems of thought. If Spinoza’s single substance became matter, if Leibniz’s monads became atoms endowed with force and perception, virtually only Epicureanism, as revived by Gassendi and popularized by Francois Bernier and his friends, could have been responsible. We have seen that at the end of the seventeenth

century, Epicureanism had triumphed on two points: skepticism with respect to human reason and the corpuscularist vision of matter. Conversely, regarding integral mechanism and the rejection of final causes, and regarding atheism and recourse to chance as an organizing factor, it had been defeated and doomed to disappear, along with Descartes, whom it had, so to speak, annexed. Driven out of science, then, it had nonetheless continued to exist, melded with the confused and powerful current of anti-Christianity. No doubt the clandestine literature attacking the Church and Revelation was above all of deist inspiration. But everywhere atheism showed its face, even

. under Spinozist guise, it was Epicurean themes that, by necessity, reappeared. Was it not Epicureanism that asserted the materiality of the soul, the natural tendency of atoms to motion, and the spontaneous appearance of forms, particularly of living forms? Was it not Epicureanism that provided the im-

| petus towards “the materialist interpretation of Spinozism” that is found in so many clandestine manuscripts?*° When Jean Meslier wrote that being — which was to say, matter—possessed parts that divided, melded, and com-

Precursors and Mavericks 375 bined “and by means of this they can constitute bodies and objects of all sorts of forms and shapes, even animals of all species,””! he was at least mighty close to Lucretius. Above and beyond the specific details of philosophic opin- —

ions, the atheism of 1720 owed its energy and its major tendencies to the Epicurean tradition of the preceding century. It would be hard to believe that the Cardinal de Polignac devoted the 12,000 Latin verses of his Anti-Lucréce to doing battle with a phantom that had already vanished.?? Moreover, the monster was still so much alive, and so far from overwhelmed that we shall

find Lucretius quoted constantly by our authors, often in company with the physician Guillaume Lamy, that “rabid Epicurean.” *° Newton, Spinoza, Leibniz, Epicurus. To this quartet one would have to add Locke, if his influence had not already been felt since the beginning of the

century and already contributed to the formation of the spirit of the preceding period. After 1745, he was an undisputed master. Finally, two glorious figures from the past made their reappearance on stage: one silently, Descartes;

the other with great acclamation, Francis Bacon. Dressed in 1750 fashion, which means more or less disguised as an Epicurean, “relieved” of his metaphysics and his vortices, Descartes became the model for those who dared to aspire to understand nature. Other paths than his would be taken, but no one dreamt of laughing any more, and the weight of his genius became cause for astonishment.”* Bacon, whose work seems mainly to have concerned philosophers in the seventeenth century, had not been forgotten at the dawn of the eighteenth century.”° Nonetheless, Voltaire, who made of him “the father of experimental philosophy,” noted in 1734 that the Novum Organum, “the most unusual and the best of his works, is the one that has today become the least read and the most useless.” Voltaire explained this by the very success of the work: science had come far enough now to do without this “scaffolding.” 2° The explanation was not very good, and the science that Voltaire was thinking of was in fact not truly faithful to the spirit of Bacon. As late as 1751, d'Alembert, placing the illustrious Chancellor among the tutelary gods of the Encyclopédie, expressed regret that his works were “more highly esteemed, however, than read.””’ Too inclined, however, to see in Bacon only the enemy of systematic thought and the apostle of empiricism, d'Alembert no doubt did not properly assess the influence he had already exerted over Buffon. More than Voltaire or d’Alembert, it was the defenders of the new science who were to rediscover the spirit of Bacon; it was Buffon, it was John Needham, who cites and copies him without identification, and it was Diderot, who would see fit to write in 1754: “I think I have taught my fel-

376 THE PHILOSOPHERS SCIENCE low citizens to esteem and read Chancellor Bacon; this profound author has

! been leafed through more often in the past five or six years than he had ever been before.” ”* It is not fortuitous that Bacon’s De interpretatione naturae should have found its strongest defender in Alexandre Deleyre, author of an Analyse de la philosophie du chancelier Francois Bacon.’? On the relationships between experience and reason, on the reality of scientific knowledge, on the uselessness of final causes, Diderot would find in Bacon a master all the more

adapted to his designs in that the two philosophers were reacting against the same spirit of religious skepticism. Newton, Locke, and Bacon taught respect for facts, and everyone loudly proclaimed that facts were the only source of truth. We know that in 1745 this was nothing new, and that where observation was concerned, the scientists of the first half of the century needed no lessons from anyone. On the other side, Leibniz, Spinoza, Descartes, and even Epicurus were master systematizers. But it appeared ever more obvious that one could not merely go on collecting data. In 1740, Mme du Chatelet condemned Descartes’s overreliance on hypotheses, but noted that “Newton and especially his disciples fell into the opposite excess,” °° and she devoted an entire chapter to the defense of sound hypotheses: “When one can feel sure of knowing the greatest number of circumstances accompanying a phenomenon, then one can seek the reason behind them through hypotheses, at the risk of course of correcting oneself and very often being corrected; but these efforts to find the truth are always cause for glory, even if they bear no fruit.” *! The following year the naturalist Gilles-Auguste Bazin, a correspondent of Réaumur'’s since 1737, turned the preface to his Observations sur les plantes into a veritable manifesto in favor of “conjectures.” “The current system, regarding physics, [is] to have no system at all, and to proceed with naught but experience in hand.” *? But our experiences could not “always follow nature without losing sight of her.” 33 Had we then to remain silent, out of respect for “the majesty of nature,” or because “silence is better in these cases than plausible reasoning, even represented merely as such?” *4 But then, the struggle among opinions abetted the progress of research and, above all, “conjectures are the mother

of experiment, it is they that engender the idea of them, that provide the means for them, and that lead to them.” *” Thus, despite the persistent confusion in vocabulary, the distinction emerged between observation and the experiment that tested the hypothesis. The Journal des Savants gave a careful resumé of “this ingenious defense of conjectures.” 3° A few months earlier, it had reviewed the work of an English physician, Dr. Bodley, who argued that

Precursors and Mavericks 377 it was not sufficient merely to be constantly involved in experiments in order to take one’s place in the ranks of such as Boyle and Malpighi. Experiment

must be conducted by the light of the superior mind. For “the experiment is always such as is the wit.” In a fool, “it will never be but an empty name under which ignorance or mediocrity will cloak themselves.” Finally, experiment had “led almost all the physicians in opposite directions”; it was merely “a source of contradictions, prejudices, or pride.” *” Brought up short by this indictment of experimentation, which disclosed, moreover, the old mistrust by doctors of empiricism, the journalist accused the author of Pyrrhonism. And this, we should note, was not completely inaccurate. One can discern in certain authors a kind of hyper-skepticism that takes on experimentation itself. “Experiments should already have decided this question, if there were ever anything conclusive in physics,” Maupertuis wrote in 1744 concerning

the existence of viviparous eggs.** “In these recent centuries, during which | people have taken a liking to experiments,’ Jacques Gautier-Dagoty would write 1n 1750, “a large number of naturalists have performed them, and not two of them have drawn the same conclusions from them.” *? It was less a matter of criticizing observation than of clarifying its role, however, limiting its importance, and blaming the abuses of those who made it an end in itself. “Let us use experiment as our walking stick,” La Mettrie liked to say, taking his cue from Mme du Chiatelet. But let us not become embroiled in a useless mass of tiny facts: They would weigh us down without increasing our understanding, and these facts in any case are found in the books of those indefatigable observers whom I make so bold as to call most often the philosophers’ handymen. Let him who so wishes take pleasure in boring us with all the wonders of nature: let one spend his life observing insects, another counting the tiny bones in the hearing membrane of certain fish, even in measuring, if you will, how fara flea can jump, not to mention so many other wretched objects of study; for myself, who am curious only about philosophy, who am sorry only not to be able to extend its horizons, active nature will always be my sole point of view; I love to see it from afar, in its breadth and its entirety, and not in specifics or in little details, which, although to some extent necessary in all the sciences, are generally the mark of little genius among those who devote themselves to them.*°

To be “curious about philosophy” meant to seek to discover the great laws of nature, through the phenomena within which shortsighted observers got lost.

“The taste for systems, better suited to flatter the imagination than to enlighten reason, is almost completely banished today from worthwhile writ-

378 THE PHILOSOPHERS SCIENCE ings,” states d'Alembert in the “Discours préliminaire” to the Encyclopédie. Yet again: “The spirit of hypothesis and conjecture may have been very useful

of yore... . But times have changed, and if a writer presented a eulogy of systems among us, he would be arriving too late.” 41 We should not be fooled by a fallacious conditional. D’Alembert was perfectly aware that a eulogy of systems had been presented before the full Académie des sciences at the inaugural public assembly of November 13, 1748, by Jean-Jacques Dortous de Mairan.*? “The terms system and chimera appear synonymous today,” Mairan had said.42 No doubt we ought not to misuse system. But “does one not misuse experiments if they are not carried out with method and enlightened by reasoning? Which virtually amounts to saying: if they are not accompanied by the spirit of system.” 44 Newton, Kepler, Harvey, and Copernicus all created

systems. “In brief, one need only glance through the history of the human mind relative to the natural sciences, to be convinced that systems have at all times been a fertile source of discoveries, or at the very least of observations

and experiments that one might not ever have thought of, had the systems not engendered the idea.” 4° Mairan was, moreover, neither an isolated figure nor even a latecomer. In 1749, Etienne Bonnot de Condillac’s Traité des systemes, which attacked metaphysical systems with such vigor, considered that the object of physicists “should be to observe phenomena, grasp their interrelationships, and work back to those upon which several others depend.” *° The ordering of known phenomena would “enlighten us concerning the experiments we still need to do; it will point them out to us, and will allow us to form conjectures that will often be confirmed by observations.’ *” It was therefore not a question of excluding conjectures; one merely had to know

how to use them. In the same year, the first three volumes of the Histoire naturelle appeared, and from the outset Buffon made it clear that the intention of his natural history was not only to “do precise descriptions,” but also “to combine observations, to generalize facts, to link them together by virtue of analogies.” This was “greater and still more worthy of occupying us.” *® Much later, Buffon was to attack even more bitterly “those writers who have no other merit than to cry out against systems, because they are incapable not only of creating any but perhaps even of understanding the true meaning of this word, which frightens or humiliates them.” * In 1754, in his De l'interprétation de la nature, Diderot was to define the three necessary stages in scientific knowledge: “observation of nature, reflection, and experiment. Observation gathers the facts; reflection combines them; experiment verifies the result of the combination.” *° To our eyes, this truth is old hat; but at the time

, Precursors and Mavericks 379 it needed affirming. Countless others would repeat it after Diderot.”’ The Encyclopédie itself would give the lie to d'Alembert: “There are two excesses to be avoided regarding hypotheses, that of holding them in too high regard, and that of banishing them entirely.” Whereupon it rehearses the arguments presented by Mme du Chiatelet, cited as an authority at the end of the article along with Condillac’s Traité des systémes.* Without taking anything away from the necessary role of factual observation, the new scientific thought intended, then, to go beyond it and to rehabilitate hypothesis and “system.” It was not a question, certainly, of reviving an outmoded past, and we shall see in what ways the new systems differed from the old ones. Nonetheless, the new science would multiply systems and the “observers” faithful to the spirit of the preceding period would find this a subject of bitter reproach: all the more bitter in that the systems would nearly all tend to place in the service of atheism a science that had devoted itself to the service of God.

I

Maupertuts We have already seen that despite his vocation as a mathematician and astronomer, Maupertuis had not thought it beneath him to study salamanders and scorpions.*’ Like the declarations of principle that accompanied them, these studies closely aligned him with Réaumur and the scientific observers. Nonetheless, he was already following other paths. In 1732, one year after his report on scorpions, he published his “Discours sur les différentes figures des astres” (the first openly Newtonian work by a Frenchman), and he entered into relations with Voltaire, whom he converted to Newton.>4 Next came the demanding friendship with Mme du Chatelet and in 1739, after a trip to Lapland, a visit by Samuel Koenig, who introduced Leibniz’s philosophy to the little group and provoked a momentary falling out between the astronomer and the marquise, which Voltaire patched up.*? The outcome of all this in Berlin is well known, especially Koenig’s role in the matter, but the intimacy that reigned in 1740 between Voltaire and Maupertuis leads one to assume deep affinities between the two men. Nonetheless, Maupertuis’s “Essai de cosmologie,” which he published only in 1750, but which had already existed at least in provisional form in 1741,°° shows he had already gone further than

Voltaire. |

380 THE PHILOSOPHERS SCIENCE The “Essai” presents itself, in fact, as the search for a satisfactory proof of the existence of God, and it is striking to see that from the opening pages, Maupertuis breaks with the thought of Newton and of all those who, following in Newton's path, sought to prove God’s existence through the order

and harmony that reign in nature.°” Indeed, for Newton, the existence of a creative intelligence is demonstrated straightaway by the fact that the six known planets “move in the same direction, and describe more or less concentric orbs” around the Sun.** Newton, Maupertuis observes, might also have noticed that the planets “all move in almost the same axis.” °? Uniformity such as this, Newton had thought, “necessarily proves a choice” and excludes “blind fate.” °° But no matter how probable this uniformity may be according to the laws of chance, it was nonetheless not impossible, and this being the case, one cannot say that this uniformity must be the necessary effect of a choice.

But there is still more: the alternative between choice or utter chance is grounded only in Newton’s incapacity to provide a physical cause for this uniformity. For other philosophers who have the planets moving in a fluid that bears them along . . . , the uniformity of the course does not seem at all inexplicable: it no longer assumes a peculiar stroke of chance, nor does it prove the existence of God, any more than any other movement impressed upon matter.®

In other words, an explanation based upon chance was not necessarily absurd—here one sees the emergence of the calculus of probabilities whose role was to be so important in later developments—and above all, Maupertuis underscored the fundamental weakness in Newton’s argument and indeed in Newtonian cosmology: it was for lack of having assumed a physical cause for

the movement of the planets that Newton was obliged to see in its uniformity the effect of chance or of divine will. Buffon’s cosmology, conceived by 1744,°* was destined precisely to fill this gap, and it is remarkable that Maupertuis should have alluded to a system of Cartesian inspiration in order to point out the inadequacy of the proof admitted by Newton.®? Still following Newton, Maupertuis moved on to the animal kingdom and had little difficulty in demonstrating that diversity was greater than uniformity there.°* “The suitability of the different parts of animals to their needs” seemed to provide a “more solid” argument, and it seemed quite unreasonable to say, along with Lucretius, “the greatest enemy of Providence,” that “chance having formed the eyes, the ears, the tongue, we then have used them to hear, to speak.” ®* With that said, did the existence of God find itself demonstrated? Absolutely not:

Precursors and Mavericks 381 Might one not say that in the chance combination of nature’s productions, since only those endowed with certain relations of suitability could survive, it is no cause for wonder that this suitability is found in all species that exist today? Chance, one might say, produced an innumerable multitude of individuals; a small number turned out to be constructed in such fashion that the parts of the animal could satisfy its needs; in another, infinitely greater number, there was neither suitability nor order: all of the latter have perished; animals without a mouth could not live, others lacking organs for reproduction could not perpetuate themselves: the only ones to have remained are those in which were found order and suitability; and these species, which we see today, are only the smallest part of what blind fate produced.®

After Buffon, it was Diderot whom Maupertuis foreshadowed in picking up once more the thought of Lucretius, which radically undermined all search for teleology in nature. Maupertuis did not, however, stay with this position, which risked leaving untouched hearts sensitive to the harmony of the world.

With something akin to fury, he emphasized the ridiculousness, the inde- | cency even, of arguments founded on animal organization. What were we to think “of him who finds God in the folds of the rhinoceros’s skin because this animal, covered as it is with a very hard skin, would not have been able to move without these folds?” °” People weighted us down with admiration at the care Providence had taken in creating the snake or the fly. “But what is the point of it? The preservation of an animal whose tooth kills man,” °* “the production of an insect bothersome to men, that the first bird to come along devours, or that falls into a spider’s web”? %? In order to find God’s intervention in all this, “cleverness of execution is not enough: the motive must be reasonable.” ”° Very often, it did not seem to be such: “Are so many poisonous plants and harmful animals, produced and carefully preserved in nature, meant to reveal to us the wisdom and goodness of Him who created them? If one found in the universe nothing but things of this sort, the universe might merely be the work of demons.””' This apparent disorder resulted no doubt from the inadequacy of our minds. But in that case, silence should be the rule. For all these debatable proofs founded on natural phenomena, which were “better suited to amaze than to enlighten our minds”? and capable of giving aid and comfort to incredulity as well as faith,’*> Maupertuis sought to substitute a proof founded on an examination of the /aws of nature, the laws of motion. Considering that motion was not a property essential to matter,”4 he nevertheless went beyond that position of the philosophers who had “placed the cause of motion in God . . . because they did not know where else to place it”:”? using the principle of the least quantity of action,’® he demonstrated “that

all the laws of motion are founded on the principle of the best,” after which

382 THE PHILOSOPHERS SCIENCE “one can no longer doubt that they owe their existence to an all-powerful and

all-wise Being.”’’ He could thus reply to charges that he had attributed to Providence an order that could result only from the nature of things: “If it is true that the laws of motion are the indispensable results of the nature of bodies, that in itself proves the perfection of the Supreme Being: for all things have been so arranged that a blind and necessary mathematics executes what the most enlightened and freest intelligence had ordained.” ”* Even if motion were essential to matter, God would still be proven by “the least quantity of action.”

When the “Essai de cosmologie” appeared in 1750, this proof was judged too obscure; it drew the reproach of “being accessible to only a small number.” ”? In point of fact, through his attacks on the partisans of final causes and proofs of God’s existence drawn from the natural sciences, Maupertuis was throwing off balance a state of mind that had already become a tradition and, at a still deeper level, had called into question the generally accepted role of God in creation. The proof by /east action was very different from the proofs founded on the perceptible wonders of nature: the God whose existence it set out to demonstrate was far closer to the God of Descartes than to God the creator of insects or even Newton’s God, who with His own hand had launched the planets through space. Indeed, this was what Voltaire would chide Maupertuis for. In appearance, it was all the same to Maupertuis whether God “acts directly” or “has given bodies the power to act upon one another.” *° But when one refused to admire the details of creation, when one saved all one’s admiration for “those laws that constitute the principle of motion of all bodies in the Universe,” and whose “application we can admire in all phenomena, in the motion of animals, in the vegetation of plants, and in the revolution of heavenly bodies”; when one asserted that “the spectacle of the universe becomes far fairer, far more worthy of its Author,” “it is then that one can have a proper idea of the power and the wisdom of the Supreme Being; and not when one judges them by way of some small part of which we know neither the construction nor the use nor the connection it has with other parts” ;** when, in sum, one wished to seek God “in the first laws He imposed upon Nature, in those universal rules according to which motion is saved, distributed, or exhausted, and not in phenomena that are merely overly complicated consequences of these laws”;** then was it not evident that one was conceiving of a God the Lawgiver rather than a God the Craftsman, and a universe in which phenomena resulted from the harmonious play of secondary causes rather than the direct action of the Creator? Here again, Maupertuis foreshadowed

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Buffon and broke with Réaumur. He clearly owed much in this regard to astronomy: his basic vision of the world rested upon the contemplation of celestial mechanics and its regular motions, subject to simple mathematical laws. When he then approached the study of living beings, he was convinced that the complexity of facts hid the simplicity of laws, and his early experience was, in this regard, exactly the opposite of that of Réaumur, who had been put off the search for causes by this very complexity. It was because he was not a naturalist that Maupertuis dared to attempt an explanation of the phenomena of reproduction. But at the same time, his thought occupied a singular crossroads, where the most diverse influences met. Still a prudent disciple of Newton,®? he was not unaware of either Leibniz or Malebranche,®4 and quite often Descartes himself put in an appearance. Neither was Lucretius far off, although his positions were not accepted without reservation. By bringing together Newton and his adversaries in this way, Maupertuis was laying the groundwork for the synthesis that the new science would attempt to achieve.

UP TO THIS POINT and despite the observations of 1727 and 1731, the living world had played only an accessory role in the thought of Maupertuis or at least in his work.®° A minor social event—the presence in Paris of an albino African child who was being exhibited in the salons — offered him the Opportunity to write two modest occasional works on reproduction destined to attract considerable attention: the Dissertation physique a loccasion du négre blanc, published in 1744, and Vénus physique, published the following year.°° However, the “white negro” was merely a pretext and the Dissertation 1s in fact a brief treatise on reproduction: only the Vénus physique deals with the problem of human races and hereditary variations.*” The critical positions adopted by Maupertuis in this work are immediately striking. Not even experimentation is immune to his skepticism.** He denounces the illusion of wishing to find in living nature a uniformity that satisfies our reason even when it is belied by the facts.*’ Thus he refuses to raise the objection to Leeuwenhoek of the excessive number of spermatic worms nor does he wish “to debate which confers more honor on nature, an exact economy ora superfluous profusion: a question that would require a better knowledge of nature’s views, or rather the views of Him who governs her.” ”° In brief, People create a satisfying system for themselves, while overlooking the characters of the phenomenon they wish to explain: as soon as they uncover them, they see the inadequacy of the reason presented, and the system evaporates. If we think we know something, it is only because we are extremely ignorant.

384 THE PHILOSOPHERS SCIENCE Our mind seems destined to reason only on things that our senses discover. Microscopes and telescopes have provided us, so to speak, with senses beyond our reach, such as might be found in the higher intelligences, [i.e., angels—‘Tr.] and that incessantly outstrip ours.??

Above all, “we do not at all understand how at each reproduction an organized body, an animal, can be formed.” ”? In all this, Maupertuis was faithful

to the spirit of his time: he was pursuing precisely the path that led to the preexistence of germs. But his skepticism did not spare even preexistence, which he criticized with visible precautions and with possibly deliberate discomposure. The existence of viviparous eggs was not demonstrated: Méry and Verheyen had performed experiments that called it into question. The observations of Harvey, which Maupertuis drew out of long oblivion, were incompatible with preexistence of any sort. If one admitted the existence of preexistent germs, it was impossible to understand the phenomena either of heredity or hybrids or monsters.”* After all these unrelated observations, the conclusion is surprising in its clarity and its almost violent tone: I therefore apologize to the modern physicists if I cannot accept the systems they have so ingeniously conceived: for I am not of the sort who believe one helps progress in physics by adhering to a system despite some phenomenon that is clearly incompatible with it; and who, having noticed some aspect that will inevitably lead to the

downfall of the edifice, nonetheless finish building it, and inhabit it with as much assurance as if it were the most solid in the world.

What was in fact new here was this conclusion. It had been known, as we have seen, that preexistence could not explain certain facts, but it was nonetheless not discarded. If Maupertuis rejected it, this was first of all because he attributed great importance to the phenomena of heredity (which had been too readily neglected before him) and to Harvey’s observations, which had been forgotten. But, perhaps above all, it was also for philosophical reasons. Moreover, the chapter that presents these reasons is very curious. Maupertuis pretends at first to consider preexistence as a purely physical system and

he has no problem in showing that the simultaneous natural formation of all living beings encased in one another is still more inconceivable than the formation of a single isolated being. Then, moving on to the level of divine creation, he shows just as easily that for God, who exists outside of time, the simultaneous or successive creation of animals is all the same.2> Thus, on the level of nature as on that of creation, preexistence offers no advantage. But in reasoning this way, Maupertuis pretends not to see that no one had conceived of preexistence as resulting from a natural and simultaneous formation of all

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germs, that the present creation of living beings by God had been set aside because it would be miraculous, and that consequently the true alternative would oppose divine simultaneous creation to natural formation occurring in the present and individually. Maupertuis’s reasoning thus seems sophisticated. But he shows himself willing radically to separate the natural from the divine, and his intention is unmistakable: he did not intend to maintain that God creates each animal in the present. It was because he wished to explain the natural and present formation of living beings that he dared to praise Descartes, his Traité de [homme (universally disparaged for three-quarters of a century), and his theory of generation.”° If he rejected preexistence, it was because far from making “physics more luminous,” ?” it made it unquestionably murkier. Similarly, he rejected ovism and animalculism, not only because they were not demonstrated clearly enough, but also because in his thought, as in that of his contemporaries, the two systems were in practice fused with the theory of preexistence. The real merit of Maupertuis in this matter lay in his having reestablished the principle of epigenesis; in other words, in having brought the problem of generation back into the domain of secondary causes and having restored to

science a question that had been abandoned to metaphysics. But the philosophical character of the undertaking was uncomfortably evidenced by the absence of any new fact, as well as by the author’s alacrity in getting rid of ovism and of animalculism. After this, it would have been prudent not to propose any system, and, indeed, Maupertuis was careful not to.?* He goes on, however, to present some “vague thoughts” and “questions for examination,” which turn out in fact to be a theory of generation based on the mixture of the two seeds, analogous to that of Descartes. He presents it with restrictions that allow us a better understanding of his intentions: It is true that in saying that the fetus is formed from the mixture of the two seeds, one

is far from having explained this formation: but the obscurity that remains should not be imputed to our manner of reasoning. He who would know too remote an object and who registers only a blurry image of it, is more successful than he who sees objects that are not the one in question more distinctly.?°

Preexistence did not resolve the problem of generation: to him who wished to study the formation of an animal, it answered by speaking of its creation; the vaguest conjectures as to the causes of epigenesis would therefore always be preferable, for, as confused as one might consider them, they still answered the question asked and not another.

Maupertuis thus returned to the mixture of the two seeds, male and

386 THE PHILOSOPHERS SCIENCE female, each of which contained the parts destined to form the embryo.’ How did these parts come together in the proper order? Traditional mechanism had not been able to answer this old question, which was why Maupertuis rejected Descartes’ explanation of procreation.” But like Descartes, he saw no difference in nature between living and inert matter. Nothing, therefore, kept him from establishing analogies between vital and chemical phenomena, the latter of which sometimes oddly imitated life.'°* Now, the chemists had to acknowledge that there were affinities among chemical bodies

that forced them to unite in the presence of one another. A body united to another would separate out in order to unite with a third with which it had greater afhnity. Here Maupertuis cited the chemist Etienne-Frangois Geoffroy and his “Table des afhnités,” and he had no qualms about saying that “these forces and these afhnities are nothing else than what other more daring philosophers call attraction,” nor about asserting that “the most famous chemists today accept attraction, and extend it farther than the astronomers have.” 1° At this point, the conclusion is easy to predict: Let us admit such properties or such affinities in nature, and we shall not abandon all hope of explaining the most difficult phenomena. Let there be in each of the seeds the parts destined to form the heart, the head, the bowels, the arms, the legs; and let each of these parts possess a greater affinity of union with the one that, for the

formation of the animal, must be its neighbor than with any other; the fetus will be formed: and were it a thousand times more complex in organization than it is, it would be formed.!4

The phenomena of heredity were readily explainable, since the embryo was formed of parts furnished by the two parents. If the corresponding parts were too remote “or too weak in affinity of union,” a monster would be born by default. Teratoid superfluity obviously resulted from an extra part, and the “relationship of union” readily explained the fact that an extra finger was always found on the hand or the foot (which Dortous de Mairan, as we have seen, could understand only in terms of the preexistence of germs). As for spermatic animalcules, whose existence was beyond debate, “perhaps they serve only to create movement in the prolific fluids; to bring together in that way parts that are too far from each other; and to facilitate the union of those parts that must join together.” 1°° We have seen that this stance with respect to the spermatozoa was not original at this date. Newtonian attraction, as understood by the chemists, offered Maupertuis a solution to the problem that traditional mechanism had not been able to resolve. It is thus all the more striking to see him pass beyond this solution in

Precursors and Mavericks 387 the final chapter of the Dissertation physique.'°’ Instead of an attraction or an “affinity” between the parts of the seed, might one not, he wonders, imagine

an “instinct” in them that would impel them to unite? No matter if this in| stinct were only an “occasional cause” of the motion of these particles, or that its wishes coincided only through a “preestablished harmony.” The “instinct” in question would resolve the problem of generation still better than attrac-

tion. It is probable that the influence of Leibniz, who had explained vital phenomena through “an entelechy,” a “vital principle endowed even with a perceptive faculty,” °* was making itself felt here, and that Maupertuis imagined the particles of seed as psychic units along the model of the monad, but attributing to matter what Leibniz had attributed to substance. What makes

this influence highly plausible is that Maupertuis immediately contradicts himself by wondering whether this “instinct,” which he has just assumed to be “dispersed among the parts of the seeds,” did not belong to “some indivisible part” that would be “the essence of the animal” and would survive its death, retaining the power to take on a new body of the same species or even of another species.’ In this still confused thought, which foreshadowed the

theory that Maupertuis was to present in his “Systeme de la nature,” it is easy to recognize Leibniz’s concept of the preexistence and the immortality of germs. We have seen that Leibniz’s influence can be traced in Maupertuis's “Essai de cosmologie,” and Koenig was without implausibility able to attribute the paternity of the principle of least action to Leibniz. From all these similarities, and from many others that could be cited, we must conclude that Leibnizian thought was at least one of the points of departure for Maupertuis’s reflections, whatever hostility the latter may have shown towards the fanatical disciples of the great philosopher."° It would be easy to emphasize the utterly hypothetical character of Maupertuis’s theory, his quickness to dispose of all the observations performed on viviparous eggs, and the unfair simplification that his mechanistic vision brought to the phenomena of generation, except when that vision vanished before the action of a somewhat incomprehensible instinct. He cannot, however, be charged with ignorance or frivolity. I have noted the extent to which the theories based upon eggs or spermatic animalcules had in themselves become fragile, in addition to being undermined by the absurdities of preexistence. Microscopic observations, which complicated the issue and made the scientist overlook more accessible data, might well have become the object of similar distrust: “Our mind,’ writes Maupertuis, “seems destined to reason only on things that our senses discover. Microscopes and telescopes have pro-

388 THE PHILOSOPHERS SCIENCE vided us, so to speak, with senses beyond our reach, such as might be found in the higher intelligences, and that incessantly outstrip ours.” ™ Rather than to the detailed analysis of an isolated datum, Maupertuis devoted himself to the interrelations among data. Part 2 of Vénus physique, dealing with the “white negro,” gathers together very specific ideas on heredity,

on the appearance and disappearance of inherited anomalies, and on the fixity and variability of species, and one senses that Maupertuis’s research into procreation originated in these reflections. Like all his contemporaries, Maupertuis believed in the fixity of species;"” but this fixity did not exclude the possibility of transmission of acquired characteristics, on the subject of which precise experiments would have to be carried out."* He saw this transmission

occurring by virtue of the fact that each part of the adult’s body provided

' the seed with elements that would eventually compose the same part in the embryo.'"* It was therefore possible that blacks owed their color to the prolonged action of the tropical sun."’” But the seminal fluid not only contained elements from the paternal or maternal body. It also, in a fashion left unexplained by Maupertuis, contained elements received from ancestors, even distant ones. If an accident activated these atavistic elements, rather than those from the parents, the child would resemble an ancestor. The existence of the “white negro” could then be explained through a reemergence of this nature, from which one might conclude “that white was the color of the first men.” 1! Maupertuis layed little stress upon this idea, however, as indeed upon the origin of blackness. What interested him was the fact that there currently existed in the hereditary legacy of each species elements of distant origin, susceptible of returning suddenly to view in individuals of abnormal appearance like the “white negro.” These variations were, of course, hereditary, but they tended to get lost through crossing with normal individuals. They could be perpetuated through “art.” Thus “we see species of dogs, pigeons, canaries, that had not existed in nature beforehand. They had at first been merely fortuitous individuals; art and repeated generations have made species of them.” '”” It is worth noting that Maupertuis seems here to be defining species only through their hereditary persistence, and that in reality what he designated by this term were varieties or breeds. In the circumstances, it seems impossible to speak of transformism in connection with the Vénus physique, all the more in that Maupertuis emphasizes the fact that the “varieties” that suddenly appear are most often resurgences of ancestral characteristics."* Still, the originality and importance of the book are not diminished thereby. Not

Precursors and Mavericks 389 only did it, as noted, return the problem of generation to the level of science, but it brought about a true shift in perspective. Abandoning the temporarily sterile field of anatomical research in favor of the study of hereditary phenomena, it reinserted the living individual into the succession of beings of its species. The two maneuvers were parallel: the search for the origins of the individual being immediately confronted the scientist with the unknowable, while the study of the data of heredity turned the living being into a phenomenon tied to other phenomena and thus a possible object of science. The consequences of this were to be immense and it is indeed true, in this sense, that transformism began with Maupertuis. Finally, despite its contradictions and obscurity, the last chapter of the Dissertation physique moved towards the overturning of biological mechanism itself. In all these senses, Maupertuis was opening the way for the new philosophers. He was the first to break with a scientific mentality already three-quarters of a century old, and he did so in a highly original manner.'”? The real timeliness of his undertaking was attested by the success of his Vénus physique.'*°

Things had changed somewhat and Maupertuis was no longer alone in 1751 when he brought out his “Systéme de la nature” in Latin under a pseudonym.’*! Needham had published his first microscopic observations, Diderot

his Lettre sur les aveugles, and, above all, Buffon the first three volumes of his Histoire naturelle. The “Systeme de la nature” proves that Maupertuis knew these works, just as their authors had known the Vénus physique. But Maupertuis’s thought maintains its own direction, and the “Systéme de la nature’ merely picks up and refines ideas with which we are already familiar. This refinement had its price, however. Maupertuis quickly rejected the system of natures plastiques’?? and criticized the preexistence of germs with far more vigor and clarity than in the Dissertation physique of 1744:'?? “To assume all individuals to have been formed through the will of the Creator in a single day of creation is to tell of a miracle rather than to give a physical explanation.” 124 And on this crucial point involving the relationship between Creation and science, Maupertuis’s thought had become extremely clear: he claimed to accept the Mosaic account without reservation and to study only the laws that preserved the already-formed world,'”’ but this “preservation”

of the world was not coterminous with the immutable persistence of created beings. Maupertuis might have believed that the world had been created formless, but he said nothing about it. He merely evoked the catastrophes that had brought chaos back to the surface of the globe. The result was the

390 THE PHILOSOPHERS SCIENCE same, since present-day nature had gradually been formed in this way, starting out from a primitive state in which everything had been blended together. Life, then, appeared spontaneously.'?° For practical purposes, Maupertuis thus readopted the position of Descartes. More specifically, he took the stance that Buffon was also to take—

that is, he did not go all the way back to Creation but to a state of nature prior to the current state, and to the most remote state that he could plausibly reconstitute. The rejection of final causes, which had already found expression in the “Essai de cosmologie,” now reached its logical conclusion: one

ought not to seek God in the details of animal forms, for these forms did not come directly from Him; they resulted from the processes of the laws of nature, and it was in the wisdom of these laws that the Supreme Intelligence was to be sought. By the same token, however, the natural forms of living beings, like other natural forms, were no longer an inexplicable given. Their appearance in the world became a possible object of science. One might seek to know according to what law of nature metals, marbles, animals, and man were formed. This last inquiry would be even easier, for living beings continued to be formed under our very eyes.'”” The generation of animals thus acquired exceptional importance, since it was destined to allow us to understand the process of nature through which all things had been formed. Starting with the opening pages of the “Systéme de la nature,” Maupertuis rejected any mechanistic explanation of generation, including the one in the 1744 Dissertation physique that had invoked attraction. In effect, it would be necessary to assume as many forms of attraction “as there are different parts in matter,” '? and doubtless Maupertuis no longer believed it possible to play in this way with universal gravitation.’? Since, then, “a uniform and blind attraction, spread out through all parts of matter can no longer serve to explain how these parts are arranged in order to form the body whose orga-

nization is the simplest . . . , we must have recourse to some principle of intelligence, something similar to what we call desire, aversion, memory.” '°° This clarified everything: “The elements suited to the formation of the fetus swim in the seeds of the father and mother animals; but each, extracted from the part similar to the one it is to form, keeps a kind of memory of its prior placement; and it will resume it again whenever it can, in order to form the same part in the fetus.” 9! The transmission of inherited characteristics and the fixity of species were

thus assured. Should an accident come about to upset the usual order, this stroke of chance brought into existence a variety of the original species, a

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variety that would normally be inheritable through the same action of habit

and memory that the seeds kept from the abnormal body that produced them.}52 Convinced, on the one hand, that animal forms resulted from the functioning of natural laws of the sort we could know, and noting, on the other, the spontaneous appearance of accidental varieties capable of perpetuating themselves, Maupertuis found himself led to the first complete formulation of generalized transformism: Might one not explain thereby how from two lone individuals the multiplication of the most dissimilar species could have resulted? They would have owed their first origin to only a few fortuitous productions, in which the elementary particles had not preserved the order they held in the father and mother animals: each degree of error would have made a new species: and through repeated deviations there would have been produced the infinite diversity of animals that we see today; which will perhaps increase still more in time, but to which perhaps the progression of ages brings only imperceptible changes.'%?

A daring philosophical stroke—and almost entirely philosophical, inasmuch as it went far beyond the scientifically established data, at a time when paleontology could be of no help. Buffon himself would not go this far.’%4 Maupertuis had reached the extreme limit of his thinking, the limit at which he utterly contradicted the scientific mentality of the first half of the eighteenth century. In the 1744 Dissertation physique, Maupertuis had moved from universal gravitation to chemical affinities and from chemistry to biology. Now, for the reason that we have seen, he followed a reverse progression. From the generation of animals, he passed to the formation of crystals, “Diana's tree” * metals, and marbles.'* The same system could be applied everywhere. Nonetheless,

Maupertuis did not overlook the difficulties engendered by according this intelligence to the slightest particles of matter, and, in order to resolve them with greater ease, he discussed them only in connection with living matter. The sensitive soul that Scholastic philosophy had granted to animals constituted a rather sound defense against the theologians.'*° For it was clear that ~ once intelligence was granted to animals, one could attribute it without further risk “to the tiniest parts of matter.”!°” But this argument from intelligence had no power against the philosophers, especially if they were Cartesians. True enough, against the latter there existed a traditional argument that had seen much use ever since Locke and Spinoza: if extension and thought *“Diana” was the name early chemistry gave to mercury, and the “tree of Diana,” or “Diana's tree,” referred to the dendritic amalgam precipitated by mercury from a solution of nitrate of silver. — Ed.

392 THE PHILOSOPHERS SCIENCE were “merely properties, they can both belong to an object whose particular essence is unknown to us” '°*—that is, matter. The data required that we accept thought in matter, just as they had required that we accept attraction in it: so much the worse for the simplicity of our philosophy, for “a philosophy that cannot explain the phenomena can never pass for simple; and one that accepts properties that experience demonstrates to be necessary is never too complex.” !°? Moreover, there were many levels of intelligence, even among men.'*° One might, then, grant elementary particles a form of intelligence as dull and as obtuse as one liked.!*! In this way, Maupertuis himself contributed to the extraordinarily important evolution leading from the Leibnizian idea of a soul added to matter to the idea of a “dull sensitivity” granted to matter itself, an idea to be encountered again in La Mettrie and Diderot. Finally, would not accepting intelligence everywhere be tantamount to afhrming the existence of a Supreme Intelligence? What system could more effectively lead to God and refute the impious delusions of Epicureanism?!4? There remained a difficulty that would appear crucial in the eyes of Diderot,!43 but that Maupertuis regarded as secondary: if each of the elements constituting an animal possessed its specific perception, how did these perceptions unite to form the psychic identity of the whole animal? This was a mystery, Maupertuis replied, accepting nonetheless that each element did possess a kind of perception appropriate to the role it was to play in the animal’s perception,'4 and hinting that the human soul itself might be nothing more than a collection of elementary perceptions.'* Maupertuis was not to return to biological problems before his death in 1759,'46 but one can easily see the exceptional importance of his intervention. The aim of his undertaking he defined himself in 1752, in the “Lettre sur le progres des sciences’: “In order to turn natural history into a true science, one would have to devote oneself to investigations capable of telling us not

| the particular shape of such and such an animal, but the general procedures

of nature in the animal’s production and preservation.” 147 He certainly did not consider himself to have completed this task. But at least he had rendered it possible by throwing off the yoke of the current mentality; by moving out from under a mode of thought in which the preexistence of germs, the contemplation of final causes, the notion of a Craftsman God, and the fixity of forms condemned the scientist to remain within the realm of pure and simple description; by giving back to nature its existence and its organizing activity under the direction of a Lawgiver God; by reestablishing the principle of epigenesis; and by restoring to man, by the

Precursors and Mavericks 393 same token, the possibility of understanding the appearance of living forms, which ceased presenting themselves as a given irreducible to analysis. Still, even as he afhrmed—first and foremost by the very existence of his work — that a science of nature was possible, he had not remained satisfied with repeating Descartes. He built up his syntheses from phenomena, as Newton had wished, and hypotheses were not certainties for him. This rejection of a priori reasoning marked the limits he established for a science that was to remain positive. Even as he restored its rights to human reason, he limited its pretensions, picking up once more the very formulations of the skepticism of his time, even if he was not a skeptic in the traditional sense of the word. Maupertuis carried out this reestablishment of reason and experience with respect to each other, or, if you will, this synthesis that marked the birth of a new rationalism, without a blaring proclamation and as if by instinct. But those who were to establish the principles of the new science— Buffon and Diderot— recognized what he had done, as the importance they assigned to his work sufficiently proves. Refusing to become absorbed in the description of forms, and wishing to discover the relationship of phenomena in order to determine their laws, Maupertuis was led to study the life of animal forms and species in the flux of time and not in the moment. It would be impossible to overemphasize the crucial influence of the reintroduction of duration, an essential dimension, into the science of life. In the area of nature in its totality, Maupertuis found himself led to an examination of the data of heredity, to the idea of the history of life, and to the affirmation of a generally operant transformism. There is no need to speak of the prodigious repercussions of what was truly a revolution in human thought. In the area of the coming into existence of being, or ontogenesis, this introduction of time corresponded to the notion of a progressive formation, an epigenesis. Of course, Maupertuis remained a prisoner of a corpuscularist vision of matter: conceiving of the formation of being as a juxtaposition of particles, he did not succeed in freeing himself from traditional mechanism, and his theory of generation remains open to criticism.

The importance of that theory lies above all in its affirmation of an elementary intelligence attributed to the particles. This afhrmation may appear gratuitous, but we must first recognize that it would be quite easy to transpose into the language of modern genetics many of the observations of the phenomena of heredity that Maupertuis formulated in psychological terms. Moreover, contemporary thought has not utterly rejected the psychological interpretation of life.!48 The repercussions of this idea, alluded to more than

394 THE PHILOSOPHERS SCIENCE once in this book, are in any case what is of the essence for our purposes. Through this aspect of his thought, as through all those aspects noted above, Maupertuis played a considerable role in the elaboration of a new science and a new vision of nature.

II La Mettrie

The physician Julien Offray de La Mettrie, a compatriot and protegé of Maupertuis’s, remains a singular figure in the history of ideas.!4? In his haphazard and often contradictory work, only two convictions are unshakable: materialism and atheism. As for the rest, his thought is more vehement than clear. However, we cannot overlook it, as much because of its originality as because of its repercussions.'°°

After studying with Boerhaave in Leiden, La Mettrie had spent ten years of his life translating the works of his master, setting forth his own medical ideas, and criticizing his colleagues when he published his Histoire naturelle de lame,'”’ the first methodical treatise on integral materialism, in 1745. The interest of the book resides in the attempt at a psychophysiological explanation of mental phenomena, but this is not what is relevant here. Rather, we need to consider the chapters in which the author explains his theory of matter. He obviously considered it to be eternal, “the enlightenment of faith” alone allowing us to believe the contrary. It possessed certain qualities, among others extension, a quality “co-essential with its subject,” but not constituting its essence, whatever Descartes might have said.’°? Here, the criticism of Cartesianism evokes Leibniz, but a materialistic Leibniz: “Mere extension does not give a complete idea of the entire essence, or metaphysical form, of the substance of bodies, by the very fact that it excludes the notion of any activity within matter.” ’°? On the contrary, one had to accept that there were in matter a motive force [/a force motrice] and a sensitive force. In particular, the notion of matter as passive, denuded of qualities, and defined only by extension had to be conceded to be an unreal abstraction. Matter was totum in feeri— “all in potency.” 14 It did not exist except as endowed with “substantial

forms,’ which made perceptible and, so to speak, “realized” the motor and sensitive faculties that were in matter in a latent and potential state.’ Up to this point, La Mettrie’s thought is impregnated with Scholasticism, and it is not too surprising to find him citing Leibniz and a seventeenth-

Precursors and Mavericks 395

century Thomist in footnotes. We are a long way from Boerhaave and physiological mechanism. But that mechanism suddenly reappears when La Mettrie moves from a general theory of matter to the study of living beings and the vegetating and feeling faculties that he, like the ancients, called souls. In living bodies, substantial forms were of two sorts: “those that constitute the organic parts of these bodies and those that are seen as being their life principle. It is to the latter that they [the ancients] gave the name of soul.” °” The vegetative soul, then, was a substantial form, but La Mettrie rejected the opinion of moderns who had “confused it with the organization of plants or animals itself, whereas it is the cause that leads and directs that organization. '** The vegetative soul had to be imagined as a material ether found in all bodies; there was much of it in fire and air, less in water, and still less in earth. The vegetative soul gathered nourishment from the ether contained in its food, as Guillaume Lamy had explained. Here La Mettrie abandoned the dynamism of Aristotle to return to Epicurus and the Gassendist conception of the igneous soul. As for the manner in which the soul “leads and directs” the organization of living bodies, he gives us a thoroughly mechanistic notion of it: It is in fact not possible to conceive of the formation of living bodies without any cause presiding over it, without a principle regulating and leading everything to a determined end; whether this principle consists in general laws through which the entire mechanism of these bodies’ actions functions, or whether it be restricted to particular laws originally residing or included in the very germ of these bodies, and through which are carried out all of its functions during their growth and duration.!”?

Should that material ether, the vegetative soul, be identified with the general or particular laws regulating the development of bodies? La Mettrie’s thought remains unclear, and the same ambiguity is found with respect to the sensitive soul: it is none too clear whether this is a “power to feel” resulting from the organization of the nervous and cerebral system or a material “sensitive being” dwelling in the brain. La Mettrie wanted to remain a mechanist. That was what kept him from quite frankly granting motion and sensitivity to matter and led him to give an incoherent definition of substantial forms. On one point, however, he was obliged to admit that there was “in the motions of animate bodies something other than an intelligible mechanism.” He was attempting here to explain the instinct of animals, and to this end we find him invoking Maupertuis and accepting “a certain force that belongs to the smallest parts of which the animal is formed,” thanks to which all animals “seek out necessarily what is suited to the preservation of their being and have a natural aversion that reliably guarantees them from what could

396 THE PHILOSOPHERS SCIENCE harm them.” ?!©° For La Mettrie, this amounted to admitting the inadequacy of mechanism on this particular point.

L'Homme-machine, published in Leiden at the end of 1747,'*! is much clearer. The overall intention of the book was to show man to be no more than an animal—that is, no more than a machine, but La Mettrie again found himself impelled to bring up his theory of life. He unequivocally condemned “the ancient and unintelligible doctrine of substantial forms.” \ For this empty metaphysics, he could now substitute an indisputable fact: muscular irritability. A muscle taken from a body contracted when stimulated; a frog’s heart continued to beat for more than an hour; a piece of polyp reconstituted an entire polyp.'°? Therefore, “each little fiber or part of organized bodies is moved by a principle that is its own.” This principle resided “in what the ancients called the parenchyma—that is, in the very substance of the parts.” 164 Each fiber possessed a “natural oscillation” that persisted for a while after death. This was what Claude Perrault and Thomas Willis had awkwardly named a “remnant of soul.” “In fact, what is this remnant of soul, if not the

motor force of the Leibnizians, badly rendered by such a term, but nonetheless indeed glimpsed by Perrault in particular?” It was therefore “clearly demonstrated . . . that matter is moved by itself, not just when it is organized, as ina complete heart for example, but even when this organization is destroyed.” 1° We still could not know “how matter, from inert and simple, becomes active and composed of organs.” But this was of little concern if _ the fact was demonstrated by experience. From this solid point of departure, La Mettrie could resume his materialistic and mechanistic interpretation of mental phenomena. He could also—and this is of more particular interest to us here—set forth his determinist, atheist vision of the world. He refuted at length the deism of the “physician Diderot’s” Pensées philosophiques, “a sublime work that will not convince an atheist.” '°° Demonstrating the existence of God through the wonders of nature was merely “verbiage better suited to

strengthen than to undermine the foundations of atheism.” !°” | We really do not know nature: causes hidden in her bosom may have produced everything. Take your own look at Trembley’s polyp: does it not contain in itself the causes that give rise to its regeneration? . . . [Are there not] causes the absolute invincible ignorance of which sends us running to a God who is not even a reasonable being, according to some? To destroy chance in this way does not amount to proving the existence of a Supreme Being, since there may be something else that would be neither chance nor God; what I mean is nature, the study of which consequently can only create unbelievers; as is proven by the mode of thinking of all its most successful examiners.!68

Precursors and Mavericks 397 Thus, nature—which was to say the rigorous functioning of natural laws — took the place of God and became the only conceivable “anti-chance.” It was this “active nature,” which La Mettrie loved to “see from afar, in its breadth

as in its generality,” 1°? that constituted the subject of the little work entitled L’Homme plante, published in Potsdam and Berlin in 1748. “We are beginning to get a glimpse of [its] uniformity.” We should not go too far, however, for nature “often fails to follow its own favorite laws.” !”° We could show a great number of analogies between man and plants, not only in their anatomical structures, but also in their ways of reacting to climate. One could act upon men as on plants, through selection.'”! The differences were no less great for that, but the unity of nature was profound, and ultimately one arrived at the vision of an “imperceptibly graduated ladder, through all the steps of which nature passes with exactitude, without ever skipping, so to speak, a single

rung in all of its diverse productions.”'’? From plant to man, there was a progression in the faculties of movement and feeling, which each being possessed precisely according to its needs:'”* “The more needs an organized body has, the more means nature has given it to satisfy them.” The formulation remained teleological: La Mettrie could surely not have affirmed that the need had created the organ. How life had appeared and how it was transmitted still needed to be explained. A few indications scattered through the works mentioned already

show that La Mettrie was an animalculist or, more specifically, an ovovermist!”4 and a supporter of epigenesis, the process of which he described.'” We also know that he did not accept Maupertuis’s theory.'”° The spermatic

worm was really “an insect that puts down its roots in the matrix, like the fertilized germ of plants in theirs.” ’”” Man came from the worm as the butterfly came from the caterpillar.'”® All this got repeated in 1750 in the Systeme d Epicure, in which La Mettrie set forth a panspermist theory: plants and insects were born from germs coming from the air;’”” likewise the germs of men

had first been prepared by the air, and had then undergone a lengthy elaboration in the spermatic vessels and the testicles. Finally, they developed in the egg.'8° But this rather bold system was not of crucial importance in the eyes of its author. What were important were his conjectures on the origin of life as he set them forth in the same Systéme d’Epicure, having provided a sketch of them earlier the same year in his Réflexions philosophiques sur lorigine des animaux. Admittedly, these conjectures were somewhat flimsy: the first seeds of men came out of the air and were received by the earth.'*’ These initial generations were imperfect, as was proved by the monstrosities that still appeared

398 THE PHILOSOPHERS SCIENCE in our time.'®? “Through what an infinite number of combinations matter has had to pass before arriving at the lone combination that might produce a perfect animal!” 18 Nonviable beings had automatically disappeared, and nature had learned little by little, so to speak, to make a man. Perhaps we would have to accept an idea from Benoit de Maillet, author of Telliamed, ou Entretiens d'un philosophe indien avec un missionnatre francais . . . , whose system was “more or less identical to that of Lucretius,” and believe that the human egg had been left by the sea in its retreat and hatched in the sun.'** At least it was certain that the newborn human might have found nourishment from plants or the milk of animals that might have adopted it, examples of which were known. For one human pair to have survived was in any case sufficient.’®? It is clear that in all this La Mettrie was content to follow Lucretius. And in vigorously laying out the basis for his thinking, he followed him too. First, he reiterated his rejection of final causes, which were belied by the disorder of nature. “It seems to me, given the extreme state of disorder that things are

| in, that there is a sort of impiety in not assigning everything to the blindness of nature.” 18° Second, he affirmed his determinism: “Once certain physical

laws had been established, everything that is had to be.”'*” Third, he refused to have recourse to an ordering intelligence in order to explain nature's successes: “The elements of matter having managed, by moving around and blending with one another, to create eyes, it was as impossible not to see as not to see oneself in a mirror.” '** If the eye respected the laws of optics and the ear those of acoustics, it was because of the laws of motion that had regulated their formation.'®? Similarly, nature “having made without seeing eyes that see, it has made without thinking a machine that thinks.” ’?° All this was certain, far more certain than conjectures on the origin of life. Although his psychophysiological theory of the human mind was solidly grounded in scientific data, La Mettrie’s thinking thus remained much more conjectural in matters pertaining to nature, the origin of life, and the transmission thereof. Not that he was ignorant of his contemporaries’ work: he

cited Maupertuis, Diderot, Needham, Buffon, and de Maillet.’?' He also knew his predecessors. But he followed his own path. He was never able to abandon the mechanism that Boerhaave had taught him in his youth. A great _ admirer of Descartes,!°” and well acquainted with the ideas of Leibniz, whom

he wished, so to speak, to turn upside down’? and whose dynamism had remained alien to him, La Mettrie stayed faithful above all to Lucretius, Epicurus, and Guillaume Lamy.!** His Histoire naturelle de lame foreshadowed Condillac, but the Systeme d’Epicure arrived too late and made no contribu-

Precursors and Mavericks 399 tion. The true merit of La Mettrie’s work, from our point of view, is, first of all, that he underscored the importance of muscular irritability, albeit with-

out extracting from it all the profit he might have; it is also that he made evident the underlying tendencies of the new scientific philosophy: rejection of final causes and a God/Creator, and a belief in determinism and in the unity of nature. Even in this, however, La Mettrie remained more oriented towards the past—that is, towards Lucretius —than towards the future.'””

I] Needham

To take the measure of both the unity and the diversity of the new philosophy, we need only pass from La Mettrie to John Turberville Needham, whose first microscopic reports appeared in London in 1745 and were translated into French in 1747. Needham tends to be known only by way of a mistaken observation that resulted in the disinterring of spontaneous generation, and because of Voltaire’s amiable epithets for him, “the eel fellow” and “the Irish Jesuit.” His name is most frequently connected with that of Buffon, and his work is obscured by the latter’s Histoire naturelle. Needham was, however, a scientist who constructed a metaphysics based upon his microscopical observations, and by reason of that fact alone, he would deserve our attention. In addition, however, he was one of the most original and perhaps even — despite his obscurity —one of the most powerful thinkers of his time.

NEEDHAM WAS BORN in London on September Io, 1713.’°° Through his father, he belonged to the junior and Catholic branch of the Needham family of Monmouthshire, whose head bore the title of Lord Kilmorey. Thus he was in no way Irish. Starting in October 1722, he attended the English School of Douai.!?” Ordained a priest in Cambrai on May 31, 1738, he was a professor of rhetoric and then headmaster of the Catholic school in Twyford, near Winchester. At no time does he seem to have had any relationship with the Society of Jesus.'°8 Towards 1744, he was named professor of philosophy at the English School of Lisbon, where he remained for fifteen months. It was there that he made his first important observations with a microscope, which he published upon his return to London in 1745 as An Account of Some Microscopical Discoveries.’°? Most of the book was devoted to study of the squid. Needham had become interested in this creature because he was convinced

400 THE PHILOSOPHERS SCIENCE of the unity of nature, because he thought there existed analogies among like beings of different sizes, and because he hoped to find analogies of this sort between the squid—a kind of polyp—and Trembley’s polyp, whose mysterious capacity for regeneration might thus be elucidated.*°° But the squid was to lead him far indeed from the polyp. In examining squid milt, Needham discovered mobile little bodies resembling tiny pumps, composed of a cylindrical body inside of which was a tiny barrel depressed by a spring, and furnished with two valves.?” Immersed in the seminal fluid, these tiny pumps filled up. Separated from the squid’s body, they relaxed upon contact with water, expelling the fluid they contained, which turned out to be composed of little opaque globules swimming in a serous liquid.”°* These pumps

were therefore true machines, and the agent of generation had to be this globulous matter that they sucked in and then expelled. Did one not, then, have to assume that the spermatic animalcules were in reality prodigiously tiny machines rather than living creatures?*°> Needham gave special emphasis to this hypothesis ?°* because a series of observations on floral stamen dust

had shown him that the particles of this dust, when moistened with water, exuded globules very much like those in the seminal fluid of the squid.’°’ Finally, before ending his book with observations of lesser import, Needham set forth a theory destined to create a stir: upon examining the black powder found on a grain of wheat spoiled by corn-cockle under a microscope, he had noticed bunches of fibers, which he then moistened with water. He had been

“much surprised to see them, as it were, instantly take Life, move regularly, not with a progressive, but twisting Motion at each End, and continue so to do till the next morning.” *°° Without giving a moment's thought to spontaneous generation, he assumed that these “eels” or “aquatic animalcules” had to be responsible for the pathology in the grain. The only problem was in understanding how these animals could come back to life upon contact with water, given that some of those he had examined had remained dried out for two years.7°”

Returning to London, Needham continued his investigations. It was then, at the end of 1745, that he began, along with his friend James Sherwood, to observe the “eels” found in a sourdough made from wheat flour. The first discovery, communicated immediately to the Royal Society,?°* was that these creatures were viviparous. “Consequently,” added Sherwood, “I cannot favor the common Opinion among Naturalists that all kinds of Animalcules are produc’d by minute Eggs floating in the Air.”*°? Where did the “eels” come from then? To find out, Sherwood had prepared fresh dough, which he set in

Precursors and Mavericks 401 jars, some of which were covered with a fine tissue or a bladder and the others left uncovered. In this way one might discover whether the animalcules came from the air or from the dough. Unfortunately, Sherwood’s letter reporting on them in Philosophical Transactions did not give the results of the experiment. It should be noted, however, that although the idea that microscopic creatures came from airborne germs was generally accepted at that time, Needham harbored doubts about this origin as early as the end of 1745. A little later, he performed observations along with his friend John Hill on a broth of vegetable seeds, in which he discovered tiny moving bodies that appeared to be mobile but inanimate beings. Did the spermatozoa belong to this particular class? ?!° Towards the middle of 1746,7" while the reports published in 1745 were

drawing some protests,”'* Needham left London for Paris. He did not arrive there unknown. Abraham Trembley, who had been in England from June to November 1745 in the role of tutor to the young son of the count of Bentinck,?!? had made his acquaintance even before the publication of An Account of Some Microscopical Discoveries.* Not only had he taken the trouble to have the book translated into French,?!> but he had also written to Réaumur to make sure the translation would be distributed in France.?!° Needham thus found himself in an ongoing relationship with Réaumur.?’” : At the same time, however, he had got in touch with Buffon, to whom he had been recommended by Martin Folkes, the president of the Royal Society. Buffon may himself have had the idea of having An Account translated into French.*** Whatever the case, Needham regularly saw Buffon, who was at that time passionately interested in Louis-Guillaume Le Monnier’s research into electricity, and in his own research into focusing mirrors.”!° This discovery by the Paris scientific world certainly distracted Needham from his microscopical observations. Nonetheless, he was elected a member of the Royal Society on January 22, 1747, the first Catholic priest to be admitted into the group.

| It was not easy, however, to be simultaneously a friend of Réaumur’s and of Buffon’s, and Buffon was more likely than Réaumur to have attracted Needham. They shared a taste for philosophical reflection, or, better, for theory, and both were concerned with problems raised by the generation of animals. Buffon had already elaborated his hypothesis of organic molecules, which he set forth to Needham,??° whose observations he felt confirmed it, for both scientists urgently wished to destroy the myth of preexistent germs. More specifically, Buffon expected Needham to help him in demonstrating that spermatic animalcules were not animals but rather “tiny machines” like the “seminal vessels” of the squid, and that they played no role in repro-

402 THE PHILOSOPHERS SCIENCE duction. Needham was at that point quite ready to believe it, judging that “Motion in general was but an equivocal Argument, and did not necessarily imply Life in the common Acceptation of that Term.” ?*? Convinced of the existence of a “scale extending throughout nature,” he judged that there had to be an intermediate stage between the living and the inert, and that this stage was represented by the moving bodies he had been able to observe in the broths of vegetable seeds prepared by Hill??? Buffon and Needham decided to collaborate. “Thus,” Needham writes, “did our Enquiry commence upon Seed Infusions, from a desire Mr. de Buffon had to find out the organical Parts, and I, if possible, to discover which among these moving Bodies were strictly to be look’d upon as Animals, and which to be accounted mere machines.” **? Begun on March 16, 1748,?74 these collaborative observations

must have ended by May, for it was on May 18 that Buffon deposited at the Secretariat of the Académie des sciences a sealed envelope containing a resumé of his investigations into generation. Then he left for Montbard, as he did every year. The collaboration of the two scientists had thus lasted only

, two months. Left alone in Paris, Needham continued to work. In the month of July, his observations were finished, and he had drawn his major conclusions when he received from London a brochure from Cadwallader Colden, who, by different paths, had arrived at notions quite close to his.”?° Finally, on November 23, he sent Martin Folkes a long letter giving an account of his observations and of the conclusions he had drawn from them.??°

THIS REPORT began with an exposition of principles: we must “advance no Proposition rashly; nothing, but what seems to flow naturally from observation, but this “will not exclude now-and-then a probable Consequence from appearing.” *?” The great danger was to misuse reasoning by analogy.” This was what has led naturalists to imagine the theory of preexistent germs, whose weaknesses and impossibilities Needham displays with great precision.’”” All the difficulties are reviewed: heredity, hybrids, teratisms, reproduction of plants through cuttings, and partial regeneration among animals, even without taking into account the special absurdities of the theories of encasement and panspermia, and without, as well, taking into account the philosophical difficulties and the gratuitousness of hypothesizing an absolute fixity of natural forms. The theory of plastic natures was no doubt in better conformity with the facts, but it was philosophically of dubious acceptability: one might as well attribute “the Regularity and Motion of the Planets to the Ministry of Angels.” ?°° Nonetheless, the only acceptable explanation of ob-

Precursors and Mavericks 403 served fact was undoubtedly an epigenesis directed by “constant forces” that God had established in nature. “Thus we may reduce Nature to what it is really ever found to be, simple in the Beginning of its Course, but magnificent beyond Expression when distributed.” 7°? The formulation comes close to echoing Buffon; at least it demonstrates Needham’s intention to restore nature to its rightful place.

Let us move on to the experiments. The first dealt with an infusion of almond pieces preserved in a bottle carefully stoppered with a cork. After a week, particles in motion were found in it. This motion did not come from a fermentation of the liquid but “from an Effort of something teeming as it | were within the particle.” “Atoms” were detaching themselves from the mass of seed and were advancing with a progressive movement. But “the Motion

was not spontaneous; for these Atoms avoided no Obstacle, nor had any other Characteristic of Spontaneity.” 7% It is clear that with the word spontaneity, Needham was designating the autonomy of the living being that reacted in an inventive fashion to an external stimulus. From this experiment, and from a great number of others similar to it performed by Needham alone or with Buffon, the two observers ended by establishing “a Distinction between animated and mere organiz’d Bodies.” 7° They conjectured that the spermatic animalcules belonged to this latter category, and that they were “produc’d in their respective Fluids, by a Coalition of active Principles,” ?*4 different in this from true animals, even microscopic ones, that were born of parents like themselves. In all of this, Needham was simply developing and clarifying his earlier ideas. Nevertheless, he could not manage to be entirely convinced of the spontaneous appearance of “mechanical bodies.” He was then “[d]etermin’d to convince myself and others, without any Possibility of Doubt, whether these moving Atoms were really produced from without, or from the very Substance infus’d.” *°? He then devised the first experiment performed on the spontaneous generation of microscopic beings: he poured into a vial some fluid drippings from roast meat, added a little boiling water to it, closed up the vial with a cork stopper that he sealed in order to obtain hermetic isolation, and set it “in hot Ashes . . . (so) that if anything existed, even in the little Portion of the Air which filled up the Neck, it might be destroy’d, and lose its productive Faculty.” 7° In brief, everything had been sterilized with heat. Now, in four days, the vial was filled with microscopic animalcules, “Multitudes perfectly form’d, animated, and spontaneous in all their Motions.” 23” Therefore, it had to be admitted that these animalcules were

being born from the dead matter in which they were found, and also that

404 THE PHILOSOPHERS SCIENCE the distinction between “mechanical bodies” and “animate bodies” had no foundation: the beings spontaneously born were all true animalcules. More

, than sixty analogous experiments, performed on different animal and vegetable substances and under different conditions, furnished the same results. With that, Needham had to abandon Buffon’s ideas. Observations performed together on spermatozoa convinced the two naturalists that the sper-

matic animalcules were born from the seminal fluid, and that in order to see them coming into existence, one needed only to observe that fluid early enough. But for Buffon, spermatozoa were agglomerations of organic molecules; for Needham, they were true animalcules, born of a vegetative force that dwelled “in all Substances animal or vegetable.” ?** A final series of experiments, begun just before Buffon’s departure and pursued thereafter, once more confirmed the existence of this force in Needham’s eyes. After ten to twenty days, an infusion of ground grain yielded a gelatinous mass, in which one could under a microscope observe the presence of filaments that were “perfect Zoophytes teeming with Life, and Self-moving,” sometimes forming bushes in the manner of coral “and other Sea Plants.” 23° From all this Need-

ham finally drew his conclusions: “It seems plain therefore, that there is a vegetative Force in every microscopical Point of Matter, and every visible Filament of which the whole animal and vegetable Texture consists.” 74° Animal and vegetable seeds were created in an “exalted” matter, which is to say a matter rich in this vegetative force. That was why in decomposing, they gave birth to microscopic animalcules, which decomposed in their turn, for every living substance tended to “advance as fast as it can in its Resolution to return by a slow Descent to one common Principle, the Source of all, a kind of universal Semen. 741 This universal seed was furnished to animals by their alimentation. It was diversified in their organs in such a way as to be able to produce only a being of the same species. Finally, to avoid any mistake concerning his

thought, Needham clarified that this “productive Force in Nature . . . goes no further than the mechanical and material parts of man.” The soul came from “the Fountain of Life, the true source of all spiritual substances.” 74? But at the same time, he was anxious to show that the existence of the vegetative

force took nothing away from God’s prerogatives, even in the order of material phenomena. Still, his thought was perhaps less reassuring on this point: I see the Whole indeed, but confusedly; yet I do see the Source of a Variety; which, boundless as it were, if permitted to expatiate at full Liberty, is nevertheless invariably confin’d, by Him who made and rules the Universe, to a certain determinate Number of Species. Time, Action, Season, Quantity of Force, Quantity of Resis-

Precursors and Mavericks 405 tance, fixing Principles, Affluence of assimilated Matter, Direction, and numberless other Variations, are all employ’d for His Purposes, and modell’d by that Almighty Power, which forms and directs the Whole.243

Properly guided by the Creator, nature thus found itself endowed with a spontaneity that might seem dangerous to many minds. Thanks to this exaltation of matter, did it not possess the power to bring entire species of animals back into existence if some extraordinary accident happened to wipe them out? 244

To avoid all possible misunderstanding, Needham, who had asked one of his French friends, Dr. Louis-Anne Lavirotte, to translate the book, decided to clarify his thinking right away. Nouvelles observations microscopiques, published in 1750, included a great number of new notes, and the last ten pages of the English text were replaced by more than 250 pages of supplementary explanations. Put together in haste, disorganized, and full of repetitions, these explanations are often obscure and the author, apologizing, calls upon the public not to back away from a second reading,”*° all the more necessary in that this time the argument would plumb the depths of metaphysics. Microscopical observation had suggested to Needham the idea of an “exaltation” of matter brought into action by a “vegetative force.” But Needham did not stop with the idea of a matter conceived in the classical fashion, animated by its own force. On the contrary, following Leibniz, whose name 1s mentioned only in passing, but whose inspiration is palpable everywhere, he worked hard to destroy the notion of a matter that was extensive, impenetrable, and divisible to infinity. Infinite divisibility and impenetrability were contradictory. In this “infinite multitude of multitudes,” this “immense number without unity,” and this “combination of combinations without source or beginning,” one could not “assign for me a single point where I might establish this universal impenetrability.” 24° To proclaim the identity of matter, extension, and solidity was to bring into existence “all the difficulties that have always been raised as objections, either by the materialists on the one hand or by the immaterialists on the other.” 74” If, along with Descartes, one had “the essence of matter consist in extension, then space and body become one and same thing, the Universe, poor in its abundance, languishes, and all of Nature loses its activity in an infnite, universal plenum.” ?4* The door was opened to the “metaphysical enthusiasm” of Malebranche and Berkeley, “matter is deprived of all physical property, pure space regains its primitive empire, and all of Nature becomes intellectual.” 24°

406 THE PHILOSOPHERS SCIENCE In order not to fall into these errors, it was necessary “to separate the notion of extension from that of solidity,” ?°° to remember that “impenetrability is an effect in Nature, and a notion stimulated in us as a result of and not prior to” experience,” and that in a more general sense “the qualities that we call primary are, like the secondary, merely relative effects, the evaluative model of which is found only in the sensations,” which led one to think that “matter, as we are led to conceive of it, is no more than a mere phenomenon, a complex result and a concurrence of several different effects.” *?” Moreover, metaphysical analysis led to the same conclusion: I submit, then, that if matter is essentially a composite, as we in fact know it is, the only way we can express ourselves intelligibly and in conformity with truth, is to reduce matter to simple principles: these principles are not part of matter, because they are not themselves composite, nor do they have extension or divisibility, because they have no parts; they are substances in which essence, existence, and action end up as the final reason, and consequently they are absolutely individual. They combine in order to form physical composites, which by their combined forces produce sense impressions; . . . extension, impenetrability, cohesion, etc... . , are consequent ideas and physical impressions produced by the system that we call our body, and are as a consequence relative to the quantity and the quality of the external action that begets them, as well as to the forces of the system that receives them. Every physical composite is therefore a combination of simple agents.?°?

This definition resulted: “Matter is a composite in which a number of simple agents combine. . . . It is from this that our notion of corporality de-

rives ... and it is the result of this combination that we call matter... . Matter is extension, because it is a combination of parts, and the agents... are not, because they are simple.” ?%4

What, ultimately, were these “simple agents” without extension whose combination constituted what we call matter? They were two antithetical principles, those of motion and of resistance. “All effects produced in the Universe are merely the result of action and reaction.”**’ “Every sensible point [i.e., every point accessible to our senses] in Nature is essentially active and reactive... , the life of the Universe is a counterbalanced action, ?°*° an action in conflict with a reaction. For the principle of resistance was not a principle

of passivity or inertia. It had “an activity as real and as positive as that of movement itself, although of a contrary nature and productive of opposite effects.” ?°” In this way, the universe and matter itself were simply the result of struggle and combination involving opposing forces, or, in other words, two energies of contrary signs. Nonetheless, the real nature of these primitive agents escaped us entirely.

Precursors and Mavericks 407 “Our knowledge comes exclusively from sensations, they result from different effects wrought upon these physical combinations we call our body.” *”* Our souls knew nothing except by comparison and grasped only relationships among things; they thus created for themselves their personal universes,

in which the ideas of things were with respect to one another in like relationships to those held by the things themselves in the external world.” “In forms of knowledge engendered only through comparisons, each idea of which is relative, all is comparison, all is relative, nothing is absolute.” 7°° That much suffices, however, in order for us to grasp the existence of opposite external agents, which authorized us to affirm the existence of the two simple

and antithetical agents.?*' But we knew them only to the extent that they opposed each other: “We cannot conceive of the resisting agent as resisting without the motor agent, nor the motor agent, as motor, without the resisting.” 7°? Moreover, the agents could not produce effects except insofar as they encountered and opposed each other.?® If there existed only a motor agent, matter would be scattered “without any relationship in an immense sphere.”

Conversely, if subject to the resistant agent alone, it “would be packed into a dense mass, and perhaps even concentrated into a single point.” *°* Could one still even speak of matter?

Thus, all beings in nature were formed through a combination of the two principles, brought together in a certain proportion particular to each being that defined it in relation to others. There was a scale of beings, along which the proportion between the two forces varied imperceptibly and con- _ tinuously. Gold and mercury were at the bottom of the scale “because they contain, in the same dimensions, the greatest quantity of resisting agents.” *°° They contained, however, “a certain proportion of motor activity,” like all bodies, even the most inert.26° At the other extreme were found the volatile forms of matter, fire, the electrical element, and finally ether, which was “a perfectly elastic milieu.” 7°” The chemical affinities and even attraction were explained by the proximity or distance of bodies in the scale of beings.”°* The scale of living beings brought us back to our point of departure—

that is, the “graduated scale of exaltation” of living matter.® For the decomposition of organic matter observed under the microscope allowed us to seize the passage from one degree to another on this scale. Decomposition was, in fact, merely a victory by the principle of action over the principle of resistance. Therefore, it produced more and more active, but less and less organized and more and more mechanical, beings. The first beings that appeared in the course of decomposition were animated by a “spontaneous”

408 THE PHILOSOPHERS SCIENCE movement, namely, one that was in some way directed and conscious. The last were “pure natural machines,” animated merely with an extremely rapid “oscillatory movement.”*”° If we now reversed our course from the most simple to the most organized, we saw that the more complex the organization became, the more the force of resistance tended to overcome the force of movement, the power of vegetation, and, so to speak, the vitality.’”! In the organized being, “the resistant force moulds, tempers, and directs, but still limits, the expansive force.” *”* And the total power not only decreased proportionately in the scale of beings as the organization became more complex, in a given individual it also decreased from the moment when the embryo began to form up until death, the exact and precise equilibrium between “vegetation” and resistance having been attained in the adult state.?”° This evolution derived from the organism’s absorption of “salts and other fixative principles that endlessly leach out from food and are deposited in the vessels.” ?”4 For observation proved that salts, especially nitrous salts, slowed

down and could stop decomposition (i.e., the freeing of the vegetating activity).?”° After death, “heat and humidity, sources of decomposition, drive off this excess of resistance.” ?”° Thus, the manifestations of life depended upon

the chemical constitution of living matter. Life itself, at least in its elementary aspects, was merely a form of the confrontation of forces that animated the material universe. If one could follow the decomposition of an organic matter beyond the last “natural machines” that the microscope allowed us to perceive, one would no doubt see that “all these gradations end up with ether.” ?’” The scale of living beings was bracketed within the general scale of beings, between gold and ether; or rather, “there is a perfect scale in Nature, which comprises every natural combination whatever if may be.” ?”° As one might surmise, in this scale of beings, plants and animals were not separated by any difference in their nature. “Substances are converted one into the other reciprocally through a very simple change, which is perhaps hardly more than a different combination.”?’? Plants became flesh in the animals

that ate them. Decomposition and the chemical analysis of the substances furnished the same results and revealed the same constituent elements.78° No

doubt “the lowest point of vegetable vitality is certainly extremely far from the highest period of animal vitality but they must be seen as continually approaching each other in an imperceptible gradation.” **' There was no frontier among beings: “Natura non fecit saltus.”

Matter was thus endlessly circulating and going up or down the scale of beings accordingly as the circumstances favored the active principle or the

Precursors and Mavericks 409 resistant principle. “Each part in Nature is in continual fluctuation, moving downward through composition or rising up through decomposition. The most exalted combinations descend while the least exalted are continually rising up. *°? The universal phenomenon of assimilation provoked incessant modifications: the most exalted substances assimilated those less so: fire assimilated wood, acid assimilated metal, the spark assimilated the powder;*? nutritive matter was assimilated by the vegetable or the animal.?84 But the residues of assimilation were less exalted than the substance assimilated, and in the living being, in which assimilation occurred by steps, these residues increased the resistant force at a rate faster than the increase of the active and vital force.?*° While a part of the matter, carried to its highest point of exaltation, was becoming capable of receiving sense impressions and “of communicating them distinctly to the attentive soul,” *8° salts were being deposited in the vessels and are slowly leading man towards death. The conditions that in digestion fostered the process of vitalization could be found elsewhere than in the animal. The decomposition of organic matter was the most current example. The active agents in this matter, “abetted by the vibrations from external heat, and solicited by the action of suitable fluids, free themselves from the weight of resistance that they had previously borne.” **? According to the degree of exaltation thus attained by the vegetating matter, “an organized body of some sort will be formed, more or less perfect, more or less complex according to the circumstances.” 788 Many animals could be formed in this way whose mode of generation was unknown to us: threadworms, tapeworms, mushrooms, and so forth.”®? If it was true “that the | seed is just an exalted portion of organized, decomposed substances, it is... reasonable to believe that Nature finds seed and matrices everywhere.” ??° If life was nothing other than a certain degree of exaltation of matter or a certain relationship between the principles of action and resistance, it was sufficient that this relationship be established for life to appear. And could one conceive of life in any other way when one saw completely desiccated grains return to life “through the assistance of heat and water,” ?' when one saw all those living beings— worms, eels [i.e., the microscopic “eels” he found in infusions of wheat— Ed.], polyps, starfish—that could be divided and whose pieces became so many “vital combinations” ???* These were phenomena that could not be explained by assuming “the most exquisite organization in an inactive substance without any other principle, or without any other property than extension and divisibility.” 7°? Life was strength and potency; it was not linked to a certain configuration of parts.

4IO THE PHILOSOPHERS SCIENCE This did not mean that they were born haphazardly. In certain conditions of heat and humidity, a matter possessing a certain degree of exaltation could give birth to only one species of being rather than another. Each seed, in the broad sense of the term, was specific, and Needham twice stressed the fact that his system rigorously excluded “equivocal generations.” ?°* Life could come into existence “in no other circumstances than those that the Author of Nature has established by invariant laws” *”? and every seed “assumes a Universe created in a perfect order.” °° At no moment did any particle of matter find itself “abandoned to chance,”??’ to that “blind chance” to which some “raise Altars,” but that was “nought but a phantom, resembling the Romans’ Fortuna, who exists only in the head of those who thought her up.” 7?* Even with the help of time’s infinity, chance could not bring into being an orderly universe, whatever the “anonymous Author of the Lettre sur les aveugles {[Diderot] may say.” °? This chance, “to which we accord a being and an empire in proportion to our ignorance even though it does not cause the fall of a leaf,” did not exist in nature, for in nature, everything was “determined from the outset. °°°

There remained a difficulty, however, concerning this birth of living beings through the decomposition of organic matter. Among these beings, some were “pure natural machines” animated with a mere “oscillatory movement.’ 3” But others clearly possessed “spontaneous” movement that presup- _ posed a “feeling and intelligent agent,” distinct from mere vitality. We should not allow ourselves to be deceived by the links we perceived between this agent and simple vitality: In physical generations, vitality, sensation, and thought succeed each other in regular fashion, and appear to follow the same order as an immediate consequence of simple organization; the reason for this is evident—no agent, be it sentient or intelligent, can, within the present system of Providence, exercise any faculty except in a manner dependent upon the material combination to which it is linked.3°

Sensation and awareness did not, however, result from life, any more than life itself resulted from organization. Just as there were a motor principle and a resistant principle, there was a feeling and knowing [sensitif et intelligent]

principle, which was also “a simple, indivisible agent, and of a nature far higher than mere motor activity.” 3° But of this agent, we are told only that it intervened at a certain level in the scale of beings, where its presence was necessary and preordained: If the combination is so complete as to require the presence and cooperation of a feeling or knowing agent, the same scale of simple activity established by God, from

Precursors and Mavericks 41 which we draw the first principles of this vital combination—the motor and resistant agent—contains and presents the feeling and knowing agent, as if naturally linked to the motor, everywhere that the Laws established by the Creator require this natural union.3%4

It was precisely this issue, touched upon only lightly here, that would propel Needham’s thought in further directions. Finally, there remained the problem—at this point easy to resolve—of ordinary reproduction. For all generation occurred in the same fashion.*°’ Needham, following Buffon, rejected ovism,°°° and we know that to him spermatozoa were creatures born from the decomposition of the seed. The preexistence of the germ explained nothing, since life did not consist of a particular disposition of material parts.°°” Recourse to God or to other plastic natures always assumes a purely passive and inert nature. It was, on the contrary, in energy and the incessant movement of nature that one had to seek the cause of the progressive formation of beings. Needham obviously believed in epigenesis, but he did not conceive of it in the fashion of Maupertuis as a gathering together of particles attracted towards one another by elective affinities. These “permanent, primeval, unalterable analogies between particles and particles are not only contrary to observation ... , but they also have all the disadvantages of preexistent germs and unalterable lineaments.” *°* Nothing is at rest in this world, even for an instant, and a particle cannot wait until its analogue present itself; it is itself, as well as the entire mass in decomposition, in a state of vicissitude, and if it does not find any analogous parts among the first ones detached, the longer it remains unemployed, the longer it will veer away from the supposed analogy that it is assumed to have with those that succeed it.>°?

In fact, what Needham was rejecting was still atomistic mechanism, founded on a geometrical conception of matter, even when this matter was animated by a force analogous to Newtonian attraction. No doubt one might compare the formation of a living being to the fabrication of a brocaded silk cloth on Jacques de Vaucanson’s machine. But this was merely a lame comparison, and nature went infinitely further than machines constructed by man,*!° for in natural machines, “the organs themselves are alive in each part.” 11 Only a completely dynamic vision of nature would enable us to understand generation. The seed, maintained in a state of equilibrium as long as it was contained in the seminal vessels, began to vegetate as soon as it left them.*'? This was the “first point of action,” “a vital spark that gradually wins out over the surrounding nourishment.” “The parts proceed one from another and are formed suc-

4I2 THE PHILOSOPHERS SCIENCE cessively.” And “as the parts of the body increase in number, the system of action becomes ever more complex” *’’ and its effect more specialized, since the organization served to “distribute and diversify, as much as possible, the effect and forces [of the] simple agents.” 3!4 This entire development was regu-

lated from the start by a precise degree of exaltation of the seed, by “those constant pulsations of action and intimate reaction” whose rhythm and amplitude were specific to each being, that each being passed on to its offspring, and that, from the first instant of embryonic life, were to rule with exact precision over all the phases of formation and growth.*! There was neither material preexistence nor material preformation but rigorous predetermination of the powers of formation. In this way, species were preserved always, to the extent that external circumstances did not interfere. For Needham admitted, on the one hand, that the individual in development might “take on certain accidental variations by accommodating itself to external causes,” *!° and that, on the other hand, “the seed of the male and the female” was not only “deter-

mined in each individual as a result of its nature and constitution” but also as a result “of its nourishment, the climate, and other obvious conditions.” 7!” This was to be expected, since “the entire organized body assists in some like way to the formation of the fetus,” ** participating in its entirety in the specific “pulsation” that defined it and that, in a universe where all was action and reaction, could not remain insensitive to the influences of the milieu.

THE WEALTH of ideas and originality of this book, requiring analysis at such great length here, are apparent. It ran too clearly counter to the thought of the time, and on too many essential points, to be properly understood. And it was not. While it attracted considerable attention, interest was mainly« focused on its microscopical observations, which everyone discussed or interpreted in his own fashion. Moreover, Needham’s thought was almost always

confused with that of Buffon, and Needham himself did nothing to dispel the misapprehension. His own philosophy was singled out only as a subject | of reproach for its “fearsome metaphysics.” 31° It would seem that Needham at first cared little about that. Starting in 1751, he was traveling about, acting as tutor to young English noblemen, and these travels deflected him somewhat from biology towards geology. In 1765, he was in Geneva accompanied by the young Charles Dillon when Voltaire published his first Questions sur les miracles. Needham had the fond idea of answering.**° He was abundantly insulted for his pains, being called “the pitiful eel fellow” and “the Irish Jesuit,”

among other less ingenious epithets. He took it all philosophically. But it

Precursors and Mavericks 413

may have been Voltaire who taught him at that time the use that the atheist philosophes were making of his microscopical discoveries.>?! Be that as it may, when he had left his duties with Charles Dillon at the end of 1767, he retired to the English seminary in Paris and got back to work. What he had in mind was to defend his work on the scientific level against the criticisms of the abbé Lazzaro Spallanzani, and on the philosophical level against those who accused him of, or congratulated him for, having provided arguments in favor of atheism. The results appeared in 1769, in the form of notes on Spallanzani’s critical observations.???

The details of the debate over the facts themselves need not be gone into here.??? Needham stressed the necessity of distinguishing between “vitality” and “spontaneity” in their interpretation: “By spontaneity I always understand a habit of life directed by the forms of knowledge that start out from a sensitive principle, superior to matter and acting with sensation towards

a particular end. The lack of spontaneity does not exclude, to my mind, a : true internal organic principle of movement, purely material, which I call vitality.” 374

This vitality, which resembled the vegetative soul of the ancients,>”> mani-

fested itself in the “active principle of irritability” recently discovered by Albrecht von Haller, a principle that was not “a foreign, passing, and accidental principle, but a true internal principle, and essential to organized bodies,” and that differed entirely from the principle of sensation, “since he [Haller]

has found organic parts that are irritable without feeling, others sensitive without irritability, and still others that are irritable and at the same time sensitive. °*° This vitality allowed us to understand how polyps, earthworms, and starfish “come apart and multiply through division.” For “the vital, which

is material and composite, divides naturally, and repairs itself through the vegetative force,’ whereas “the sensitive, which is essentially simple, cannot be divided.” °”” In fact, sensation was simple, and “one will never conceive of the division of a truly sensitive being without falling into materialism, which certain demi-philosophers have very improperly accused us of.” 3”8 The vital force also explained the phenomena of regeneration that Spallanzani himself had just discovered; regeneration of the heads or tails of earthworms or of aquatic worms, of the tadpole’s tail, of the legs or jaws of salamanders, of frogs’ and toads’ legs, and, finally and most remarkable of all, the regeneration of the heads of slugs.°”? This force, which “acts while we are asleep, independently of either our reason or our feeling,” 9° which functioned alone during violent passions, habitual acts, and fits of somnambulism,>*! thus certainly

414 THE PHILOSOPHERS SCIENCE existed. It mattered little whether one called it “organic molecules, vegetative principle, elastic force, or expansive spirit,’ *°? and, since observation presented

them to us, we had to admit that there existed beings in which this vitality acted alone, beings that were pure vital machines, and that formed “a certain class of life above pure vegetation, and below true animality.” 9°? Such were the creatures in infusions, which were “vital beings” and not animalcules: Needham had never claimed that “the vegetable changes into animal,” for there was required “in order to complete the true animal, which must be sensitive, a principle of sensation, a soul that is not composite like the organic system, but that remained “higher than vitality, and beyond all the powers of the most exalted matter.” 334 It was not a question of granting every-

thing to vitality; but we had to allow what belonged to it and particularly the formation of living beings through an epigenesis regulated by the laws of Creation. The theory of preexistent germs, “not very philosophical, and inconceivable,’ °° raised too many difficulties, which Needham recalled once again, stressing heredity and teratisms, some of which were “so constituted”

that one would have “to place them at the doorstep of the Divinity... , which seems ridiculous to me, not to mention blasphemous, and which gives the materialists far more to work with than our theory.” 3°° The existence of God was not compromised by epigenesis, quite the contrary: Despite the false views of the materialists, who corrupt the truth and give an absurd twist to our principles, what does it matter, in order to assure the Divinity its empire over this material world, and in order to exclude the supposed effects of chance ..., whether the germs of organic bodies have existed since the beginning of the world, formed directly by its Creator, or the general laws by which the universe is governed are set up in such a way according to the good and wise pleasure of God that a certain, specific effect must necessarily be produced by a certain predetermined cause? The debate, as far as morality is concerned, turns upon a simple word, namely, whether God must act directly in order to exert His sovereign empire over the cause or over its effect, with the sole difference that those who can extend their view as far as the general causes themselves to grasp the principles of nature are certainly stronger philosophers than those who have the Divinity act specifically for each effect; it was in this latter way that our forebears used the ministry of the angels in order to have the heavenly bodies turn.39”

In all this, Needham was clarifying his views, extending his proofs, and developing his ideas, but he was not adding anything really new. At the very most, one may observe that this time he was openly invoking the authority of Leibniz.378 On the other hand, the Nouvelles recherches .. . sur la nature et la religion and, more specifically, the “Lettre 4 M. de Buffon” that serves

Precursors and Mavericks 415 as a preface to it, were to go much further.**? Needham’s object in the Nouvelles recherches was to reconcile religion with physics and, more particularly, to show that an interpretation of Genesis more attentive to the spirit than to the letter allowed for a history of the Earth in conformity with experiential data and with the demands of reason. A mind like his could envisage only a progressive formation of the universe, and geology led him to deploy through time the action of the antithetical principles of action and resistance. “There was evening and there was morning: the first day [Factus est ves-

pere et mane dies unus],” says Genesis, and these words were the point of departure for Needham’s reflections. They struck him as odd, since “the evening is said to precede the morning of the first day” and this before the existence of the sun and of light itself.34° On the latter point, Needham deemed, along with Saint Augustine, “that the period of six days must be taken in the mystical sense.” 34! Still, the evening had preceded the morning, and shadow

had preceded light, which for Needham meant that the negative had preceded the positive, which was the great developmental law of the universe. “All in the universe is action and reaction, which can exist only between positive and negative beings.” 4? Perfect balance would be “total stagnation.” But “not only are brute matter and exalted matter negative and positive with respect to each other, without which there would be neither action or reaction, but also on the scale of exaltation of matter, the diverse parts are negative and positive with respect to one another.” “Electrical power” was distinguished by positive and negative. The scale of colors was such that “the graduated quan-

tities of light become for one another shadow and light.” “In the end, the sensitive agent [is] vital and the intelligent principle [is] sensitive in this reciprocity of mutual relationship, or this causality of positive and negative.” 34

Thus, at the bottom of the scale of beings, “the darkness of created things preceded the light, chaos existed before development; evening, adumbratio, preceded morning, and the negative existed before the positive,’ for it was God who “calls things that are not as well as things that are out of the state of nonexistence or privation, into that of existence.” 344 Then the scale of beings “rises gradually from the imperfect to the perfect, from simple regular apposition to vital economy and organic intus-sception; and from simple vitality to the most complete organization, passing through each class of life distinctly, with an addition, towards the middle of the progression, of a sensitive principle, until the scale ends with man, into whom, said the sacred writer, God breathed from on high a spiritual and immortal soul.” 3

416 THE PHILOSOPHERS SCIENCE This vision of the world was not, however, just metaphysical; it was historical as well, and this was perhaps the essential point: This general and particular scale . . . requires a succession in time proportionate to its internal movement, while it is becoming graduated and developed; a quantity of movement is a quantity and measure of time. In order, therefore, that it be perfectly graduated in a proper harmony to become a perfect scale, a constant alternation of rising and falling parts must be present, more or less perfectly, and the parts are positive and negative relative to each other.346 ;

What Needham found here was thus “the order of creation” just as much as the “present system of nature.” From nonexistence, God had brought nature up to man and each intermediate stage — the resistant being, the active being, vitality, the sensitive principle—was positive with respect to the preceding stage and negative with respect to the following. Each of the days in Genesis corresponded to one of these stages: Indeed, what can better sketch out for us and help us to conceive a mutual causality in a harmonic scale, composed of alternately positive and negative relations, arising at the beginning from nothingness through the infinite power of God, than an unknown and inhabitual day that precedes the sun and the natural day, according to Saint Augustine’s expression? What can better express it than a temporal cycle, rising in efficacity

by degrees, like the natural day, from negation or darkness to its Zenith, and then moving downward until it ends in negation, in order to give way to a new degree of efficacity or a new cycle, which must also become exhausted and end in the obscurity and the rest of night? The repetition of each periodic cycle of the scale ascending in perfection gives the sum total of six periods, of a length proportionate to the nature of things that become more and more exalted, just as philosophy teaches us. In order to show, then, not only that everything comes from God (which is essential to religion), but also that the start of the first cycle was linked with the terms that preceded it—by which I mean with the rest of absolute obscurity, or nonexistence, and the universal

| negation of all sensible form that preceded the direct creation of matter—not only is this cycle, the first of all, presented to us as having its night, or evening, but this evening, or night, precedes and anticipates the eduction of light itself: et factus est, etc 347

In these few pages, Needham had developed what might almost be called a dialectical vision of nature and of its history. No doubt this history was conducted by God, who seemed to have interfered in it on several occasions, especially at the appearance of the sensitive principle and the intelligent principle, which should therefore not necessarily be linked to the previous stages of Creation. But Needham, careful not to provide a handle for materialist interpretations, was perhaps unable to express his thought freely on this crucial point. It is important to note the insistence with which he speaks of the “causality of positive and negative” that united the successive stages of nature. We

, Precursors and Mavericks 417 have seen that the first stage itself was linked to the negative term that preceded it, to nonexistence. The logic of his thought and of his faith required that “each new degree of efficacity derive from God himself.” 348 But we know

that Needham preferred to believe that God acted by establishing causes rather than by creating effects directly. It was not beyond question that for him divine intervention was entirely contained in the initial fiat, from which nature would then unfold the necessary consequences.3#? Man’s spiritual soul was no doubt the object of a particular creation, but not the sensitive principle, not even perhaps the intelligent principle: they were nowhere excluded from the linkings of the “causality of positive and negative”; moreover, their immaterial nature, duly clarified, did not justify setting them apart in a philosophy in which matter was but an illusion of our senses or, at least, was merely our manner of feeling and conceiving the combinations and countervalencies of the principles of action and resistance, which were themselves immaterial as well. These linkings of causality were, however, purely metaphysical; their action was exerted only in the development of nature, and it was absurd to say that in the present state of things, matter could think. This, nonetheless, was what Paul d’Holbach claimed to prove using Needham’s experiments in his Systéme de la nature, published in 1770. By this time, Needham had left Paris, where the Académie des sciences had given him the title of correspondent on March 26, 1768. In February 1769, he had become a member of the recently formed Société littéraire in Brussels, of which he was the first director. It was therefore from Belgium that he undertook to refute d’Holbach and to protest at the way in which the Systeme de la nature had used his work. The notes that he added for this purpose to the abbé Monestier’s La Vraie Philosophie, published in 1774, tirelessly reiterate the necessary distinctions between vital beings and animals, between exalted matter and the sensitive principle.*°° These were distinctions that d’Holbach could not fail to reject. At least Needham was never to know of the exclamation in the Réve de d'Alembert: “Old Voltaire can make all the fun he wants; the eel fellow is nonetheless right.” The publication of Diderot’s dialogues was still in the distant future when Needham died a saintly death in Brussels on December 30, 1781.

One certainly cannot deny Needham’s thought the merit of originality.

No doubt he owes much to several philosophers. He knew and named Ralph Cudworth and Nehemiah Grew, Malebranche and Berkeley, and of course Descartes. His clerical background had acquainted him with Scholastic thought and Aristotle, to whom he no more than alluded, and Saint Au-

418 THE PHILOSOPHERS SCIENCE gustine, whom he used in his own fashion. He cited Bacon at length?! and adopted both Locke’s sensationalism and Newton’s attraction. Finally, and above all, he owed to Leibniz the idea of the scale of beings, his conception of matter formed of simple substances, and the notion of the two principles of action and resistance. Needham never sought to deny these influences,?*” and he proclaimed his adherence to Leibnizian metaphysics. But he always denied that his was a philosophical system: “I formed it directly upon observation, with no particular view in mind,” he affrmed.?*? And he had the right to say this. The only a priori idea he may possibly have had was that of the graduated scale of nature, so current among naturalists. But the whole of Needham’s thought rested upon a profound intuition born from contemplation of the microscopic world, which ultimately came down to the feeling that life was present everywhere. It was because he had seen the gelatinous mass of his infusions come to life under his very eyes that he was obliged to reject the idea of inert matter and a mechanistic universe, in order to replace it with the vision of a universe of forces, in which matter and its forms were merely results, or rather appearances. This was, properly speaking, a vitalist vision of the world, for physical phenomena were conceived of in the image of vital phenomena. The single motive force in nature was that graduated exaltation, that progressive activity with which matter is endowed, the principle of all physical and chemical metamorphoses, and that vegetates in plants; that composes and vitalizes organized bodies; that receives stimuli in their members; | that constitutes their idiosyncrasies; that gives birth to the different microscopic phenomena we have spoken of; that enlivens animal and vegetable seed; that diversifies all secretions; that establishes the number of species through hidden analogies; that is exalted in viviparous animals and poisonous snakes; that spreads out in contagious particles; that, by acting upon the soul through sense impressions, stimulates it to think and provides it with matter for thought; that separates the elements from one another in a scale that is precisely graduated and varied at each step; that subtilizes into electrical vapor; that shines in light under the form of seven prime colors with a thousand different shadings; that changes into ethereal matter; that makes the planets gravitate towards the sun; that unites them in a single system, and that animates the whole universe.>4

It was on the basis of this fundamental intuition, born of the spectacle of phenomena, to which he always refers back, that Needham’s thought was built. If he adopted Leibnizian metaphysics, it was because it was the only system capable of accommodating this deep vitalism, while not only eschewing materialism but even ending up on the other side of material appearances with an integrally dynamic conception of nature. No doubt it was to Leibniz,

Precursors and Mavericks 419

and secondarily to Newton, that Needham owed his theory of the two opposing principles. It then sufficed that he be led by his geological preoccupations to describe the origin of things for Creation itself to appear to him as an epigenesis directed by God and deployed in time like the successive emergence of the antithetical levels that constituted the scale of beings. And this led to the very confines of a dialectical vision of history and nature. Through this highly individual process, Needham condemned himself to

isolation and incomprehension, in an age whose contradictions he in fact claimed to transcend. A fervent Christian, a convinced Catholic, but by nature a free and tolerant spirit,*°? he aspired to reconcile religion with philosophy. He asked that Christians first of all try to understand philosophers before condemning them: “It is perhaps difficult to determine,” he wrote, “whether religion has suffered more through the ignorance of the faithless philosopher or through the absurd notions of the unphilosophical theologian.” 3° Above all, however, he asked them not to make Christianity subject to Cartesianism. He wished to “demonstrate that a philosopher, gui nullius in verba jurat [who swears on nobody’s word], can be a Christian even if he is not a Cartesian” °°’ — that is, even though he accepted neither innate ideas, nor mechanism, nor passive matter. Of the materialists, he asked that they go beyond matter and chance. Materialism and Cartesian Christianity seemed to him two symmetrical errors, both resting upon a false conception of matter. Freed from the Cartesian bias, Christianity would be able to do without

preexistent germs and direct interventions by God, get rid of the problem of teratisms, and, in short, rediscover nature and its activity without God's losing anything in the process. Materialism, in turn, would find an explanation less absurd than chance for the order of the world, without fearing that nature might vanish before God. However, in denouncing the errors of the mechanism spawned by Descartes, Needham could not manage to free himself from the constraints of his time. In order to defend himself against the imputation of materialism, he had, despite the logic of his system, to insist upon the irreducible character of the “sensible principle”; on the distance separating “vital beings” from true animals. Nothing in his thought truly required this distinction, which wrecked its coherence, and his predicament is evident. Moreover, this precaution did not succeed in justifying him. For everyone, whether Christians, deists, or materialists, he remained the “eel fellow,” the one who had claimed to make, or who really did make, eels out of dough and thought out of mat-

ter. Needham had been able neither to complete his system nor make it

420 THE PHILOSOPHERS SCIENCE. understood to his age. The double failure is worth noting: it in many respects marks the limits of eighteenth-century thought, limits that it could not overcome and that, to a certain degree, define it.

IV Benoit de Matllet

Tradition and chronology call for a brief look here at Benoit de Maaillet, whose famous Telliamed, printed for the first time in 1748,°°* is regarded as one of the works that contributed to the dissemination of the idea of transformism.*?*? Nonetheless, the author could not be taken for an adherent of the new philosophy. Born in 1659, deceased in 1738, he was a contemporary of Fontenelle’s rather than of Maupertuis’s or Buffon’s. He had conceived “the first project of his system” in Egypt, where he had been consul general from 1692 to 1708.3 He had worked thirty years on it and died without seeing it published. The book’s basic inspiration was already fifty years old when it appeared.**!

The first issue broached is a theory of the earth, in which it is demonstrated that all the continents were at one time under water. Without being truly original, Telliamed is not lacking in interest in this regard. But to the four dialogues dealing with geology, de Maillet, encouraged by Fontenelle,> added two others. The first set forth the changes that all the heavenly bodies, Earth included, went through and that led them by turns from the state of opaque globes to that of blazing suns, condemned afterwards to be extinguished, then to blaze again, and so forth to infinity. The second was devoted

to the problems of life, and in particular to the way in which it could reappear on a heavenly body that had just been ravaged by fire. This body, reduced to ashes and rendered extremely light, was impelled by the solar light

to the outer edge of the vortex, where this same solar light drove the dust and the particles of water that it was continually removing from the opaque bodies. In this humid milieu, the cadaver of the extinguished sun was soon covered with water and kinds of clay, which, adding to its weight, made it descend once again toward the center of the vortex. With the increase in heat, the water began to evaporate towards other globes.*° If the earth had been through these adventures, if it had been entirely covered with water, we had to believe that life had first appeared in the sea,>°4 and that the terrestrial and aerial species that we knew were descended from marine species.

Precursors and Mavericks 421 It is this passage from the aquatic to the aerial milieu that constitutes Benoit de Maillet’s entire contribution to the birth of transformism. The passage was “far more natural than one would commonly imagine” for air and water were “in reality one and the same thing” and easily melded with each other where there was contact (i.e., “directly above the waters).” °° As for the proofs of this origin of terrestrial and aerial beings, they were drawn from the analogies that existed between them and forms of marine life. The idea was rich in possibilities, but it is all too clear that de Maillet had no idea of a “coherent compositional outline.” He limited himself to saying and repeating that “not only the form and color are the same, but also the inclination.” *°° Colors, in particular, drew his eye: there were fish as brightly colored as parrots, and whose colors were arranged in the same fashion.**’ In any case, it was only between birds and fish that de Maillet was able to discover exact analogies and to set forth in detail the passage from sea to air in a text that, although well known, deserves to be quoted. It might happen, the author tells us, that flying fish carried away by the force of their flight or left behind by the sea found themselves stranded on the shore. At that point, their fins, being no longer bathed by the waters of the sea, split in two and drooped downwards because of the dryness. While they were finding among the reeds and grasses into which they had fallen foods for their sustenance, the outer tubes of their fins, separated from each other, lengthened and became covered with beards; or, in more exact terms, the membranes that previously had held them glued to one another underwent a transformation. The beard created out of these drooping membranes itself lengthened; the skin of the animals became gradually covered with a down of the same color it was endowed with, and this down grew. The little rudders that they had on their underside, and that, like their fins, had enabled them to move in the sea, became feet, and allowed them to walk on the earth. Still other little changes occurred in their shape. The beaks and necks of some lengthened; those of others shortened: it was the same with the rest of the body. Nonetheless, the conformity with the initial shape remains on the whole; and it is and always will be easy to recognize.>°8

With quadrupeds, de Maillet had less luck. There were sea-monkeys, sea-

/ elephants, and sea-bears. “The lion, the horse, the ox, the pig, the wolf, the camel, the cat, the dog, the goat, the sheep, also have their counterparts in the sea.” °°? Each terrestrial species, therefore, derived from the analogous marine species, and that alone would suffice to prove that transformism had absolutely nothing to do with the case here. Each marine species adapted individually to a new milieu and was modified only to the extent that this adaptation required it.

| 422 THE PHILOSOPHERS SCIENCE Since there existed a terrestrial man, there must also be a sea-man. De Maillet saw no problem with that and was even obviously pleased by the idea, bolstering it with an impressive number of proofs and attestations. To be sure, he did pass up the musician Triton spoken of by Pliny, even though that great naturalist, “who has perhaps unfairly been labeled with the name of liar,” °”° seemed quite trustworthy to de Maillet. But there were enough “attested facts, close to us in time, and available to our research.” >”! The list began with “a sea-man followed by his female” that surfaced in the Nile on March 18, 1592, and displayed themselves “for about two hours” to an “ofhcer of one the cities in the Delta.” °”* The story probably came from Ulisse Aldrovandi, who even provided a portrait of “these two monsters.” °”* Then followed a swarm of more modern facts, drawn from travelers, certified by ship captains, Jesuit fathers, or notaries, and one of which at least proved that at the end of the seventeenth century, an Eskimo was at great risk of pass_ ing for a sea-man in the eyes of English sailors: was it not evident that “from the waist down, his body was all covered with scales”?>”* To round out these stories replete with tritons and sirens and to show that the passage from sea to land was not irreversible, de Maillet related the adventure of a Dutch cabin

boy who had fallen overboard at age eight, to be fished back out of the water more than twenty years later. “He was covered with scales and had hands similar to the fins on a fish,” but he had preserved the use of his native lan-

, guage and even his liking for tobacco. Unfortunately, he soon dove back into his new element, and the written testimony of the matter, provided immediately by the captain, could not be found in the archives of the admiralty in Amsterdam where it had been deposited.°” These stories would have slight interest if they served only to demonstrate the credulity of our author. But they led him to assert that there were different species of men.3”° There were nearly speechless wild men, “forest men” or “Ourans-outans,” men with tails, beardless men, and probably one-footed men, just as there are races of giants and dwarfs. Without going so far as to endorse them personally, de Maillet quoted in an appendix some extracts from Pliny’s Natural History devoted to the Arimasps, who had only one eye in the middle of their foreheads, the Hermaphrodites, the Cynocephali, the Satyrs, the Struttopods, the inhabitants of the upper reaches of the Ganges who had no mouths and lived only on airborne scents, and the Sciapods, who had only one foot, but so wide that in the summer they lay down and used it as a parasol. To which had to be added the dwarfs of the island of Aruchetto

Precursors and Mavericks 423 who, according to Magellan’s companion Francesco-Antonio Pigafetta, had ears of such sort that they used one as a mattress and the other as a blanket.*’’ All of these species were of a kind, reproduced, and maintained their characteristics in perfectly constant fashion.?”* The climate had no influence on them.3”? De Maillet was so far from being a transformist that he did not even entertain the thought that blacks and whites might be of the same species, nor consequently that they might have descended one from the other.?*° A fortiori, “Can men with tails be the sons of those who have none?” 38! And finally the ultimate question: were all these different peoples, “in your opinion, descended from Noah?” **? Let us conclude, then, that human peoples were born and are still being born from sea-men. They were born from them without speech, like brutes, and they had remained for so long in the wild state that they retained no memory of their origin and imagined that they had been born from the earth, before coming to believe that they had descended from Heaven by a golden chain or, what amounted to the same thing, that they had been directly formed by God.?*? Sea-men were daily being transformed into earth-men. In order to catch the phenomenon in progress, one would have to go to the polar regions, into climes where the humidity and the fog fostered the transition between water and air. Moreover, one would have to hide carefully in order not to frighten these new men upon their emergence from the sea. Lacking direct observation, the barbarous state of the northern peoples was sufficient proof that their “transmigration” was still of very recent date.3*4 In any case, was not human skin covered with microscopic scales,’* and did not baths have a beneficial action upon men’s health? **° Still, if all terrestrial and aerial beings came from sea beings, where did these sea beings in turn come from? From seeds scattered throughout all the universe, in the air and in interplanetary space, de Maillet replied. Everything was filled with these seeds—air, water, foods. New seeds arrived from other planets, and unknown species were suddenly seen to appear. Normal generation was carried out thanks to these seeds, which came to rest in the adult males of their species and inside them become spermatic animalcules.**’ And where did these seeds originate? De Maillet admitted that they might be created, but it is evident that, for him, they had existed from all eternity.** This is the ultimate proof of the radical fixism of his thinking, which many have wanted to consider in some obscure way transformist. If the seeds were eternal, however, it was because matter was too. The

“theory of a beginning of matter and motion in time is repugnant to rea-

424 THE PHILOSOPHERS SCIENCE son. **? The Bible itself, if properly interpreted, assumed “the preexistence | of matter.” 9°° Here we touch upon the fundamental ideas of Telliamed and perhaps upon its deeper intentions, which at least in the last two dialogues are more philosophical than properly scientific. If the thought of Benoit de Maillet on the origin of beings and on eternal seeds linked up with or rather foreshadowed that of La Mettrie, it was because both took their inspiration from Lucretius and Epicureanism. Telliamed is a work directed against Christianity, and it is easy to understand why before being published, it circulated clandestinely in manuscript for ten years.>?! The eternity of matter destroyed the idea of a creation. The ever-renewed cycle of astronomical vicissitudes, which first set fire to the celestial globes and then darkened them by sending them alternately from the center to the periphery of the vortices, stripped all privilege from the Earth, now subject to universal law. The marine origin of man, the animal barbarity of the first tribes, and the diversity of human species were so many arguments against the Christian idea of a man created in the image of God in order to enjoy the benefits of a universe organized on his behalf. This is precisely the spirit of Fontenelle, and it is not surprising that the latter, who is often quoted and praised in 7elliamed, should have approved its design and encouraged the writing of it. Still, the intellectual exuberance of Benoit de Maillet, the intemperance of his imagination, and above all the form of his skepticism with regard to man, which impelled him to gather together the most incredible stories without regard for critical method when they served to display the ridiculous or bizarre forms that the human biped could adopt, his curiosity about the extraordinary, and his taste for peculiar scholarship, carry us further back than Fontenelle, all the way to the freethinkers of the first half of the seventeenth century. De Maillet, who cited Charles Sorel on many occasions, who furnished in his appendix an extract from La Mothe Le Vayer, and who dedicated his work to Cyrano de Bergerac, was first and foremost an unbeliever in the style of 1650, or, more precisely, one of the 1680 freethinkers who were still faithful to their masters of the preceding generations and who had not been affected by the parameters of the new science. Equally unaware of Newton, Leibniz, Spinoza, and Locke, de Maillet must have been an utter anachronism in 1748, and in fact he scarcely fits into the preoccupations of the biological mentality of that time. But the paradoxical success of Telliamed underscores the deep unity that, through the clandestine Epicureans of the first half of the eighteenth century, linked the philosophers of 1750 with the freethinkers of the preceding century. Knowledge had evolved, the parame-

Precursors and Mavericks 425 ters of science had become clearer, certain aspects of thought could even be

radically opposed to each other, at least in appearance —but it was the same | impulse, the same tradition of intellectual freedom, and, ultimately, perhaps still the same refusal to sacrifice nature, her abundance, and her fecundity, to the impoverishing diagrams of a creationism that flattered human vanity.

! NINE

Buffon

THE PUBLICATION toward the end of 1749 of the first three volumes of Georges-Louis Leclerc de Buffon’s Histoire naturelle may be considered one

of the important events in the intellectual history of the eighteenth century, and the prodigious success of the work is easy to explain, as are the violent criticisms directed against it. Never was a book more timely. The public had been fully prepared to become engrossed in its subject matter, and it discovered a writer where it had expected merely to encounter a scientist. Above all, however, the new scientific philosophy, still in search of its paths and principles, found in the new work the clear and reasoned expression of its ideal and even the fulfillment of some of its hopes. Buffon’s prefatory “Discours de la maniére d’étudier et de traiter histoire naturelle” was a latter-day Discours de la méthode and to grasp the full importance of these first three volumes and understand their repercussions in the intellectual world, one must remember

that they did not merely present still-debatable explanations of particularly controversial points of natural history at the time, but offered in addition a new conception of science—that is, a new, systematically thought-out, and conscious conception of the relationships between man and nature. My intention here is not to pursue Buffon in all aspects of his thought — after all, I should by rights be limiting myself to his theory of generation. But as with the other scientists I have dealt with so far, that theory acquires meaning only as part of a whole whose main lines must be delineated. If we neglected the way in which Buffon conceived of the rights and duties of the scientist, and of the place of man in nature, his theory of procreation would

, be no more than an insignificant historical curiosity. Likewise, we shall have

Buffon 427 to follow the evolution of the central ideas discernible in the three volumes of 1749.

I

Human Knowledge and Man’ Place in the Universe

Although not yet famous, Buffon’s name was not unknown to scientists, and perhaps even to the broader public, in 1749. Brought into the Académie des sciences in 1733 as adjoint-mécanicien |adjunct-mechanicist],’ he already had a reputation as a “good geometrician.”* He was, in fact, much involved in mathematics, especially the calculus of probabilities, and in 1740 he published a translation of one of Newton’s mathematical works.*? But he was also involved in botany, performing experiments on the resistance of wood and, along with Henri-Louis Duhamel du Montceau, on the formation of _ ligneous layers. In 1735, he had translated the English physiologist Stephen Hales’s Vegetable Staticks (1727),4 adding a preface to it in which he eulogized

experimentation, the only means of bringing about progress in science and the only guide of the “great men,’ among whom he cited Newton, Bacon, Boyle, Stahl, Huygens, Réaumur, and Boerhaave.’ It is worth noting, however, that in translating Hales’s text, Buffon made an effort to attenuate the expressions of enthusiastic admiration that the author felt in contemplation of the harmony of nature and the wisdom of Providence.® In 1739, thanks to the protection of one of the king’s ministers, the comte de Maurepas, and to a convergence of favorable circumstances, Buffon obtained the important post of steward of the Jardin du Roi. He did not immediately abandon his work in mathematics and physics. In 1747, his experiments on converging mirrors broadened his reputation among the public. But the core of his activity would henceforth be devoted to his administration of the Jardin and the preparation of his Histoire naturelle, the idea of which Maurepas may have furnished in asking him for a Description du cabinet du rot. In October 1748, the Journal des Savants published the outline of the work in progress: a natural history in its entirety, from minerals to man, to be set forth in fifteen volumes, the first of which was just going to press.’ The very breadth of the project already revealed an ambition quite different from that of scientists like Réaumur or Trembley. The promise of the “Discours sur la maniére d’étudier et de traiter |’ histoire naturelle” demonstrated the dogmatic, perhaps even revolutionary, intentions of the author.

428 THE PHILOSOPHERS SCIENCE , In reality, this initial discourse,“ whose procedure is rather awkward and whose language is at times ambiguous, opened with a banal affirmation that could scandalize no one: the immensity and infinite variety of nature ran the risk of discouraging the scientist,® or of distancing him from the data. It was very tempting to impose upon nature a factitious unity, to discover in it nonexistent analogies, and to introduce classifications into a totality whose parts were separated only by imperceptible shadings.? No “method,” no “system” would ever be able to compartmentalize all living beings into separate categories: beings would always be found that constituted the transition between one type and another. Methods were, nonetheless, indispensable, but “one must use them only as signs agreed upon for purposes of communication. In fact, they are merely arbitrary relationships.” '° At very least, they must be based on the full range of characters displayed by the beings under classification, and not on examination of one of the parts alone. Buffon attacked Linnaeus violently on two occasions, for his botanical classification” and for his classification of animals.'* “The one true way to promote progress in science is to work at the description and the history of the various things with which it is concerned.” '> No doubt the description should be methodical and the useless and confused erudition of a scholar such as Ulisse Aldrovandi should be avoided.'* But “regarding the general order and the categorization of the different subjects of natural history, one might say that this is purely arbitrary.” '? The most spontaneous system would still be the least factitious: to distinguish animal, vegetable, and mineral, and to classify animals by element (quadrupeds, birds, and fish) and vegetation by size (trees and plants). Within the quadrupeds, “the most necessary, the most useful, will hold first rank”: the horse, the dog, the ox, and so on, then wild animals of the same climate, and finally exotic animals. This was man’s natural procedure when confronted

with all of nature’s beings: “He will study them in proportion to the utility he can derive from them, he will consider them according to their greater or lesser familiarity.” '° The classification was arbitrary, no doubt, but so were all classifications. At least this grouped together creatures that lived together: “Is it not better to have the dog, a fissiped, follow the horse, a soliped, than a zebra, which is little known to us and which may have no other relationship to the horse than that of being solipedal?” Was it less absurd to group together two fissipeds like the lion and the rat, or two solipeds like the donkey | * Now available in English as From Natural History to the History of Nature: Readings from Buffon and His Critics, ed. and trans. John Lyon and Phillip R. Sloan (Notre Dame: University of Notre Dame Press, 1981). — Ed.

Buffon 429 and the elephant?’’ All this, in any case, was of no importance: “The precise description and faithful history of each item is, as we have said, the only aim that one must adopt from the outset.” '* For description was concerned only with facts, while classification was an invention of the mind. “The one true science is the knowledge of the facts; the mind cannot fill in for it.” Up to this point, Buffon was being rather orthodox. The systematizers had occasionally been treated with needless roughness, and juxtaposing the dog, ox, and horse was somewhat contrived, but on the whole, Réaumur himself could have endorsed at least some of these assertions:”° the immensity and diversity of nature, the dangers of analogy, the arbitrary nature of classifications, the option for a useful science, the interest directed towards data and data alone— none of that was new. It was perhaps less banal to eulogize Aristotle and Pliny, praising the first for “a certain cast of ideas that I would gladly call the philosophical character” and the second for “a certain freedom of mind, a daring in thought that is the germ of philosophy.” 7’ The ancients had been little interested in detailed descriptions, concerned above all with the history of nature’s products, and always mindful of what was useful to man: “They related everything to the moral being, and they did not believe that things without usefulness were worthy of man’s concern; a useless insect whose doings our modern observers admire, an herb with no particular virtue whose stamens our botanists examine, were for them merely an insect or an herb.” ”” The eulogy is surprising in its terms, for by virtue of the criterion of usefulness, Buffon subordinated everything to the “moral” man and excluded all admiration of the spectacle of nature. What was involved here was not a banal search for the useful but rather a question of worthiness. For Réaumur, the most eminent of “our observers,” the worthiness of the insect derived from its “workings,” in which the wisdom of God shone forth. The more these workings astonished and confused the human mind and made manifest the mystery of God, the more “worthy” the insect was. The worthiness of science resided precisely in its keeping man in a state of awe, which begot humility

and trust in God. Buffon turned the perspective around. Man had to be placed at the center of nature and at the center of science, whose worthiness consisted in serving him. Nature was worthy of human attention only to the extent that it was useful to man. From this perspective, the “natural” order that Buffon decided to follow in the presentation of quadrupeds was neither so spontaneous nor so ingenuous as he lets on: it was, so to speak, an order of decreasing worthiness.”? Instead of drawing man outside of himself and leading him through awe to the feet of the divinity, the science of nature had to

430 THE PHILOSOPHERS SCIENCE bring him back to himself, and to himself as a moral being, as a being unique

and superior by essence.

The ancients had nonetheless been wrong in considering the subordina-

tion of science to man only under the aspect of utility and in underestimating “scrupulous examination and precise description.” They had not seen “the relationships that this could have with the explanation of natural phenomena. 74 They overlooked the plane of knowledge, which gave nature another kind of worthiness: Nonetheless, this aim is the most important, and one must not even today imagine that in the study of natural history one should limit oneself solely to making precise descriptions and verifying particular facts. That is the truth, and as we have said, the basic aim that one must set for oneself at the outset. But one must attempt to rise up to something grander and more worthy still of our concern—that is, the combining of observations, generalizing of data, relating them to one another through the power of analogy, and attempting to arrive at the high level of knowledge where we can judge that the particular effects depend upon more general effects, where we can compare nature with herself in her grand operations, and where we can, finally, open pathways for ourselves towards progress in the different areas of physics. A powerful memory, assiduity, and attention are sufficient to arrive at the first goal; but here something more is needed: breadth of vision, solid perception, and reasoning strengthened still more by reflection than by study; in the end, what is necessary is the quality of mind that permits us to grasp distant relationships, bring them together, and create from them a body of well-reasoned ideas, after having accurately judged their plausibilities and weighed their probabilities.”°

This passage is noteworthy, for it admirably defines Buffon’s intellectual ideal of a science that drew its worthiness simultaneously from the nobility of its aim, the grand operations of nature, and the superiority of the human faculties that it brought into play. It is easy to see that here, too, it was the

moral point of view that dominated, with Buffon raising to the level of a universal ideal the aspirations and specific tendencies of his intelligence and, deeper down, of his entire intellectual and moral temperament. Still, how might this science of “more general effects,” based on combination, generalization, and analogy, be established without replacing the diversity of things with the arbitrary unity of a human system whose dangers had been so vehemently denounced at the beginning of Buffon’s “Premier discours: De la maniére d’étudier et de traiter |’histoire naturelle”? Buffon did

not raise the question in these terms, no doubt because he did not see the risk of internal contradiction or, more precisely, because he saw nothing in common between the systems he condemned for failing to take into account

Buffon 431 the nature of things, on the one hand, and the science based on facts that he wished to set up, on the other. The true question for him was that of the method to be followed in the very establishment of science. “The greatest philosophers have felt the necessity of this method, and they have even attempted to give us its principles, and to try it out; but the first philosophers have left us only the record of their thoughts, and the others with fables of their imagining. 7° With a single shrug, Buffon had rejected Descartes, Malebranche, Spinoza, Leibniz, and perhaps Bacon as well: “No one has given us counsel, and how properly to conduct one’s mind in the sciences is yet to be discovered. *” At least, among these great philosophers, some had “risen to that high level of metaphysics from which one can see the principles, the relationships, and the whole of the sciences.” 78 Their successors had shown themselves incapable of that lofty perspective: “In this very age in which the sciences seem

to be cultivated with care, I believe it is easy to see that philosophy is neglected, and perhaps more than in any other age; the arts that people have decided to call scientific have taken its place.”?? Methods, formulas, dictionaries, in brief, scientific technologies, have replaced science, whose true nature has been lost to view. “It is more difficult than ever to recognize what we can know, and to distinguish it clearly from what we must remain ignorant of.” *°

Despite the harsh tone, the lucidity of judgment is remarkable. No one could have put his finger more clearly on the problems in which the science of 1745 had become enmired, a science that had been obliged to oppose the reigning philosophy rather than drawing strength from it, that had juxtaposed the cult of observation and an intellectualist metaphysics, and that had found itself reduced to collecting facts in a universe that it could not understand, since rationality dwelled elsewhere. No one could have underlined more sharply the philosophical demands of science or the need for a new philosophy. Buffon was not claiming to construct this new philosophy but simply to bring his contribution to the task with some reflections on the basic problem, that of truth. Refusing to play the game of metaphysical abstraction, Buffon attempted to define the nature of the truths that man was seeking to grasp. The first category was that of mathematical truths, which were “always precise and demonstrable but abstract, intellectual, and arbitrary,” for they were merely “the exact repetitions of definitions or premises,” which were themselves “arbitrary and relative.” ** Mathematics was an abstract and metaphysical science, cre-

ated entirely out of the human mind. Had it not been placed in the service of ,

432 THE PHILOSOPHERS SCIENCE physics, this science would be one “of pure speculation, of simple curiosity, and utter uselessness.” 22

“The truths of physics, on the contrary, are not at all arbitrary.” They rested upon facts or rather on a series of facts. The isolated fact, even properly observed, does not seem to have interested Buffon. “A series of like facts or, if you will, a frequent repetition and an uninterrupted succession of the same events, constitutes the essence of truth in physics” was the law to which he spontaneously reserved the name of truth. As it was impossible to exhaust the facts subsumed under a law, “what one calls truth in physics is therefore only a probability, but so great a probability that it is equivalent to a certainty,” which was to say, a moral conviction that one must not confuse with [absolute] truth, which belonged only to mathematics.** The break with Descartes was thus complete. Buffon rediscovered the “uncertain certainty” of the seventeenth-century English scientists here.>* By substituting certainty for the unattainable truth, he eliminated skepticism, which was itself merely an attitude of pure speculation and rested basically upon a confusion between two orders of truths. “It is sufficient that a thing always happen in the same fashion for it to create a certainty or a truth for us.” *? That this truth possessed no metaphysical guarantee, and that it was a truth only “for us” was no cause for regret: it was the very condition of our knowledge. We were equally constrained in the search for causes. What we called a cause was merely the effect of another cause. We ourselves were part of the system, and our senses were “themselves the effects of causes that we do not know ... ; we shall therefore have to restrict ourselves to calling a general effect a cause and give up knowing anything beyond that.”*° There was no first cause in science, and Buffon did not wonder if a first cause drawn from the “nature of things” would be more accessible than a first cause drawn from the will of God. Our knowledge was thus doubly limited, but, such as it was, it was our knowledge, and it was a possible knowledge: _ These general effects are for us true laws of nature; all the phenomena that we recognize as deriving from these laws and depending upon them, are so many explained facts, so many understood truths; those that we cannot relate to them are discrete facts that have to be placed in reserve until such time as a greater number of observations and longer experience will teach us other facts and reveal to us the physical cause—that is, the general effect from which these particular effects derive.*”

As for the use of mathematics in physics, it served only to increase the degree of probability: if the measurable variations of two phenomena were linked through a constant mathematical relationship, it was very probable

Buffon 433 that one was the cause of the other: a physical probability verified in this fash-

ion became a certainty. But this method was scarcely applicable to discrete objects “lacking in physical qualities,” such as those furnished by astronomy and optics. In trying to use mathematics in “excessively complicated physical subjects” — and Buffon was thinking above all of biology—one risked substituting an abstract entity for a real object.** In the natural sciences, one had to gather and multiply facts through observation, generalize them and tie them together through analogies, which was to say, formulate the law, and finally seek verification through experiment.*? The rest was a matter of exposition,

which depended upon each author’s particular cast of mind. | It is evident that this initial “Discours” did not stick with the promise of its title, and that it might even have greatly disappointed those who were expecting to find in it advice on handling a microscope or on the art of preserving insects, in the spirit of Réaumur and the abbé Jean-Antoine Nollet. Prefaces extolling the merits of experiment were doubtless the current thing, and Réaumur himself had not hesitated to philosophize at the beginnings of his works. Placed as it was at the outset of the Histoire naturelle, reflections as methodical and abstract as Buffon’s nonetheless acquired a rather unusual character. Above all, however, they supplied the philosophical charter of the new science. Buffon was limiting and guaranteeing the solidity of the value of knowledge in a double move. He was giving up on Cartesian evidence, on the dream of a universal mathematics, and on a universe accessible in its essential reality to human reason; at the same time, he was refusing to subscribe to the radical skepticism that condemned man to knowing only isolated phenomena, under the pretext that he could not reach the essence of things. He was simultaneously excluding illusory hopes and excessive disenchantment. By lifting the spell that mathematical evidence had exerted upon minds, he avoided discouragement and renunciation. In the course of the three stages of scientific work— observation, reasoning, and experience—he was maintaining both the power of reason and the primacy of fact, the right to the use of analogy and submission to observation, reintegrating what had been sundered and shattering the classical opposition between rationalistic dogmatism and observational skepticism. But in this revolution, science ceased simply to be knowledge or ignorance of the world as it was; it became knowledge of the world by man and doubly relative to the nature of man: first of all because it was the law and not the fact that constituted the truth of physics, and it was the human mind that formulates the law; then, because man depended upon _ his senses and all knowledge was bound up with the manner in which he was

| 434 THE PHILOSOPHERS SCIENCE informed of the world. But the very functioning of the senses was a physical phenomenon, and man himself was part of the universe that he was studying. He was no longer an alien observer, confronted with a spectacle that he was either capable of understanding or not. He was in nature, which justified Buffon’s writing his Histoire naturelle de l'homme but added yet another degree of relativity to his knowledge of things. Nonetheless, the assertion of this relativity occasioned neither skepticism nor despair in Buffon, because man’s science was made for man such as he was (i.e., for man in the world), and because Buffon, so to speak, placed man at the center of knowledge, just as he placed him at the center of the world.

IT IS MOST EVIDENT that this conception of science was intimately related to Buffon’s idea of man. In this light, the Histoire naturelle de homme, also published in 1749,*° makes possible a better understanding of the initial “Discours.” In it one finds two sets of opposed assertions, whose contradic-

tion, moreover, is not clearly resolved. For on the one hand, Buffon was an empiricist, and the famous pages in which he shows us a man awakening to the world, and to himself, prove that for him it was sensations that gave birth to ideas.*’ This dependence of the mind on the senses was far-reaching: “One man may have much more wit than another” simply by reason of having been able to exercise his sense of touch earlier.4? It was even tempting to think that intellectual development was bound up with the existence of the hand, since “animals that have hands seem cleverer,” and since monkeys were capable of imitating the “mechanical actions of man” *— of the very man of whom we already know “that he must place himself in the class of animals, which he resembles through all that is material in him; and perhaps, indeed, their instinct will seem [to us] more certain than his reason, and their industry more admirable than his crafts.” 4* The note struck here is a familiar one, echoing the Epicurean tradition of the late seventeenth century. Buffon had absolutely no intention, however, of humbling man in comparison with animals: “Everything in man indicates, even externally, his superiority over all living beings; he holds himself erect and high, his stance is that of command, his head gazes on the sky and presents an august face imprinted with the sign of his worth.” # This worth was conferred by thought: “To be and to think are one and the same for us.” © Without tackling the problem of Buffon’s spiritualism here,*” it may be said that for him, thought was of different nature from the physical agitation that brought sensation into being.** If the idea came from sensation, intellectual activity was inde-

Buffon 435 pendent of it: take away the senses of sight, touch, and hearing from man, and “thought will still manifest itself inside of him.” 4 In the end, Buffon was paraphrasing Descartes,” maintaining that the existence of our souls was

more certain than that of our bodies and the external world.’ The superiority of man to animals was not only attested by our knowledge of ourselves,

however. Thought was made manifest through language; animals did not speak, whereas “the wild man speaks just like the civilized man.” *? Reason, which invented and progressed, went far beyond the automatic mechanisms of instinct.°? Finally, one had to agree “that the dullest of men is sufficient to direct the smartest of animals, he rules over it. . . less by force than by natural

superiority, whereas one animal species had never been known to domesticate another.*4 In brief, one needed only to look at a man and a woman: “Everything in both of them proclaims them masters of the earth.” To this it may be added that if Buffon’s lengthy study of “Variétés dans l’espéce humaine’ furnishes lovers of the exotic with a fine collection of bizarre customs, it no less strongly asserts the fundamental unity of the human species:°° “In the beginning, there was only one species of men, which having multiplied

and spread out over the entire face of the earth, has undergone different changes.” °’ We have come a long way here from Ted/iamed and species of men with tails.°8

Buffon’s anthropology, like his theory of knowledge, thus rested upon his joint belief in the relativity and the greatness of man. In his own fashion, he might have said with Pascal, “If he rises up, I humble him; if he humbles himself, I raise him up.” Man was neither angel nor beast, nor pure spirit illuminated by innate ideas, nor an inconsequential animal wandering in the gloom of matter, nor an insect crushed by the majesty of divine Creation. Buffon dissociated himself just as much from Descartes as from Lamy or Voltaire. In 1749, that meant above all that he rejected skepticism, whether atheistic, deistic, or even Christian in the fashion of Réaumur. It meant that he restored to man his greatness and the dignity of his reason, in the domain of knowledge as in the hierarchy of created beings. Perhaps most remarkable of all, however, was the fact that Buffon’s reflections remained within the purview of science. They constituted a factual argument, whether drawn from inner feeling or from:an external comparison between man and animal that demonstrated man’s superiority. No metaphysical argument had been invoked, and Buffon had said nothing about the true nature of the soul, its destiny, or even its origin, except to make a furtive allusion to “the goodness of the Creator.” °? He had remained within science, but that meant that he

436 THE PHILOSOPHERS SCIENCE had remained inside nature, which man had to know in his own fashion, and upon which he could act according to his powers without, apparently, being concerned to know whether his knowledge was supposed to find a divine order therein, or whether its action and power corresponded to the decrees of Providence. Buffon had not been content to offer his personal solution to the eternal problem of the relations among God, nature, and man: he raised the problem differently by refusing in practice to have God intervene.

THE CLOSING LINES of the “Discours de la maniére d’étudier et de traiter histoire naturelle” had projected three “discourses” that were to be “trials” of the new method: on the theory of the Earth, the formation of the planets, and the generation of animals. We would not have to concern ourselves with the first two if Buffon, following a habit that he would maintain until his death, had not ceaselessly combined his scientific reflections with reflections on the power of the human mind and on scientific method. Let us note here only the determination to remain within nature, the refusal to “mix physics with theology” —for example, to introduce into the history of the earth a flood “produced by the direct will of God.”°' Newton him-

: self had been wrong in attributing the movement of the planets directly to the Creator’s hand, for “one must as far as possible, in physics, abstain from having recourse to causes outside of nature.” ®* (Let us note in passing that Buffon’s cosmogony conformed exactly to the wish expressed by Maupertuis _ in his “Essai de cosmologie.”)°? Newton had been wrong, too, in having recourse to final causes.°4 And even while remaining within nature, one ought not to invoke catastrophic, exceptional, and unforeseeable causes: “Effects that occur every day . . . , constant and ever-repeated operations, those are our causes and our reasons.’ © Finally, Buffon respected the principles he had advanced: an account of the facts preceded the explanatory hypothesis, and the hypothesis stopped short where there no longer were comparable facts — that was why the origin of comets remained unexplained. Moreover, Buffon strongly underscored the difference with the “physical history” of the Earth, on the one hand, and the “hypothesis” of cosmogony, “where only possibilities can enter in,” °° on the other. His contemporaries might have paid more attention to this distinction. The Histoire des animaux returned more than once to these problems. Buffon once more affirmed the relativity, but also the legitimacy, of our knowledge: “Whatever the case with our manner of being or of feeling, whatever the

Buffon 437 case with the truth or falsehood, the appearance or reality of our sensations, the results of these same sensations are no less certain in relation to us.’ °”

Moreover, the place we assigned in the hierarchy of beings to man, ani- , mals, and other products of nature had this same relative and legitimate character: “Although the works of the Creator may be in themselves all equally perfect, the animal is, as I see it, the most complete work of nature, and man is her masterpiece.” ©® “We can thus legitimately assign ourselves to the first rung in nature.” °° We were, however, the ones doing the assigning, and we must not be the dupes of our own perspective, nor even of the parameters of our minds. Our concepts of the simple and the composite belonged specifically to us: “A triangle, a square, a circle, a cube, etc... ., are things for us,” but “these figures are merely our creations . . . , they are perhaps not found in nature.” “We thus everywhere take the abstract for the concrete and the real for the composite.” ”° The abstract was the product of our intelligence, however, and “the real will never be produced by the abstract.”’”! This was what doomed the philosophy of a Plato or a Malebranche without hope of appeal: “What could be more simple in design than such a philosophy! What views could be more noble! But what emptiness! What a speculative desert!” ’* “Is

it in fact all that difficult to see that our ideas come only from the senses” and that “anything that does not relate back to a perceptible object is vain,

useless, and false in application?” Could one not see that: , our mental abstractions are merely negative entities, which even intellectually exist only through the abridgment we make from perceptible qualities to real entities? This being the case, is it not evident that abstractions can never become principles either of existence or of real forms of knowledge; that on the contrary, these forms of knowledge can stem only from the results of our sensations, once the results have been compared, put in order, and sequenced, and that these results are what one calls experience, the unique source of all real science, that the use of any other principle is a misuse, and that every edifice built upon abstract ideas is a temple to error?”?

slaves,

We must never forget, then, the negative character of our abstract and general ideas, or else we should take the word for the thing, and we should be its because once this word has been accepted, we imagine that it is a line we can draw between the productions of nature, that everything above this line is in fact animal, and that everything below it may only be vegetable, another word as general as the first, and that is similarly used as a line of demarcation between organized and inert bodies. But as we have already said more than once, these lines of demarcation do not exist in nature.”4

438 THE PHILOSOPHERS SCIENCE Among these abstractions, the most fearsome were final causes, which even the authority of Leibniz and Plato “cannot keep from looking small and precarious to our eyes.” Indeed, What is sufficient reason? What is perfection? Are they not moral entities created by purely human views? Are they not arbitrary relationships generalized by us? On what are they based? On moral fitnesses, which far from being able to produce anything physical and real, can only alter reality and confuse the objects of our sensations, our perceptions, and our knowledge with the objects of our feelings, our passions, and our wishes.”°

As for utilizing final causes in order to reply to factual questions— “for example, why are there trees, why are there dogs? Why are there fleas?” — this was tantamount to taking “the effect for the cause.” For “since the relation-

ship that these things bear to us has no influence at all upon their origin, moral fitness can never become a physical reason.” ’°

, “Much could be said on this subject . . . but it is not my intention here to construct a philosophical treatise.”’” Buffon was nonetheless unable to keep himself from getting carried away by anger. He knew that in order to build

the science of his dreams, he had to break with the intellectual habits of his time and impose a new philosophy upon scientists, precisely so that science might be independent of philosophy. He wanted to undo the obsession © with the absolute and take up residence in the relative. His intent, then, was staunchly antimetaphysical, as is made clear by both his conception of man and his theory of knowledge, as well as by the manner in which he established them on the basis of observed facts. He was not seeking to resolve the problems that his contemporaries discussed but to set them up differently. He did not take the divine order and the created universe as his point of departure in order to establish the real place that man occupied within them. He was not aiming to determine who among Lamy, Voltaire, and the abbé Pluche was right. He was not attempting to see the universe through the eyes of God and did not lament being unable to do so. He took man as his point of departure and related everything to him, knowledge as well as the order of the world, which could never be anything other than the order seen by man in the world, but that nonetheless would be a true order in relation to him. Still, if Buffon was refusing to frame the problems as his contemporaries did, it was because as far as he was concerned, he had resolved them beforehand—and, at least on the practical level, in the same terms in which they were being framed during his time. In 1749, to reject metaphysics was still a way of doing metaphysics. To reject final causes, to enclose oneself within

Buffon 439 | science and exclude God from it, still amounted to the adoption of a certain religious attitude.”* Relating everything to man meant cutting man off from God and His Creation. Buffon’s contemporaries were not fooled—neither the Christians, whether scientists or apologists, who immediately found Buffon’s religion suspect, nor the philosophes, who immediately recognized him as one of their own. Later on, however, some of the latter, for lack of understanding and without having grasped his originality, would be amazed by his confidence in man and in human reason, a confidence in which they were to believe they had found a contradiction.

II The Theory of Generation

If the Histoire naturelle de [homme and even the “Théorie de la terre” tended to alarm Christians, the theory of procreation set forth in the Histoire des animaux was not such as to reassure biologists. To put it bluntly, the volume created a scandal. Maupertuis’s Vénus physique had been able to pass

for an ingenious and inconsequential hypothesis, inasmuch as it was amateur trifling. However, Buffon was an official naturalist who was spouting his paradoxes in a tone of certainty. Above all, the theory itself was in appearance clear and in reality obscure. It was too easy to take its formulations at face value and to underline its absurdity. There would have been greater merit in seeking to understand its spirit and to criticize the deeper contradictions that were its weakness. But Buffon’s contemporaries were consummately unable

to perceive those contradictions. They accordingly did not go beyond the superficial difficulties, which were not lacking in an awkwardly constructed text whose assertions seemed arbitrary or were based upon debatable and illinterpreted observations. Nonetheless, Buffon cannot be accused of having thrown together his system in haste. As early as 1733, he had been discussing the problem of procreation with Louis Bourguet, even criticizing his interlocutor for maintaining something he would himself come to accept, the presence of spermatic animalcules in the female seed.”? Possibly at that early date he was embrac-

ing a sort of ovo-vermist system, in which the spermatozoa and the eggs “formed the living point, to which through forces of attraction . . . the other parts came to attach themselves in a systematic and relative order.” *° Buffon already believed, then, in a kind of epigenesis, but the “living point” — egg or

440 THE PHILOSOPHERS SCIENCE spermatozoon — that served as a basis for organization was provided by one of the parents alone, and hybrids thus remained unexplained. This forced Buf-

fon to abandon the theory.*’ One might perhaps look here for the influence of Maupertuis, whose strong interest in the data of heredity has been assessed above, and with whom Buffon discussed the issue at length, apparently starting before 1744.* It would be at that time that he stopped believing in the eggs of oviparous animals and in spermatozoa. At the beginning of 1746, he composed the first five chapters of the Histoire des animaux, in which his entire theory is expounded.*? By the time of his encounter with Needham, the system was completely in place,** and their collaborative observations could only provide additional proofs. The last six chapters and the “Récapitulation” are dated May 27, 1748. Thus Buffon had been preoccupied with this question for at least fifteen years, and the rather clumsy mode of exposition can be explained only by a desire to emphasize, not the steps in his thinking, but the originality of his ideas.®°

“Let us gather facts in order to get ourselves thinking [pour nous donner des idées).” Buffon’s procedure is perfectly summed up by this famous sentence from the Histoire des animaux.** It was not a matter of saying why living beings reproduced: that was a “question of fact” and therefore insoluble, ex-

cept through vain speculations as to final causes. But neither was it a matter of saying How each animal or vegetable species reproduced: “All these stories about procreation, even when accompanied by the most precise observations,

teach only facts without indicating the causes.” Now the sole interest facts could have was to give us ideas about the causes or, more specifically, about the general cause of the phenomenon. The real question was, “What, then, are the hidden means that nature might be employing for the reproduction of beings?” *” To a question of this kind, one could only answer with a hypothesis,** but it was a hypothesis that might be applicable to all procreation. As for the facts, Buffon took them where they were to be found—namely, in those “stories of generation” that could not indicate the causes. In the first five chapters, there is only one passing allusion to personal experiments,®? but

the fifth chapter, the longest of all, is devoted to an “exposition of theories of generation” that reports in minute detail on the relevant experiments performed over more than the preceding hundred years. It was through a careful and critical reading of the observations of Fabrizio d’Acquapendente, Harvey, Malpighi, Régnier de Graaf, Steno, Leeuwenhoek, Verheyen, and Vallisneri, as well as recent observations whose authors are not named, but were known to everyone— Trembley, Bonnet, Jussieu, and others —it was through the as-

Buffon 441 sembling of all these facts observed by others that Buffon sought to “get himself thinking.”

THE FIRST ofthese thoughts was that procreation was a single phenomenon, and that an explanation valid for all the forms it took, from the reproduction by cloning of a vegetable or polyp all the way to the sexual reproduction of mammals and birds, had to be sought.”° Now, in order for one living being to produce another like it, it had to contain it. If a willow branch or a piece of polyp could produce a complete tree or animal, it was because they already contained it. An assertion oddly reminiscent of the views expressed by Réaumur concerning the regeneration of crayfish legs or polyps was thus reached: Considering organized beings and their reproduction from this point of view, an individual is merely a whole uniformly organized in all its internal parts, a composite of an infinite number of like shapes and like parts, an assemblage of germs or tiny individuals of the same species, which can all develop in the same fashion, according to the circumstances, and form new wholes composed like the first.??

A living being was composed, then, of like beings, exactly as “a grain of sea salt is a cube composed of an infinite number of other cubes.” ”* If we could not conceive of the former as easily as the latter, it was because our ideas on the simple and the composite did not “coincide with the reality of things.” ”° Did this mean, as the abbé de Lignac was to claim,‘ that the eye of a horse was composed of little horses? First of all, this idea was valid “only for animals and plants that can multiply and reproduce by means of all their parts,” ”° which was to say, for those “whose organization is the simplest of all... , for this is merely a repetition of the same form, and a composition of like shapes all organized the same way.” A body whose organization was more perfect was composed “of parts all organic, to be sure, but organized differently.” Its reproduction would be more difficult, for it “contains only a few parts similar to itself... , that can arrive at a second development” — namely, only a few germs enclosed in the organs of generation.?° A horse was not constructed like a polyp, since it could not reproduce through cloning. Moreover, it is obvious that Buffon was deceived on this point, as on others that we shall see, by the geometric images he used to make himself understood, or, more precisely, his thinking was deeply distorted by a geometric representation of phenomena, which he could not manage to rid himself of. An animal was not constituted by the bringing together and juxtaposition of tiny animals externally similar to the large one, for it would then be necessary to accept that

442 THE PHILOSOPHERS SCIENCE these tiny animals preexisted the large one, and Buffon rejected that notion out of hand. A simple creature, or one presumed to be so, like the polyp, had to be understood, I believe, as constituted of like parts whose internal organization reproduced that of the complete animal. Isolated from the whole, such a part would be able to grow by assimilating other matter, which was to say, by imposing upon it its own organization, which was that of the animal of origin.?” But Buffon was unable, despite his efforts, to free himself from a mechanistic and spatial representation of organization, and his entire theory of procreation suffered from this basic flaw. In order that the germ, in developing, become a complete animal, it had already to be that animal, with all its parts materially and actually formed. Buffon conceived of the germ exactly as did the partisans of preexistence. Nonetheless, he absolutely rejected preexistence. It assumed the encase-

ment of an infinite, or rather indefinite,?* number of germs, one inside another, and forced us to imagine germs of a quickly implausible smallness.” On a deeper level, it was incompatible with Buffon’s notion of the methodological and moral obligations of the scientist: to say that the reproduction of living beings had already occurred “means not only admitting that one does not know how it occurs, but also renouncing the will to conceive of it.”1°° It was tantamount to making them “a direct effect of God’s will,” which was to say, one of the “questions of fact for which it is impossible to find reasons.” '°! Finally, on the biological level, it required an absolute difference between the germs that carried their posterity and those that had no posterity, and, above all, it did not allow comprehension of the joint resemblance of a being to its

father and its mother.!” , ,

Germs were formed then, but how? If among the plants and simple animals they were contained in the adult being, it was because they were formed inside and by it. Buffon thus again took up the theory of preformation that we have long seen juxtaposed to preexistence. He picked it up even in the image of the “internal mold,” which he possibly borrowed from Bourguet, but which we have already noted at the end of the seventeenth century.’? Here more than ever Buffon was a prisoner of his geometric vision of things. He saw clearly what was contradictory in the very expression “internal mold,” for a mold acted specifically on the exterior alone of the metal poured into it.!°4 The internal mold gave matter its internal, not just its external, configuration. But the image faithfully expressed Buffon’s thought, for here again the organization imposed by the “internal mold” was merely a certain arrangement in space of material particles.

| Buffon 443 The entire body of the simple animal and the different organs of the more complex animal-were therefore “like so many internal molds,” whose primary role was to ensure nourishment and growth. Like all partisans of preformation, Buffon brought together nourishment and reproduction, since it was always a question of giving the form of a living being to external matter.’ In the nutritional process, the internal mold itself absorbed the assimilated matter; in reproduction, this matter would constitute another being like the first. But in every case, the internal mold was inert and passive. So that the matter to be assimilated might penetrate it, join with it, “or rather incorporate itself intimately with it,” one had to assume “that there exist in nature forces, like those of weight, which are relative to the interior of matter, and

that bear no relationship to the external qualities of bodies, but that act upon | the most intimate parts and that penetrate into all points.” !°° These “penetrating forces” were unknowable to us: “They are not of the class of things that we can perceive,” for our senses could “represent to us only what is occurring on the outside.” They nonetheless existed,'°’ and Buffon foresaw the accusations of “those who have adopted as the foundation of their philosophy only the acceptance of only a certain number of mechanical principles,” without seeing “to what extent they narrow the scope of philoso-

phy, and... that for one phenomenon that might be related to them, there might be a thousand independent of them.” ’°* Cartesian mechanism was admirably daring, but its clarity was illusory and one ought not to reduce the qualities of matter to the small number of those that our senses allowed us to recognize. The criticism leveled here was already traditional, and it authorized Buffon to broaden his own variety of mechanism by endowing it with these “penetrating forces” conceived in the image of universal attraction,!? magnetic attractions, and chemical afhnities."°

Up to this point, Buffon had done no more than repeat, clarify, and broaden—following Newton’s example—the theory of mechanistic preformation. External matter, moved by the “penetrating forces,” flowed into the “internal mold,” was absorbed into it in order to make it larger, or separated from it in order to form another, like being. This broadened mechanism had remained strictly mechanistic; the “internal mold” was as passive as a smelter’s mold. External matter entered into it through the action of penetrating forces as bronze filled a mold through the action of weight. A preformationist scientist of 1690 would no doubt have been perfectly content with these images. Buffon did not remain content with them, however, and this is noteworthy, for the theory should have satisfied a mechanist. However, if

444 THE PHILOSOPHERS SCIENCE Buffon remained mechanist enough to conceive of organization as the establishment of a certain arrangement in space, he was no longer sufficiently one, it would seem, to be able to entertain the idea that particles of brute matter juxtaposed in a certain fashion could form a living being. If a geometric organization did not suffice to make life appear, as had already been objected by Nehemiah Grew (whom Buffon was possibly recalling), then life had to come from elsewhere. This was the only reason that could have led Buffon to the hypothesis of “living, organic molecules,” a hypothesis whose gratuitous character has often been noted, but that was especially strange, and even contradictory, in a mechanistic biology. For if it were true “that there are in nature an infinite number of organic parts currently existing, living, and whose substance is the same as that of organized beings, as there are an infinite number of brute particles similar

to the brute bodies that we know,”!! if it were true that in nutrition these organic parts separated themselves from brute parts, and that “animal matter and vegetable matter have the same nature of that animal or vegetable,” and , finally, if it were true that in nutrition these organic parts were indestructible, that “their existence is constant and unvariable, that the causes of destruction merely break them apart without destroying them,” !!3 then had one not to admit that there were two matters in nature, brute matter and living matter, rigorously heterogeneous and without any other relationship between them than mere proximity? That being the case, was it not licit to wonder whether living matter was eternal or was specially created by God? And if one had to

accept in addition that in the process of nutrition, “each part of the organized body, each internal mold, accepts only the organic molecules proper to it,” 4 had one to believe that there had existed from all eternity, or that God had Himself created, organic molecules proper to each organ of each animal? It would have been simpler to return to the preexistence of germs. And even without raising indiscreet questions, how could one reconcile the existence of a particular organic matter with the peremptory assertion at the end of the first chapter of the Histoire des animaux: “The living and animate, instead of being a metaphysical level of beings, is a physical property of matter”?" This assertion was so important in Buffon’s eyes that he reproduced it verbatim in his table of contents."° The difficulties raised by this theory of organic molecules, whose existence Buffon was content to affirm, while taking care not to

indicate their origin, are evident. , It was there, however, that the principal difficulty lay, and all that was needed to resolve it was to say that organic molecules could be born spon-

Buffon 445 taneously from brute matter. Buffon did not say this. He went no further than to say that “nature in general . . . seems to tend much more towards life than towards death; it seems to be seeking to organize bodies as much as possible”;!!” that “nature does not tend towards the creation of the inert but the organic’; that “its principal intention is in fact to produce organized bodies, and to produce as many of them as possible”;"* or, again, that “the organic is the most ordinary work of nature, and apparently the most effortless for her.” '!? Finally, all matter was or had been organic, and “the brute is simply the dead.” !”° Therefore, one might hold that organic molecules were the primary productions of a nature that tended to organize brute matter. In that case, however, it was difficult to see the usefulness of the intermediate stage between brute matter and organized beings. Perhaps Buffon did not dare to revive the spontaneous generation of living beings in a pure and simple sense. One may, however, also see in the hypothesis of organic molecules the influence of an atomistic vision of nature, extended by analogy from brute to living matter,'”* and also perhaps the influence of Maupertuis. Refusing to endow all material particles with an elementary psychic awareness,'?* but unwilling, despite everything, to resign himself to conflating the living with the inorganic in the present state of affairs, Buffon found in his living organic molecules a convenient intermediate stage. Later on, his thought would become more precise regarding these molecules: in 1765, he would intimate that they had been formed by the action of heat.’?? In 1779, he would state clearly that they had been born of a chemical operation, by virtue of the effect of this heat upon “oily and ductile” forms of matter at a particular time in the history of the earth.!*4 Instead of imagining “an infinite number” of them,'”’ he would judge that there existed “a determinate quantity,” 7° and would see in this determinacy the cause of the equilibrium that held sway between the living and the brute. But in 1749 his ideas were not yet so clear, and the organic molecules above all reflected a kind of biological atomism,'”’ which in its own way expressed the predicament of a mechanism ill at ease with its own images and still unaware of the resources of chemistry. It is certain, in any case, that this theory of living molecules was to have deep repercussions and was to play an important role in the birth of vitalism.'”°

Once the internal mold, the penetrating forces, and organic molecules had been postulated, the theory of procreation offered no more difficulties. Among simple entities, such as the polyp, the organic molecules absorbed with nourishment and impelled by the penetrating forces would come together as germs, upon which the complete body of the animal, playing the

446 THE PHILOSOPHERS SCIENCE role of internal mold, would impose the organization of the species. Once freed from the creature, naturally or by accident, the germs would develop in the sense that the believers in preexistence had given the term, that is to say, they would grow by assimilating other organic molecules through intussusception. Finally, once the germ had matured, a part of the absorbed molecules would depart to form new germs, the growth process having been completed. Among more complicated creatures, but those where a single individual was still sufficient for reproduction (aphids, for example), things occurred in the same fashion, with the mere difference that each organ served as a specific internal mold, and the germs, instead of being disseminated throughout the

organism, set themselves up only in the organs destined for reproduction, where they immediately began their development.” There remained the reproduction of sexually differentiated animals such as man. It was easy to conceive how the organic molecules, having passed into the internal molds constituted by the organs, gathered together in the generative parts and composed the seminal fluid.’°° Stull, there remained the old difficulty, which Aristotle had already raised against Hippocrates: Why were two sexes needed, if

each provided a complete germ, and why did each sex not engender separately?” Buffon accepted the idea that each individual might on its own produce an organized body. Perhaps the spermatic animalcules were, precisely, agelomerations of organic molecules.’*! But these bodies did not develop: “Only those, in fact, that are formed within the mixture of the two seminal fluids can develop.” '%? Possibly the others were not sufficiently organized. In any case, it mattered little that sexual reproduction seemed needlessly complicated: because it was commonest, it had to be assumed that it was simple

for nature.33 The explanation one gave for it had the right, therefore, not to be simple; it was enough that it respected the fact of dual heredity. Bufton’s theory respected that fact, but it overlooked all those that served

as proofs of ovism and animalculism. In order to install a new doctrine, or in order, rather, to return to the old doctrine of dual seed, he had to demolish the two ruling doctrines. Where ovism was concerned, Buffon undertook a careful and critical reading of all the important texts. He was thus able to demonstrate that Harvey had not really been an ovist,!34 that no one, not even Régnier de Graaf, had found an egg in the ovary, and that the most precise observations—those by Malpighi, Vallisneri, and Méry—were more

| damaging than favorable to the doctrine.'** If the eggs of viviparous animals were in reality mere ovarian vesicles, spermatozoa, for their part, certainly existed. Recalling all the observations of them that had been made, Buffon

Buffon 447 expounded the theory of animalcules,!°° which he declared to be untenable, since the transformation of worm into man had nothing to do with the metamorphosis of insects, since the procreation of worms themselves was astonishing, and since the number of animalcules bore no relation to the number of offspring engendered, nor the size of the latter to the size of the animal. As for the objection based on the enormous and apparently needless number of animalcules, Buffon noted it for the sake of completeness but without adopting it, for “a reason drawn from final causes will never either establish or destroy a theory in physics.” '” Clearly, none of these criticisms brought up anything new against the theory of animalcules; against ovism, examination of the texts showed the fragility of the doctrine, as well as the abuse to which certain experiments had been subjected, in particular those of Malpighi.

SUCH WAS Buffon’ position in 1746. His theory had been born from a corpuscularist vision of nature; it took into account the phenomena of heredity and the recent discoveries regarding the reproduction of aphids and polyps; it was supported by a solid critique of previous systems; but in the end, it remained pure hypothesis without experimental verification. Buffon imagined that microscopic observations could provide him with such verification: if indeed the organic molecules gathered together in the generative parts, one was bound to discover them there, or at least the initial aggregates formed by them. This would require three series of investigations: on the spermatozoa in order to find out if they were true animals or merely aggregates of organic molecules; on the liquid contained in the glandular bodies of the ovary to find out whether it did not contain similar aggregates; and finally, on the germs of plants, which should contain these aggregates as well.!3° On all these points, Buffon was convinced in advance of the success of his experiments, and he communicated this conviction to his recent acquaintance Needham, whose microscope he had asked to borrow, but who was anxious to be present for certain observations, as were Thomas-Francois Dalibard and Philibert Guéneau de Montbeillard. As for Louis Daubenton, he participated in all the experiments,’*? which took place from March to May of 1748,!4° except for certain observations on the seminal fluid of the ram, performed only the following October.!*! The spermatozoa were observed successively in man, dog, rabbit, and ram. They always appeared in the form of globules that detached themselves progressively from the ramified filaments, drawing behind them “an extremely delicate and very long net that impeded their movement,” 4? resembling the

448 THE PHILOSOPHERS SCIENCE oscillations of a swinging pendulum.'*? As the seminal fluid became more liquid, the globules rid themselves of their net and took on a more rapid and freer movement: “They then looked more than ever like animals . . . ; some were round, most oval, and a few others are larger at the two extremities than in the middle.” !44 Some of them changed form, others divided. The next day they were less numerous; after two days there remained “only globules, with no sign of movement.” !4° “Each of these experiments was repeated many times over and followed with all possible exactitude.” 4° When the seminal fluid appeared to be barren, it sufficed merely to cut the testicles in two and steep them in a closed jar in order to find the same globules, but without their net.!47 In this instance, they could be observed for more than two weeks and they changed form constantly, becoming progressively smaller and quicker. The fluid from the glandular bodies was observed in bitches, cows, and mares. In all the mature glandular bodies, the fluid contained mobile bodies, with or without tails.'48 In mixing the male and female fluids, one could not distinguish the mobile bodies of the one from those of the other. But this mixture produced no effect on the fluids.’#? Finally, water from the steeping of oysters or of pepper, a brew of carnation seeds, and the milt of different fishes all presented the same mobile bodies.’*° This was enough to show that Leeuwenhoek, despite his incomparable technique, had been a victim of his own theory and had unduly corrected his initial afhrmations;'*’ and Buffon could say with certainty that females as well as males had a seminal fluid, and that these male and female fluids, like the flesh of animals and the germs of vegetables, contained bodies in movement.'*? The mobile bodies were not animals, at least in the normal sense of the term: they had neither spontaneous movement, nor members, nor fixed forms; they did not reproduce; they might appear in a steeping of seeds, and certainly a plant could not produce an animal. They were therefore very elementary organized bodies, assemblages of organic molecules.'°* They were beings of the type that could appear spontaneously in organic bodies in decomposition—such as spermatozoa, wheat ergot, which could be killed and brought back to life as one wished, the “eels” in dough, and many other creatures besides that we took for true animals.!>4

WITH THIS, the existence of organic molecules was no longer a hypothesis but a certainty,’ and Buffon returned to the problem of sexual reproduction. If it required two complete sets of organic molecules, it was perhaps because the molecules coming from one individual could not define

Buffon 449 their action save by reacting with those of the other. More precisely, one might conceive of these molecules as organizing themselves around a focal point constituted by the molecules of the sexual parts provided by the other individual. Thus, sons resembled their mothers and daughters their fathers. There were obviously twice too many organic molecules, but the formation of the initial embryo prevented that of the second, and the unused molecules constituted the placenta.’°° The formation of the embryo thus proceeded through a direct gathering of the molecules, guided by “laws of affinity” that impelled them “to situate themselves where they had been in the individuals that have provided them.”'°” This gathering was, however, carried out in such a manner that all the parts were present, but in a “relative position” different from the final organization.'** Thus the initial development was “a production of parts that seem to be born and that appear for the first time.” *° It began with the essential parts—spinal column and cord, digestive apparatus—and continued on with the double parts, which appeared symmetrically on each side of an axis formed by the spinal cord. This symmetry was found among all animals; it warranted the belief that the double parts “actually derive their origin from single parts,” and it explained, too, why anomalies such as six-fingeredness were most often symmetrical: “The upsetting of the parts

appears to have been carried out with order, and one always sees through nature's mistakes that she errs to the least extent possible.” ’°° Regarding teratisms, Buffon considered the supposed action of the maternal imagination to be a pure invention: the famous child born beaten to a pulp was rachitic or suffering from hereditary syphilis. Both monsters and normal beings were

in the order of nature: “In the infinite number of combinations that matter can take, the most extraordinary combinations have to occur, and indeed do occur, but far more rarely than the others.” It was a matter of probability, and

one might wager that out of a certain number of children, some would be born with two heads or four legs. But people would go on believing in the influence of the mother’s imagination: “The accepted notion, especially when based upon the miraculous, will always triumph over reason, and it would be a poor philosopher who was astonished at that.” !©

After two chapters thus devoted to the specific problems of sexual and especially human reproduction, Buffon closes with a recapitulation of his general theory. Needham’s influence is palpable: the organic molecules played the role of “active force”; they were “involved” in brute matter, in the “oily and saline particles,” and when they disengaged themselves from it, for example

in the steeping of seeds, they formed an “active and exalted matter.” But in

450 THE PHILOSOPHERS’ SCIENCE the main, Buffon remained faithful to himself, and his final sentence recalled the two essential truths that he wished to establish: “There are therefore no

preexistent germs, no germs contained to infinity one within the other; there is rather an organic matter, ever active, ever ready to mold itself, to be assimilated, and to produce beings similar to those that receive it.”'©? It is as though Buffon wanted to underscore the deep contradiction in his thinking one last time.

FOR THE WEAKNESS of this theory of generation did not derive from the mistakes that Buffon and Needham might have made in their microscopical observations. These were doubtless clearly faulty. Despite the precautions taken, the spermatozoa discovered in the ovaries of a bitch had to have come from previously examined dog sperm. Or, more likely, they were not sperma-

tozoa. For the basic mistake had to do with the form of the spermatozoon and the nature of its tail, considered to be an appended filament that quickly fell off. This being the case, any microscopic creature that was round or oval in form could be taken for an analog to the spermatozoon, and Buffon could not have failed to find some of them everywhere. The preconceived idea he had adopted regarding the spermatic animalculus could only favor this observational error. However, the most accurate observation at that date could not have kept Buffon from taking a microscopic being for a bundle of organic molecules. His theory had been put together in advance, and he himself had been rather naively eager to advertise this. The weakness was in the theory

itself, then, and in its fundamental postulates. |

Now, the point of departure of this hypothesis was the rejection of the preexistence of germs, a rejection motivated on the scientific level by the data of heredity but, still more inescapably, on the philosophical level by the desire to remain within nature and to avoid all recourse to God, who eliminated all

possibility of explanation. It was therefore necessary to establish epigenesis, but what was to be its regulatory principle? Buffon did not envision the possible intervention of a spiritual principle in the manner of Ralph Cudworth or Georg-Ernst Stahl. He refused to accord particles of matter the elementary psychic awareness that Maupertuis was to lend then. He could therefore accept only a purely mechanistic epigenesis, in the manner of the lateseventeenth-century Epicureans. But in the first place, the clarity and proofs of Cartesian mechanism were no longer available to the mechanism of 1750. By bringing in “penetrating forces” imagined on the model of Newtonian attraction, Buffon made this variety of mechanism less summary but impene-

Buffon 451 trable. Moreover, this enlarged mechanism was not even sufficient to direct a true epigenesis, as Maupertuis in turn was to realize. Buffon therefore readopted the ambiguous image of the internal mold, and this, through the mediation of Bourguet and the Epicureans of 1700, linked him far more closely to the preformationists of 1625 than to Descartes. Could one even still speak of epigenesis in designating the instantaneous formation of the germ that occurred at the moment of the mingling of the two seminal fluids through the gathering together of the molecules that had received the imprint of the two internal molds? Buffon’s predicament is apparent when he describes the development of the embryo for, despite certain formulations that might lead one to believe in a true formation of as yet nonexistent parts, it was a question rather of the emergence of already formed parts, in other words, of the development of a complete germ in the sense in which the partisans of preexistence understood it. The only difference was that the germ did not preexist; rather it was formed instantaneously and completely upon the mingling of the two seeds. Nonetheless, the essence of biological mechanism was to see life as the result of a certain arrangement of material particles. The first adherents, at least, of the preexistence of germs agreed on this at the very moment when they asserted that this arrangement could not occur through the natural laws of motion. The theory of organic molecules, as Buffon expounded it in 1749, assumed on the contrary a primal living matter irreducible to brute matter. It was here that the failure of mechanism was most striking. Buffon was obey-

ing the same impulse that led Maupertuis to grant an elementary psychic awareness to all particles of matter. Anxious to remain on scientific terrain, however, he went no further than to note the existence of a form of living matter, of which he explained neither the origin nor the nature. Living nature, as Buffon presented it in 1749, was thus doubly ordained: by organic molecules, which excluded the passage from brute to animate, and by the internal molds that maintained in living species an order incapable of being disturbed by the spontaneous appearance of accidental and ephemeral beings. Still, Buffon did not go beyond noting this order; he sought neither its origin nor its end. This may have been mere methodological rigor on his part. But teratisms, too, were part of the order of nature. And did that order, or rather that regularity and permanence, reveal to us the organizing will of an all-powerful wisdom? “It seems that everything that can be, is; the hand of the Creator does not appear to have opened in order to give being to a certain

determinate number of species; it seems rather that it cast forth at one and. the same time a world of related and unrelated beings, an infinite number of

452 THE PHILOSOPHERS SCIENCE harmonious and contrary combinations, and a perpetuity of destructions and renewals.” 1°? This might be a merely apparent disorder; but we could “see in it only an order befitting our own nature, rather than relevant to the existence of the things that we are considering.” '°* We could assert the present existence of a living matter distinct from brute matter, the present existence of internal molds that ensured the constancy of species. But we did not know whether they were the instruments of an order willed by God, whether they were contemporary with Creation, whether they had a specific end or instead existed only because “all that can be, is,” whether they were only a lucky combination “in the infinite number of combinations that matter can take.” !© In any case, whatever the origin of the order that we discovered in the universe

might be, be it from God or from the nature of things, the instruments of this order were in nature: “There are no preexistent germs.” The theory of generation proposed by Buffon was in perfect conformity, then, with his theory of knowledge and his conception of man. It carried with it the same ambiguities and raised the same problems, always involving the relations between God and His Creation. Anarchy and chance in the production of living beings (which pure mechanism was unable to eliminate); the radical deficiency of the human mind; and the animal nature and diversity of the human species were closely related concepts, which Buffon rejected en masse. He believed in order in nature, in intelligence, in the unity and superiority of man. But neither the order of nature nor human reason needed to seek a guarantor in God: they existed as a matter of fact, not of right. I am inclined to think that at that time an attitude such as this implied something other than mere scientific prudence, and that Buffon was in 1749 for all prac-

tical purposes an atheist.'°° , II] The Quest for Order

Volume 4 of the Histoire naturelle appeared in 1753, and the seventh and final volume of the Supplément came out in 1789, a year after Buffon’s death. Although fifty years of work and thirty-six quarto volumes had not sufficed for Buffon to fulfill the program he had set himself, his legacy was nonetheless prodigious, and not even a summary idea of its riches can be given here. Details of an animal’s form or habits are closely accompanied by reflections on general problems of science, and often of philosophy, politics, and

Buffon 453 morality besides. From these dispersed morsels, it would not be hard to reassemble Buffon the philosophe, giving that word all the meanings it had in his day.’°” Only the great problems raised by the first three volumes of the Histoire naturelle are pertinent here, however, and the evolution of Buffon’s thinking will henceforth no longer be examined systematically and for its own sake. While it cannot be said that Buffon ceased being a philosopher and became a naturalist between volume 4 of the Histoire naturelle and volume 1 of the Supplément, it is nonetheless true that his thinking came to be more firmly grounded in scientific reality. The data suggested the ideas,'®* and Buf-

fon’s thinking was enriched and refined by the discovery of new objects of study. But it was above all by following his own path that Buffon developed, clarified, and perfected his ideas, finally arriving at a highly original solution to the problems he had raised in 1749.

VOLUME 4 opened oddly enough with the publication of the passages that the Sorbonne had judged reprehensible in the first three volumes, and to which Buffon now appended the requisite explanations. (The official theologians seem to have been quickly satisfied with a purely formal submissive bow, at least when it came from a man of some stature.) !®? The essential intent of Buffon’s “Discours sur la nature des animaux” was to present a new theory of the animal-machine, less peremptory than that of Descartes but just as radical. His analyses and his comparative method led Buffon to speak of man, however, and, paradoxically, the pages on wisdom and happiness in this “Discours” became famous. Buffon stressed human duality, the internal struggle between material appetites and reason, and the necessity of sheltering the soul from the passions of sentzment.'”° The soul (i.e., thought) was the lone source of human greatness, but this greatness was inalienable, whatever might have been said about it: It is not surprising that man, who knows himself so poorly, who so often confuses his sensations with his ideas, who so rarely distinguishes the product of his soul from that of his mind, should compare himself to the animals, and should accept between himself and them only a slight gradation dependent upon a greater or lesser level of perfection in the organs; it is not surprising that he should have them reasoning, understanding, and deciding like himself, and that he should attribute to them not only his own qualities, but those he lacks to boot. But let man examine himself, analyze himself, and learn more about himself, and he will sense the existence of his soul, he will cease debasing himself, and he will see at a glance the infinite distance the Supreme Being has placed between himself and the beast.!7?

454 THE PHILOSOPHERS SCIENCE Assertions such as this parried the libertine tradition and Voltaire’s sarcasm, as well as chided the pious naturalists who so admired insects. In fact, Buffon took on by name “our observers,” whose enthusiasms he wickedly caricatures. An allusion to Réaumur explains the vehemence of the passage: Buffon was getting even with the person he considered responsible for the attack on him in Lettres a un Amériquain:'”? Independently of the enthusiasm one may feel for one’s subject, one always feels greater admiration as one observes more and reasons less. Is there, indeed, anything more gratuitous than the well-known admiration for bees, or than those moral intentions one would like to lend them . . . ? For, after all, a bee should not occupy more space in the head of a naturalist than it does in nature; and that marvelous republic will never be seen in reason’s eyes as any more than a multitude of little creatures that have no other relationship to us than that of providing us with wax and honey. It is not curiosity Iam blaming here, it is the reasoning and exclamations .. . , it is the morality and the theology of insects that I cannot bear to hear preached. . .. Is nature not awesome enough in itself, without our seeking additional amaze-

ment by being stunned by marvels that are not in nature and that we put into it? Do not His works make the Creator great enough already, and do we imagine we are making Him greater, through our foolishness? This would be the way to abase Him, if such could be done. Who, in effect, has a loftier idea of the Supreme Being: he who sees Him as having created the universe, given order to all forms of existence, founding nature on invariable and perpetual laws, or he who seeks Him and finds Him attentive to the governance of a republic of bees, and highly concerned with the manner in which the wing of a beetle is to bend?!79

If personal animus explains the unusual vehemence of tone, the ideas themselves were nonetheless deeply those of Buffon, who was irritated by everything that tended to abase man and his intelligence. Thus one may assume that this passage aimed, through Réaumur, and perhaps with better justification, at all the adepts of English providentialism and insect theology—

the abbé Pluche, for example. God himself, if He existed, was the God of intelligence, the God who commanded the forms of existence and establishes the invariable and perpetual laws of nature: He was not God the Craftsman

who focused His ingenuity on the wing of a beetle. Even this intervention of the Creator is somewhat surprising, however, and all the more so in that the passage does not require it. It is as though Buffon felt the need to invoke God to give firmer grounding to the order of the world and man’s superiority. Here again we thus meet the three protagonists of our story: God, man, and nature. Nonetheless, whatever its solution, the problem of God remained in

the background: He interfered only as a metaphysical justification for the order of nature and the dual power of man, to know nature and to act upon it.

Buffon 455 The dialogue, or the antagonism, between man and nature thus becomes the major theme of the Histoire naturelle. The questions raised in the areas of morality and art need not be broached here. Only the problem of nature and the modalities of human power need detain us. It was of little concern that man misused his power by mistreating his animal slaves,!”* or that he was “the greatest destroyer” in nature,’”° “the most harmful of all species.” '”°

The important point here was: :

Man’s dominion over animals is a legitimate dominion that no revolution can abolish: it is the dominion of spirit over matter, it is not only a right by nature, a power founded upon inalterable laws, but it is also a gift from God, through which man can recognize at every moment the excellence of his being . . . ; it is by natural superiority that man rules and commands; he thinks, and by virtue of this he is the master of beings that do not think.’””

Still, this “superiority by nature,” this “gift from God,” manifested itself in man only in society. For it is from society “that man drew his power, and through it that he had perfected his reason and pooled his forces; prior to that, man had perhaps been the most timid and least fearsome animal of all.” It was only “by virtue of the arts and society” that he had been able “to march in force to conquer the universe.” '”® “Man in the wild state is merely an animal species incapable of commanding others,’ ’”? “an inconsequential being, a kind of powerless automaton.” '*° This was why the savages of the New World, who had not been able to set up societies, had “never subjected either animals or the elements to themselves.” *' And if society was necessary to man’s power, it was not because it allowed for common action in which the individual forces acted in concert. This phenomenon of mechanical addition played a role only among social insects—for example, among bees or “Cayenne flies” [Buffon’s term is mouches de Cayenne—Ed.] —where creatures born at the same time formed “a swarm that had not assembled by choice but

rather found itself brought together by a force of nature.” '** The individual

born in the bosom of a true society received through his formation the entire intellectual inheritance of that society, thanks to language, which was a social institution.!83 The social individual was thus himself different from the iso-

lated individual. In reality, however, the isolated individual did not exist in the human species, and the supposed state of nature imagined by Rousseau was a pure utopia: Unless one were to claim that the constitution of the body was completely different from what it is today, and that its growth was far more rapid, it is not possible to maintain that man has ever existed without forming families, since the children

456 THE PHILOSOPHERS SCIENCE would die if they were not helped and cared for through the course of several years;

, instead of which newborn animals need their mother for only a few months. This physical necessity alone suffices, then, to demonstrate that the human species was not able to last and multiply except with the help of society; that the union of fathers and mothers with children is natural, since it is necessary. Now, this union cannot fail to produce a mutual and lasting attachment between parents and child, and that alone suffices again for them to become accustomed among them to gestures, signs, sounds — in a word to all the expressions of feeling and need; which is proved as well by the data, since the most solitary savages possess, like other men, the use of signs and speech. Thus, the pure state of nature is an unknown state; it is the savage living in the wilderness, but living in a family group, knowing his children, known by them, using speech, and making himself understood.!84

If, on the contrary, “the child had been born in the state of pure nature, if he had as teacher only his Hottentot mother, and if at the age of two months he were sufficiently developed in body to be able to do without her care and to be separated from her forever, would this child not be below the idiot, and, as regards externals, completely on a level with animals?” “That pure light, that divine ray, which was allotted to man alone,” '*° would thus remain without effect, if the physiological growth of man were not so slow. Everything flowed from this slowness—the formation of a lasting family, language, society, social education, the perfecting of reason and the arts, and dominion over nature. Now, like causes produced like effects, although to a lesser degree, among the animals: Among the very animals, although all are deprived of the thinking principle, those whose rearing is the most lengthy are also those that seem to have the greatest intelligence; the elephant, which of them all has the lengthiest time of growth, and that needs the help of its mother throughout the entire first year, is also the most intelligent of all; the guinea pig, which needs only three weeks to complete its growth and to reach puberty, is perhaps by this sole reason one of the stupidest.!8”

Beavers gathered together into a society created admirable works. Dispersed by hunters, “they become insecure, their endowment, withered by fear, no longer blooms,” they “exercise only their individual faculties,” which were mediocre.'** The animal revealed its true talents in society, and all ani-

mals were “impelled by nature to live together, to form family groups, to constitute kinds of societies.” 18? We did not know their true nature in the degenerate state in which they lived today: What intentions, what designs, what projects can soulless slaves or powerless exiled convicts possess! Groveling or fleeing, and forever existing in solitary fashion, build-

Buffon 457 ing nothing, producing nothing, transmitting nothing, and languishing forever in calamity, declining, perpetuating themselves without multiplying—in a word, losing

through their duration in this state as much and more than they had acquired through time.!?°

The distance between man and the animals thus grew from day to day: The more the human species multiplies and becomes perfected, the more animals feel the weight of a dominion as awesome as it is absolute, which, hardly leaving them their individual existence, deprives them of all means of freedom, all notion of society, and destroys the very germ of their intelligence. What they have become, what they are yet to become, does not perhaps adequately indicate what they have been, nor what they could be. Who knows, if the human species were annihilated, to which among them earth's scepter would belong?!’

Thus, the present state of man and animals, and perhaps even the inflnite distance that separated them, and that Buffon so powerfully highlighted, would be merely the result of a history at the outset of which man was just an animal among others, but more happily endowed, by the plasticity of his species, which had allowed him to adapt to all climates; by the shape of his arms and hands; by the perfection of his sense of touch; and by the slowness of his physiological growth. In the Epogques de la nature, Buffon seems

to distinguish the creation of man from that of the other animals, but my examination of the manuscript makes it impossible for me to believe in his sincerity, and the human species must be assigned the same origin and the same history as other animals.’?* The constant affirmation of the divine origin

of reason would in that case merely have been a precaution against censorship. Even assuming that this affirmation were sincere, it is clear that Buffon was far less interested in the supernatural origin of human reason than in the natural, biological, or sociological conditions of its exercise. Here, too, Buffon’s science did without God. There was, then, no metaphysical reason why the human mind should truly understand the world. And never, even in his most daring texts, would Buffon claim to arrive at first causes. Never was he to accept final causes, which made us attribute “the purpose of our mind” to nature.’ Even when it stayed with secondary causes, our mind was the victim of our senses, and Buffon emphasized this even more clearly in 1766 than in 1749, in contrasting the mind’s movement, which “proceeds in a straight line in order to arrive at

a point, with nature’s movement, “whose every step, on the contrary, proceeds in all directions.” 194 In 1749, however, he had already claimed to be able to use the powers of reason in order to surmount the inadequacy of our senses

458 THE PHILOSOPHERS SCIENCE and our imagination with his elaboration of the notions of the internal mold and the penetrating forces. In 1766, he affirmed the legitimacy of this victory by reason: “The mind, although limited by the senses, is neither less pure nor less active thereby . . . ; it has recognized all the externals of nature and, unable to penetrate inside of it through the senses, it has divined through comparison and judged through analogy.” '”? What had disappeared in this development was the idea, expressed with such force in 1749, that human knowledge was relative to man and valid only for him. In the “Seconde vue de la nature” (1765), as in Epoques de la nature (1779), Buffon set things forth as they were. His thinking shows no relativism. The very difficulties and the immensity of nature merely redoubled the scientist’s enthusiasm: Far from becoming discouraged, the philosopher should applaud nature, even when she appears miserly of herself or overly mysterious, and should feel pleased that as he lifts one part of her veil, she allows him to glimpse an immense number of other objects, all worthy of investigation. For what we already know should allow us to judge of what we will be able to know; the human mind has no frontiers, it extends proportionately as the universe displays itself; man, then, can and must attempt all, and he needs only time in order to know all. By multiplying his observations, he could even see and foresee all phenomena, all of nature’s occurrences, with as much truth and certainty as if he were deducing them directly from causes. And what more excusable or even more noble enthusiasm could there be than that of believing man capable of recognizing all the powers, and discovering through his investigations all the secrets, of nature! !96

The Epoques de la nature, almost contemporary with this text, breathes the same joy and certainty: man was made to know the world as well as to mas-

ter it. ,

This evolution in Buffon’s thinking was reflected in his attitude to classification. His radical skepticism in 1749 regarding any possibility at all of classifying living beings has been noted. In nature, there were only isolated species. As early as 1755, however, Buffon had had to acknowledge the existence of closely related species.’*” In 1758, he condemned “the notion of genera... , which evaporates as soon as one applies it to reality,’’°* but in 1761, he accepted this idea “for difficult enumerations of the smallest objects in nature.”'?? In fact, he had already used it in practice in his 1758 presentation of bats. In 1765, he used “generic terms” to designate closely related species °° and classified the cat within the same “tribe” as the jaguar, the tiger,

and the other felines,” already attaching so much importance to the issue that he vehemently upbraided Fredrik Hasselquist for having forgotten to say whether or not the horns of the giraffe fell off annually, which prevented

Buffon 459 one from “determining its nature” —that is, knowing whether it was “of the genus of deer” or of oxen.” In 1766, the “Nomenclature des singes” classified all the animals commonly grouped under that name by genera, species, and varieties.*°* More generally still, the discourse “De la dégénération des animaux reduced two hundred species of quadrupeds to thirty-eight families.2°4 In 1770, the notion of genus became the very basis for the Histoire naturelle des oiseaux.?”°

Buffon did not, however, rally to the views of the systematizers, whom he accused more harshly than ever in the final volumes of the Histoire naturelle on the quadrupeds of distorting nature in order to fit it into artificial structures.2°° He continued to criticize the misuse of general terms, which were abstractions unfaithful to the reality of things.”°’ In order to explain an animal, it was not enough merely to place it in a system: one had to describe it, for each species had its irreducible personality.*°* There is thus no mistaking the value that Buffon attributed to classification: it ought not to be a mere artifice convenient to the scientist— it had to express the reality of things. One had therefore to condemn any method that claimed to classify animals while taking into account only one part of the body, always the same in all cases;? one had to follow a natural method calling on the greatest possible number of elements of comparison and employing different characteristics according to the species to be grouped or separated.?!° This fidelity to the real did not allow one to assign absolutely definite frontiers to genera: there were animals that “shaded into” one genus or another,”” and Buffon was always to assert — that nature proceeded by imperceptible shadings.?!? But within this continuous reality, where he had at first been determined to see only species set side

by side, now he thought it possible to discover the particular relationships that defined more general groupings than species. Buffon had given up on classifying beings according to their relationships with man, as he had done in 1749, in order to classify them henceforth according to their real relationships among themselves. He had thus now come to believe that man could grasp these real relationships and see nature as it was: the order that he discovered in it was no longer relative to the observer; it existed in things themselves. This evolution in Buffon’s thought unquestionably originated in his reflections on the notion of species. In 1753, his definition of species was simple and rigorous: two animals were of the same species when they together produced fertile individuals. All men were therefore of the same species,?!? whereas

in view of the infertility of mules, the ass and the horse were two distinct species.2!4 “Differences in temperament, nature, and habits” were second-

460 THE PHILOSOPHERS SCIENCE ary.”’? The ox was not a bison, and the dog was not a wolf or a fox.?!° This provided a fine opportunity to attack nomenclators who confused different species “for not having adequately consulted nature.” 7!” The role of the naturalist would thus be simply to record the existence and the characteristics of different species, considered as an irreducible given. This purely passive role, however, would not fit in very well with Buffon’s notion of science, which was the search for relationships and causes. Luckily, there were different varieties within species. The unity of the species postulated the unity of origin of all the varieties, whose existence thus posed a double problem worthy of the attention of the naturalist who wished to be something more than a mere namer/classifier: what was “the character of the primitive race, the race of origin, the mother race of all the other races,” and what were the causes that “alter, over time, the most constant forms?” ?"® Buffon automatically took the same attitude to animal species as to the solar system: he looked for relationships in order to find causes. The terms of the problem were stated clearly only in the “Histoire natutelle du chien” in 1755. But in 1749 Buffon had raised the problem implicitly with respect to man and had attempted to resolve it. He seems to have believed that the white race was the primitive one in the human species.””? As for factors of “degeneration,” ?*° they were clearly indicated: climate, food, and mode of existence.?*! Variations, at first individual, were transmitted through heredity, amplified and generalized through the continued influence of the same causes, and would no doubt end up disappearing if the action of the milieu came to an end or changed.’”? Buffon would have nothing to add to these pages from 1749 when he came to study “degeneration” in animal species. The action of the milieu, inheritance of acquired characteristics,

and the role of duration had been affirmed once and for all. The mode of existence, which depended in man’s case upon the level of civilization and of social organization, would depend for the animal upon its state of freedom or domestication, and would take on a crucial importance. But as far as the fundamentals were concerned, there was no more to be said. Nonetheless, the details of the history of quadrupeds furnished facts that might serve as supplementary proofs, but that raised problems as well. The

nature and quantity of nutriment acted on the conformation of the digestive organs: the large volume of grass ingested by the ox produced the large capacity of its belly,??> the large quantity of water absorbed by the thirsty camel had brought about the formation of the water pouch.?”4 Long domestication — the squatting posture that had become natural to it—was the cause

| Buffon 461 of the hereditary calluses the camel bore on its chest and legs, and even of the single or double hump that “disfigures” its back.’”° Likewise, the bison’s

hump was “less the product of nature than an effect of work, a stigmata of slavery”: oxen had humps in parts of the world where they were used as beasts of burden and were well nourished. Wild bison were “enslaved and humped oxen that have escaped or have been abandoned in the woods.” The buffalo,

on the other hand, constituted a different species, for it did not couple with the ox and had a longer period of gestation.?”° The “accidental” differences might thus be considerable, especially among domestic animals. The action of climate, food, and domestication, without being “powerful enough essentially to change the nature of these beings, whose imprint is as firm as that of the mold of the animals,” could nonetheless transform their exteriors and even their characters and instincts, their “most internal qualities.” For “one

single modified part in a whole as perfect as the body of an animal sufhces | for everything, in fact, to feel the effects of this alteration.” 7?”

The work of the nomenclator consisted, then, in recognizing the unity of the species behind the sometimes considerable diversity of appearances, thereby reducing rather than increasing the number of species.”** This would already make the species not just a mere term in an enumeration but a means of ordering the living universe by reducing several different forms to a basic

type, and, at the same time, a means of understanding it by explaining the “degeneration” of the primitive race into distinct varieties. Buffon attempted to perform this task for certain complex species like those of the ox, the dog, the sheep, and the goat. In this way, he reduced all quadrupeds to two hundred species, which constituted a sort of natural classification simpler and truer than all the artificial classifications.??? This classification was in itself doubly natural, since the individuals it subsumed were united by an actual identity of type and by a common origin. The question remained whether any link between species could be conceived of aside from those of proximity and juxtaposition. Buffon had already noted in 1755 that there was a hierarchy of sorts between related species: there were “prime species—the horse, the sheep—and “subalternate” species— the ass, the goat. These species were distinct, but so close to each other “that there remains between them, so to speak, only the space necessary to draw the line of demarcation.” 7°° They reproduced with each other, but no inter-

mediate species had ever been formed. And in fact, no one knew whether the billy goat and the ewe produced a sterile hybrid or fertile offspring. Hybrids were perhaps not always sterile. We still did not know whether “the dog

462 THE PHILOSOPHERS SCIENCE can reproduce with the fox and the wolf,” the stag with the cow, or the doe

| with the fallow buck. “Upon this determination depends, however, our complete knowledge of these animals, the precise division of their species, and a perfect understanding of their history.” ?*! Thus we could only provisionally separate the sheep and the goat. Despite all their points of resemblance, we had to separate the deer and the fallow deer, which never mated.’** But what about the roe deer, which resembled the goat and whose female gestated for five and a half months like the nanny goat: could it not “be regarded as a wild goat?” >> Things got complicated here, because it was not always possible to couple animals presumed to be of the same species, and because there might be close resemblances between animals that apparently did not reproduce together and were thus of different species. The problem was raised more clearly with respect to small quadrupeds, which Buffon studied in 1758,734 and whose species resembled one another so closely that they might be supposed to have suggested the very notion of genera to naturalists. Buffon condemned the concept of genera because it was abstract and did not take into account specific differences.”*° But his reflections on these related species were

scarcely in his usual style: “Nature has been able to find compensation for everything,” he wrote. With these tiny, vulnerable beings, she had multiplied the species; if, therefore, “one of them ceased to exist, the void in this genus would hardly be noticeable.” *** It would have been easy to find something better than this bit of finalist reasoning, all the more so in that Buffon knew perfectly well that these species, whose reproduction was rapid and multiple, contained many varieties.??” He must have reflected on this problem while going through the interminable list of small quadrupeds. He may perhaps have been struck as well by the case of the bats, whose seven “very distinct, very different” *** species nonetheless had in common an extraordinary conformation. What is certain is that in 1761, his thinking changed. He would henceforth distinguish “noble species . . . , which are constant, invariable, and which one cannot suspect of having become degraded; these species are ordinarily isolated and the only ones of their type,” such as the lion. Then came less noble species, which had immediate kin, like the horse, to which the ass was closely related. The dog was still less noble; the wolf, the fox, and the jackal, “which one may regard as degenerate branches of the same family,” were all akin to it. Finally, one descended to the tiny quadrupeds, where, since each species had “a great number of collateral branches, one can no longer recognize either the common line or the direct stem of each of the

Buffon 463 too numerous families.” Here, and here alone, recourse to genera was legitimate, whereas it was ridiculous “where first-rank beings were concerned.” *°? This text from 1761 is very important, especially in that it reintroduces the notion of the animal family, which Buffon had strictly proscribed in 1753, under the specific pretext that it was impossible to establish links of kinship among possibly close, yet irreducibly different, species.?4° At the same time, he seems to have identified family with genus, and to have made of the latter the basis for a methodical description of animals. All this is apparently clear and coherent. However, from the “Histoire naturelle du lion” to “De la dégénération des animaux, published in 1766, Buffon did not stop contradicting himself, at least on the face of it, regarding these questions, and the most evident reason for these contradictions was the fact that his thought was developing simultaneously along three different axes: that of natural history, that of biology, and that of the history of life. The notions of species, genus, and family thus took on different values, which could, on occasion, react upon one another.

ON THE BIOLOGICAL AXIS, the relations between species were very simple in 1753: the sterility of crossbreeds proved that they were foreign to one another. A careful examination of the facts, in particular those relating to the sheep and goats on which Buffon performed experiments, showed that things were far less simple. In 1755, the “Histoire naturelle de la chévre” stated

only that since sheep and goats had never produced intermediate species, they had to be considered distinct.?4! In 1764, Buffon still considered the two

species as distinct, but admitted that crossing was possible and could produce fertile offspring. The biological barrier of hybrid sterility thus no longer existed between the two species. Still, crossing was possible in only one direction: “The billy goat acts with potency upon the ewe,” whereas “the ram is incapable of reproducing with the nanny goat.” There was, then, an inequality

between the species, and it was beyond doubt that “the goat is the dominant species and the sheep the subordinate.” Moreover, in crossing the billy goat with the ewe, one ended up with “a kind of mouflon [wild sheep]... , a half-breed throwback to the species of origin, and that seems to indicate that our goats and our domestic sheep have something in common at the be-

ginning. 742 Common origin was thus not restricted to varieties of the same , species. Moreover, even within species, certain varieties involved only the males and not the females; certain races perpetuated the paternal variety and

464 THE PHILOSOPHERS SCIENCE others the maternal type, so that one could speak of masculine and feminine races, which “seem to constitute distinct species, and this is the case when it is, so to speak, impossible to set the limit between what the naturalists call species and variety.” **3 Crossings between related species might form stable races, which would be a variety within one of the species of origin.?*4 Clearly, the biological definition of the species was becoming hazier and hazier. The sterility of hybrids was decidedly a fable to be rejected: the co-hybrids pro-

duced by the horse and the ass could no doubt reproduce; those of birds certainly reproduced.”* Buffon was thus not surprised to learn, in 1773, that a dog had been able to reproduce with a she-wolf.?*¢ Since a goat was not a sheep, however, the notion of species would be preserved. But its biological meaning would be transferred to the broader notion of genus. The naturalist would need to take account of it whenever his domain overlapped with that of the biologist— namely, as regards domestic animals, upon which man had imposed artificial conditions of existence that tended to cause the nonphysiological characteristics of the species to disappear. Buffon explained his thinking on this point in a passage from 1764 that simultaneously defined the biological notion of genus as a mere broadening of the notion of species and showed what use the naturalist could make of it: Just as it seemed compellingly necessary, in composing the history of wild animals, to consider them discretely and independently of any other genus, I believe, on the other hand, that for domestic animals we must adopt and extend the genera. The reason for this is that in nature there exist only individuals and sets of individuals, that is, species, because we have not influenced the species of independent animals, while, on the contrary, we have altered, modified, changed those of domestic animals. We have thus created real, physical genera, quite different from those metaphysical and arbitrary genera that have never existed except in the mind; these physical genera are in fact composed of all the species that we have manipulated, modified, and changed; and, as all these species diversely changed by the hand of man nonetheless possess only a common and single origin in nature, the entire genus should constitute only one species.747

Thus, side by side with the articles on the wild sheep or the ibex in which Buffon gave himself over to true genetic investigations on the species of sheep and goats, the articles devoted to wild animals without domestic varieties continued to recognize only species in the narrow sense of the term. In fact, it was of little concern to the naturalist that two species were closely related, even that they could reproduce together, if in nature they were separated by seas and deserts or even merely by temperament, such as the automatic antipathy that set the dog and the wolf against each other** and separated the

| Buffon 465 deer from the fallow deer,2*? or the different kinds of bats from one another.?*°

A difference in conformation, in character, or in habitat were sufficient to define a species.”*? Hybrids were very rare in nature,”°* and in order to cross a she-wolf with a dog, it had been necessary to domesticate the former (i.e., to alter her character).”*? For the naturalist, the species thus remained the only

reality, and the genus had to be seen as no more than convenient shorthand when speaking of small animals. Buffon did use “generic terms,” but he hastened to distinguish the species covered by them. Just as he had written in 1753 that “the ass is therefore an ass, and is by no means a degenerated horse,” ?>4 he wrote in 1764: “The zebra is thus neither a horse nor an ass; it is a species of its own.” **? Not before 1770 and the Histoire naturelle des oiseaux would genus be used as a nomenclatural unit. Still, it is noteworthy that Buffon very often distinguished species, especially among the large birds, and that, since

the little species frequently mixed with one another in nature, the notion of genus could take on its biological value for them as for domestic quadrupeds. Nonetheless, the notion of family, rehabilitated in 1761 in the “Histoire naturelle du lion,” still did not seem to have any greater interest for the naturalist. In 1765, Buffon clearly separated the wolf, the fox, the jackal, and the dog as closely related but distinct species, with no allusion whatsoever to those “degenerate branches of the same family” he had spoken of four years earlier.2°° This was because the naturalist had to restrict himself to what he saw. Certain animals might have a common origin: But that must not keep us from regarding them today as animals of different species: whatever cause the difference may come from, whether it has been produced by time, climate, and the land or whether it be coeval with Creation, it is no less real: nature, I acknowledge, is in a continual movement of change; but it is enough for man to grasp her in his own age.*°7

It is noteworthy that this passage, exactly contemporary with the “Histoire naturelle du lion,” seems to condemn its conjectures on the past history of species. In fact, Buffon separated domains and distinguished facts from hypotheses, but he never resigned himself to seeing only the present: not satisfied with grasping nature “in his own age,” man had also—and this is the end of the sentence—to “cast his glances backwards and forwards, in order to attempt to glimpse what nature may once have been, and what in the future it may be.” The naturalist became a historian of life. But he would never introduce these “backward glances” into the description of the present —the “Histoire naturelle du lion” was an exception in this regard; he would save them for certain “discourses,” and especially for the famous “De la dégénération

466 THE PHILOSOPHERS SCIENCE des animaux,” published in 1766. Even if Buffon’s ideas on these problems had not given rise to endless discussions on “transformism” in the Histoire naturelle, we should have to deal with them, for what was at issue here, as elsewhere, was the possibility of man understanding nature. “De la dégénération des animaux” in fact assembled all of Buffon’s ideas on the matter, and almost in the order in which the Histoire naturelle presents them. The variations in the human species with which the discourse begins had been expounded as early as 1749. In Buffon’s eyes, these variations were in any case slight, and they might disappear in time: blacks transplanted to Denmark would regain the original whiteness of the species; but no doubt “a rather great number of centuries” would be necessary.”*? Animals were more exposed than man to the effects of climate and nourishment. Those that had varied the most were the domestic animals, transported by man at his will into all climates and fed according to his whim. Wild animals might also have been forced to change climates as a result of some vast transformation in the globe or simply in order to flee man or other stronger animals. The herbivores had varied more than the carnivores, whose nourishment was more or less the same everywhere. The small species, which reproduced more quickly and had more offspring than the large ones, displayed a larger number of vari- eties. Finally, variations were often so profound that they could no longer be erased through a return to the original milieu.”°? None of this was new, either in the fundamentals, already set forth in 1749, or in its details, all of which had been introduced between 1753 and 1764. Indeed, regarding the variations possible within species, Buffon’s thinking never changed. There follows a famous sentence: After the glance that we have just directed towards those varieties that indicate to us the particular alterations of each species, there appears a more important consideration, however, and one of broader perspective: it is that of the change in species themselves — it is that more ancient degeneration, from time immemorial, that seems to have occurred within each family, or, if you will, in each of the genera under which one may subsume closely related species without great differentiation.?©°

In order to understand the precise significance of this passage, one must know what Buffon understood by genus and family. And for that it is sufficient to see that he first listed a few isolated species that by themselves constituted genera, that he then dealt at length with the supposed sterility of hybrids, and

that he finally constituted families by gathering together species that reproduced or could reproduce with each other.”*! Therefore, one could say of these natural families what Buffon had already said of the genera created by domes-

Buffon 467 tication: “The entire genus must form only one species.” What had changed between 1753 and 1766 were not Buffon’s ideas on the evolution of species but his very definition of species. In 1753, the naturalist and the biologist had defined the species in the same fashion, by way of the unity and originality of the “internal mold.” In 1766, the biologist retained this definition, but, no longer believing in the sterility of hybrids, he could assemble in the same species very different beings. The naturalist, on the other hand, had to abandon this biological definition, which had become too broad, and use a more precise and restricted definition, into which there entered considerations of form, habits, and habitat that made the definition more properly zoological. Thus, the biologist’s species became for the naturalist a genus or family, inside of which were necessarily found “the inalterable imprint of the type” and, in addition, the effects of degeneration, which produced what the biologist would call “varieties” and what the naturalist would call “varieties” or “species,” without always being able to distinguish clearly between the two notions. The entire difficulty arose, then, from the fact that in some places Buffon used the same word in the broad sense of the biologist and elsewhere in the restricted sense of the naturalist. In the two great vues, or prospects, of nature published in 1764 and 1765, it is the broad sense that predominates. The'constancy of species was therefore affirmed without the slightest restriction. “The imprint of each species is a type whose principal characteristics are engraved in indelible and perduring characters.” ”°? This constancy of the “internal molds,” which existed in “determinate number” and endlessly assimilated “a determined quantity of organic matter’ in an “invariable proportion, *°> was one of the elements of the eternal order of nature. For if “nature is itself a perpetually living work, a ceaselessly active worker,” it “never moves away from the laws prescribed for it, it alters nothing in the plans that have been traced for it, and in all its works it displays the seal of the Eternal.” 2°4 Time existed only for individual beings; nature was outside of time, it “keeps on and will continue to keep on as it has kept on: a day, a century, an age, all segments of time are foreign to its duration; time itself is relative only to individuals.” The human species, like all species, partook of this eternity of nature, and the scientist ought not to see this nature through the eyes of the ephemeral individual but through the eyes of the species, immutable as the universe. Then the cycle of seasons and the birth and death of individuals would no longer be any more for him than particular accidents: “He sees in this destruction, in this renewal, in all these successions only permanence and lastingness. . . . He reads into the past, sees into the present, judges of the future; and in the

468 THE PHILOSOPHERS SCIENCE flow of time that leads, drags, and absorbs all the individual beings of the Universe, he finds species themselves constant and nature invariable: the relationship of things being always the same, the order of time seems nothing to him.” 26 Behind the fleeting diversity of individual beings, the eternal order

remained. It was this that science had to reach out to, and the permanence of animal species was simply one aspect of the eternity of the world’s order. It is clear how impossible it is to see in Buffon a precursor of transformism, even though he accepted a variation of living forms under the influence of milieu and the inheritance of acquired characteristics. On the biological level, the products of degeneration were for him never, properly speaking, anything more than varieties within a species. One could relate the peccary to the pig

and the jaguar to the panther, but that was all. On the other hand, “degeneration” was never a “perfecting.” °° On a deeper level, that of the knowledge of nature, Buffon’s science required a permanent and immutable order, with-

out which man could not know the reality of things, for that reality would be perpetually fleeting and temporary. And it was really in this sense that the notion of genus was indispensable for the naturalist, and that of species for the biologist: it brought order to diversity and permanence to the succession of beings. It founded a science rather than a history.

MORE PRECISELY, the hypothesis of a permanent and immutable order allowed the scientist to arrive at universal laws by way of the history of particular beings. The importance assumed by the history of nature in Buffon’s work as of 1767 is well known.?%” The first two volumes of the Suppleément, the fifth volume containing the Epoques de la nature, and, finally, the Histoire des minéraux present in different forms the elements of a history of the Earth from the formation of the planets until such time when all life will have disappeared from our globe, by then grown cold. In appearance, this history in the Epoques de la nature formally contradicted Buffon’s affirmations in his two vues of 1764 and 1765. Nature existed within time, since it had “epochs.” Juxtaposed to certain earlier assertions — “the great workman of nature is time,” 7°* “nature, I acknowledge, is in a continual movement of change” *°?—this emphasis on the history of nature has greatly contributed to Buffon’s depiction as a precursor of Lamarck’s. In this view, having proposed an immense duration of geological time, explained the adaptation of animals to their climates through climatic influence, affirmed the existence of extinct species (and given the reasons for their extinction),

shown the common blueprint underlying the makeup of animals, and ac-

Buffon 469 cepted the inheritance of acquired characteristics, Buffon must surely have had a historical vision of nature, and must therefore have been a transformist. But no one could understand why his most “historical” work, the Epoques de la nature, continued to affirm the permanence of species and the fixity of the “internal mold.”*”° Hence there is the supposition that Buffon exercised a special “prudence” here—which in light of his character is not implausible,?”! although made moot by a close study of the texts. Conversely, recognition that for Buffon the internal mold was one of the

elements of the eternal order of nature—on an equal footing with universal gravitation, for example—clarifies everything. It is quickly evident, however, that he did not put the two on the same level: gravitation was a “general effect,” whereas internal molds were “particular effects.” Buffon can thus be seen to join hands with the supporters of preexistence, for whom God had created the force of attraction and living mechanisms directly, and so to speak on the same level. Some reconstruction of the general history of living nature as he saw it—although his descriptions are fragmentary, and he perhaps conceived of it only piecemeal —is needed to resolve this final difficulty. At some point in the cooling of the Earth, a temperature was reached suit-

able to the appearance of life—in other words, to the formation of living organic molecules, which had “existed ever since the elements of a gentle heat were able to become incorporated with the substances that constitute organized bodies” *”* These “aqueous, oily, malleable” substances “fell with

water’ at the moment when the earth had cooled down enough to receive them.’’> “As organic molecules are produced only by the action of heat upon ductile matter, 74 it is at last easy to understand Buffon’s 1749 assertion that

“animate life [/e vivant et le animé], rather than consisting of entities on a metaphysical level, is a physical property of matter.” 7”? One had no doubt to accept, however, that at the end of a certain time, the exhaustion of the “duc-

tile matter” and the continual cooling of the earth rendered impossible the formation of new organic molecules, of which since that time there had been only a “determined” quantity. Nonetheless, the existing molecules immediately combined to form animals and plants—not elementary, simple entities, but like those familiar to us, just as perfect and complex. These combinations occurred in all possible fashions: “It seems that everything that can be, is.”?7°

Nonetheless, not everything could be. Certain combinations had succeeded and survived, others had not. Buffon alludes to “the monsters by defect, those imperfect sketches planned and executed a thousand times by nature, which, barely having the faculty of existing, must have continued only

470 THE PHILOSOPHERS SCIENCE for a time,” and then have been erased from the list of beings.?”” No doubt, like Diderot (taking his cue from Lucretius) in the Lettre sur les aveugles,

he was thinking of nonviable teratisms that were no sooner formed than doomed to disappear, or to die without progeny. Thus, the South American sloths were “the last stage of existence in the order of flesh and blood animals; one more defect would have kept them from surviving.” But Buffon was also thinking of the rivalry of species: the sloths had survived only for lack of an enemy.’’* And the worst destroyer was man.’”?

“Everything that can be, is,” and it was futile to seek final causes in the organization of animals. The antlers of the eland or the reindeer, the upper tusks of the babiroussa [a Malaysian pig], were more detrimental than useful to their owners.”*° The order that prevailed in nature was thus an objective order. But it was no less rigorous for that. “In a whole as perfect as an animal’s body,” 7°? the demands of life did not allow for great variations. “The form of all that breathes is more or less the same”; it was “always the same basic organization, the same senses, the same viscera, the same bones, the same flesh,

the same movement in the fluids, the same mechanism and same action in the solids.” 78” In 1766 as in 1753, Buffon emphasized this unity of life, which further narrowed the gap between man and horse, even in the fine points,?*?

and on a more general level gave every living being “the same matrix, the same character, whose principal features are nutrition, development, and reproduction.” 784 All living things resembled one another because, in order to

survive, they had had to accomplish these three functions, without which there would be no life. But they resembled one another or differed from one another according to the extent to which the same conditions had or had not presided over their formation. Here again, the determinism was rigorous: the same climate produced the same animals and the same plants: “Wherever the

temperature is the same, one finds not only the same species of plants, insects, and reptiles without their having been brought there, but also the same species of fish, quadrupeds, and birds without their having traveled there.” 7° In a word, “the same temperature nourishes and produces the same beings everywhere. 78° Thus it was precisely in this that life and living forms, the “internal molds,”

had to be seen as, not merely an episode in the history of the earth, but a phenomenon as general, as universal, and as atemporal as attraction. When Buffon said “everywhere,” he did not mean “everywhere on our planet,” but “everywhere in the universe.” He had calculated when life had appeared or would appear, had disappeared or would disappear, on other planets of the

Buffon 471 solar system, mentioned in the passage from the Supplément just quoted.”*”

The formation of particular “internal molds,” determined by a particular temperature, was an eternal law of nature. Terrestrial animals, and even man

and thought,”** had to be found everywhere in the universe, at least in every , place where the same physico-chemical conditions prevailed and where the same temperature and same ductile matter were found. Like causes produced like effects. The combination of organic molecules produced the same beings under all circumstances. The type of animal, the species in the broad sense of the word, was part of the eternal order and, like it, was immutable. Nature had no history, only individuals did. A sun in the universe of stars, a variety in a species, were simply individuals, variable parts of a permanent whole. Lack-

ing this permanence, science would not be possible and the human mind would exhaust itself vainly attempting to grasp an ever-escaping reality. It still remained to be determined whether this order derived from God.

Leaving aside here the difficult problem of Buffon’s religious beliefs,”®’ it should be noted right away that his conception of science excluded any consideration of a role for the Creator. Limiting himself to the study of nature (1.e., of secondary causes), unmindful of final causes, and even demonstrating at times that all was not perfect in nature, setting forth in possibly intentional disarray the elements of a history of life in which God did not intervene, emphasizing the role of physiological and social factors in the development of human reason, Buffon’s science did without God; it even excluded Him, and would have been perfectly suited to an atheist. Still, God is often mentioned in Buffon’s work. In this regard, a few simple distinctions are in order. In the three volumes published in 1749, God rarely appears and the allusions to Genesis are ironic or at least ambiguous. After 1753 and the discreet protests of the Sorbonne, one senses a greater prudence, a concern for introducing formulas that made what were in fact rather unorthodox ideas theologically acceptable.*?° Nonetheless, certain texts from after 1760 do not seem amenable to explanation by way of the prudential argument. No one asked Buffon to write the “Priére 4 Dieu” that closes “De la nature, premiére vue, *”’ whose more deistic than Christian character could | not, moreover, have pleased the theologians. Neither was it very politic to say, aiming at overly rigorous interpreters of Genesis, that man “prostitutes the idea of the First Being by substituting for it the phantom notion derived from his prejudices.”?°? I believe, therefore, that Buffon was sincere when he wrote in 1774: “The further I have penetrated into the bosom of nature, the more I have admired and deeply respected its Author.”??> At the mo-

472 THE PHILOSOPHERS SCIENCE ment when Buffon began to believe that man could discover the real order of nature, he must have felt the need for recourse to God in order to guarantee that order and man’s power along with it. Thus he was able to write in 1764 what he no doubt could not have written twenty years earlier: “Nature is the throne of Divine magnificence, and the man who contemplates and studies it rises up by degrees to the internal throne of omniscience.”?°4 Up until the Epoques de la nature at least, Buffon had remained faithful to the rationalistic deism that he may have abandoned thereafter, if we are to trust to certain passages from the Minéraux** and the testimony of Hérault de Séchelles.?*° In the last analysis, the question has little importance here. Whether the order of the world derived from God or from the nature of things, it was no less an immutable and universal one. Science needed this order to exist; it did not need to know whence it came.

IV Buffon was a solitary thinker. Not that he was unaware of his age; rather, the philosophic or scientific ideas that he received from his milieu were never accepted passively. They were simply one element in a mind that remained always active, always sustained by the lengthy discovery of nature constituted by the Histoire naturelle, in the course of which Buffon’s special genius became aware of its strengths and its originality. From the start of his work, however, the guiding tendencies of that genius were apparent, and it was evident, too, that they did not correspond very closely with those of his time. From this deep contradiction between Buffon’s intellectual temperament and the ideas that he owed his age stemmed both the originality of his work and the contradictions to be found in it. The originality and contradictions are made unambiguous by his theory of procreation, which, in a mind naturally inclined to philosophic reflection, necessarily led to the problem of the origin of forms, the succession of beings, the order of the world, and the knowledge that man was able to have of it.

_ In 1749, there were two ways of not understanding the universe: God and chance, unknowable order and disorder. Buffon rejected both of them. His character and his philosophical formation, however, drew him towards the atheistic Epicureans far more than towards the pious observers. If he was a mechanist and atomist, an enemy of final causes and preexistence, a supporter of the dual seed and of preformation through the “internal mold,” it was in the manner of the last Epicurean biologists of the seventeenth century.

Buffon 473 He went even farther, but in the direction set by their tradition, by reviving spontaneous generation after his own fashion. That he supplemented their mechanism with Newtonian attraction, and their materialism with Lockean sensationalism, neither added nor changed anything essential. Like them, he did not finally believe in the absolute power of human reason. But his intellectual character, his passion for understanding, his taste for generalization, for the comparison of facts and the search for analogies, and his predilection for order, manifested as clearly in the organization of his life and his work as in his thought, lured him away, so to speak, from the ideas he had received and that he held as true. The power of his own thought kept him from despising human reason. While denying man the power to imagine the “internal mold” or the “penetrating forces,” he described their action. He reduced life to matter, but his theory of organic molecules eliminated practically all possibility of a passage from crude to living matter. He rejected preexistence but

affirmed the fixity of species, and his concept of epigenesis supposed a “devel- , opment” of the germ similar to that imagined by the supporters of preexistence. He kept what was most rigid and geometrical and, so to speak, least biological, in mechanism, and it is not hard to sense that this mechanism gratified his taste for clarity, which was to make him rigorously insensitive to the temptations of vitalism. Over time, these basic features of Buffon’s character became more and more clearly stamped upon his work. Parallel to his investigations into fourfooted animals, he pursued his reflections on the great problems of physics, on light and heat in particular. The result of this effort was to appear only in 1774 and 1775, in the first two volumes of the Supplément. But already in 1765,

with “De la nature, seconde vue,’ he was showing how all the phenomena of both crude and living matter could be reduced to a single force, that of attraction. He had become convinced by then that he had discovered, no longer merely an order relative to man, but the real order of things. In parallel fashion, the animal species, instead of being a unit in a list, became a means of classifying the varieties of living beings. Broadened into genus and family, it was to permit even the classification of what naturalists had always called species. In this way, all the quadrupeds, assembled earlier into two hundred families, were reduced to twenty-five genera and thirteen isolated species — a real order, inscribed in nature, where man had uncovered it; an immutable order, because it was guaranteed by the permanence of the “internal mold”; even an eternal order, since the initial formation of each internal mold had been effected according to universal and eternal laws.

474 THE PHILOSOPHERS SCIENCE Nonetheless, the “degeneration of animals” within species or genera led Buffon to conceive of a history of animal forms. This notion, soon to be extended to the earth and minerals, and which would allow him to write the Epoques de la nature, in no way contradicted the idea of an eternal order for him. Quite the contrary, it allowed him to introduce that order even into the individual variations that might have seemed to lie outside its purview. The degeneration of animals, the formation of the upper layers of the terrestrial globe, and the “génésie [sic] of minerals,” were rectilinear evolutions, in which like causes produced like effects. No catastrophe, no unexpected event could interfere to upset the natural course of things, and the scientist could foresee the future just as he could reconstruct the past. He could establish the time when life would disappear from our frozen earth. But at that point, on other planets, living beings like earthlings, formed according to the same laws, would be experiencing the effects of the same degeneration. Terrestrial man would have disappeared, but thought would live forever. The confrontation between man and nature thus ended with the triumph of man—that is to say, with the triumph of thought, which had discovered the order of the world behind the diversity of beings and the eternity of laws behind ephemeral forms, even in their evolution. In this sense, Buffon had

founded a positive science, and one that in practice did without God. It does not appear, however, that this basic aspect of his work really attracted attention. In 1749, scientists and philosophers were responsive above all to the rejection of the preexistence of germs, to the resurrection of spontaneous generation, to everything that tended to free nature from the ordering power of God and, on the methodological level, to the rehabilitation of hypothesis. Buffon’s great biological discourses and the Epogues de la nature had to await the beginning of the nineteenth century for their importance to be recognized. Then, however, they would be studied in light of the efforts of Lamarck, Cuvier, and Geoffroy Saint-Hilaire: what was sought in them above all was the historian of nature and the precursor of transformism. On one side as on the other, no one was capable of recognizing that the grand object of the Histoire naturelle had been to ground our knowledge of the eternal order reigning in nature in the study of perceptible phenomena.

, TEN Va

Resistance to the New Science

F LYING as it did in the face of official science, and especially of a deeply entrenched mentality, the work of the new scientists and philosophers was bound to raise an outcry. As in the newcomers’ work itself, everything —science, philosophy, religion — was involved in the criticisms with which it met. I shall focus here only on the most important aspects of the general reproval, which also provide the clearest insight into the meaning of the revolution in progress and into the thinking of those who resisted it with all their power.

The biological work of Maupertuis had first appeared anonymously and drew only scant attention from scientists, let alone the public. Vénus physique was seen as a pamphlet of little importance, and Gilles Basset des Roziers’s Anti-Vénus physique, which defended ovism against Maupertuis’s attacks, seems not to have struck much of a note either.’ Despite its promising title, neither can Michel Procope-Couteau’s L’Art de faire des garcons be considered important,’ although it shows that Maupertuis was among the theoreticians of procreation whose names deserve mention and, above all, that the problems studied in Vénus physique were on the agenda of the day, and that the solutions proposed were not such as to frighten a doctor familiar with Hippocrates and the traditional doctrine of dual seeds.’ Procope-Couteau's half-praise was not, however, a sufficient recommendation in the eyes of the

scientific community. , Even Maupertuis’s “Essai de cosmologie” “created no stir in Paris,” if we are to believe the abbé Guillaume-Thomas Raynal, who specifies of the proofs of the existence of God: “Some have felt that M. de Maupertuis had more talent for dismantling than for constructing.” * This comment might,

476 THE PHILOSOPHERS SCIENCE of course, indicate some approval. Not until Maupertuis’s ideas were taken up and discussed by Buffon and Diderot, however, would his contemporaries discern their importance. It was from Diderot’s account in the Jnterprétation de la nature that the Correspondance littéraire in 1754 discovered the “very subtle metaphysics” of Dr. Baumann, the first seeds of which it would also find in Buffon’s Histoire naturelle’ It was in connection with Buffon that Albrecht von Haller, Charles Bonnet, and several journalists alluded to the Vénus physique. As for Voltaire, everyone knows how relentlessly he ridiculed Maupertuis— after having heaped praise upon him—once the Berlin quarrel had estranged the two men for good. But they had already been separated by their ideas, and Voltaire had little trouble in placing his adversary side by side with Buffon, Needham, and “the consul Maillet.” If La Mettrie created a scandal, it was above all because of his materialism

and amoralism. His principal rebutters, Balthazar-Ludwig Tralles, Gottfried Ploucquet, and Haller, paid little attention to his scientific ideas.° Haller, the best qualified in this regard, accused La Mettrie primarily of having plagiarized from Boerhaave and himself,’ and of having resuscitated Lucretius’s ideas, augmenting them with “a few modern-day remarks and discoveries.” He accordingly sent him to consult the Avti-Lucréce of the “learned Cardinal de Polignac.”* Finally, he abjured discussion: “It would perhaps be foolishness to look for something serious and well-grounded in the entertainment of a mere wag.”” La Mettrie’s extravagancies thus gave most of his contemporaries leave not to take seriously his most significantly daring ideas. As one might imagine, the fantasms of Maillet’s Zeliamed were not destined for any greater success. The Mémoires de Trévoux admired its method ironically: “This work is more filled with facts than with arguments, and the arguments are always grounded in the facts.” But what weight did the facts carry? The story of the sailor who emerged from the waves only to plunge back in after having smoked a pipe did not inspire trust: “Can one be blamed for remaining somewhat incredulous concerning facts of these sorts?” '° In brief, it was a “system even more ridiculous and incomprehensible than dangerous.” ! What was serious in the geological comments was eclipsed by the theory of marine animals. Further along, the reviewer saw fit to connect Buffon and his “Théorie de la terre” with Maillet. The abbé de Lignac and Voltaire took pleasure in lumping the two together, when the Mémoires de Trévoux, Pierre Clément’s Nouvelles littéraires, and even the Jesuit turned journalist Elie-Catherine Fréron took care to distinguish between them.” It was thus the publication of the first three volumes of the Histoire natu-

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relle that revealed the intentions of the new science to the public and the scientific community. Its well-known success with the public was immediate and considerable, but the scientists were more cautious. The journalists were deeply divided. The abbé Raynal’s long review was rather nasty: since “the Histoire naturelle is enjoying only a modest success among the learned,” whereas “the ladies, on the contrary, esteem it highly,”’® one must obviously side with the “learned,” which Raynal accomplished easily with a few contradictory rebukes to the author: “M. de Buffon sees the facts very clearly, and metaphysical matters rather poorly.” 4 “The author has not thought it proper to pitch his erudition, or even his style, to the broader readership. He is ever fearful of not being able to support what he says with enough knowledge and facts.” ° In short, Buffon was too much the scientist, providing too many facts and not enough ideas: he was lacking in “the authentic theoretical spirit that permits generalization of facts and the formation of an uninterrupted

chain of consequences.” How are we to reconcile this with the criticism of the scientists, who found Buffon “too quick to adopt systems?” '” Raynal was clearly biased, although he agreed that the work was “deep.” * The praise afforded by the Jesuits was oddly contrary to Raynal’s reservations. The Mémotres de Trévoux even approved of Buffon not wishing to have recourse to God as a physical cause and obligingly proposed a few ways for reconciling the “Théorie de la terre” with Genesis, additionally congratulating the author on having clearly distinguished his hypothesis from the factual physical history.’? The theory of procreation was “treated with a clarity, a breadth, and a competence that leave nothing to be desired.” ?° Buffon’s Histoire naturelle de '-homme demonstrated the author’s spirituality.2? Louis Daubenton was accorded the same benevolence.”* Only in 1753, with the reviews of the fourth volume of the Histoire naturelle, would certain reservations appear regarding both religion and science.” After the Lettres 4 un Amériquain, the Sorbonne’s censure, and Haller’s comments, the Jesuits may have feared to find themselves isolated with respect to both Catholic and scientific opinion by continuing to praise so criticized a work. After the long resumé of volume 1 of the Histoire naturelle published in the Journal des Savants—a very flattering resumé of “a work so well fitted to bring honor to our age and our nation,” ** but that oddly enough was to be followed by a silence of over two years ”* — it was Fréron’s turn to sing Buffon's

praises.2° His resumés were exact and intelligent, and his enthusiasm would hold firm in 1753, despite problems with the Sorbonne, of which he said not a word, ending his review that year by asserting: “What is most sublime in

478 THE PHILOSOPHERS SCIENCE philosophy, most interesting in physics, most noble in eloquence, and most brilliant in poetry are assembled in [Buffon’s and Daubenton’s] Histoire natu} relle.””*” (The little liking for Buffon evidenced by certain encyclopedists— such as d'Alembert — may have played a role in this kindness on Fréron’s part.) As for the Jansenists, they wasted no time on balanced judgment. As early as February 6, 1750, Nouvelles ecclésiastiques had exposed “the venom” contained in the Histoire naturelle, devoting practically the entire issue to it, along with

two pages in the following issue. Buffon made an animal of man, was “an utter Pyrrhonist,” contradicted Genesis, and thought that the world was eternal. If he was the Christian he claimed to be, let him follow Job’s example and say: “I disavow my conduct and repent, covering myself with ashes and dust.” Otherwise, let the blade of authority descend upon “so pernicious a book,” upon the entire Académie des sciences, upon the author of the laudatory review published in the Journal des Savants, and, while it was at it, upon the Académie des inscriptions, which had sponsored Pope’s Essay on Man, as well as on the Académie francaise, which had had it translated, and even welcomed Voltaire into its midst.28 The hatred here borders on delirium, and the abbé de Lignac was by comparison to seem filled with good sense and courtesy. The reviewer, nonetheless, displayed a certain clairvoyance: the science he was defending, which accepted Revelation and tried to use the Flood in order to explain shell fossils, had no greater enemy than Buffon. Set next to these anathemas, Clément’s remarks seem a bit pale, since he was favorable to the theory of procreation and merely noted in Buffon’s disfavor that he was “accused of being more a metaphysician than an observer,” *? which was the exact contrary of what Raynal had said.

ONE MAY ASSERT along with Friedrich Melchior von Grimm, then, | that the first three volumes of the Histoire naturelle “were received to universal applause,” while considering the “inconsequential pamphlets that intrigue and envy forged against this immortal work” to be the inevitable ransom of success.°° Aside from the surly abbé Raynal and the fanatical Nouvelles eccleésiastiques, all of the reviewers had been favorable. None, however, not even

the Jesuits, had entered into a genuine discussion. They had admired the style, more or less accepted the theories, and passed more or less favorable _ judgment on the author's religious positions. But it all remained superficial. Serious polemics were to begin only with the publication of the first books devoted to an examination of the Histoire naturelle.

Chrétien-Guillaume de Lamoignon de Malesherbes’s Observations sur

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l’Histoire naturelle was the first such work. The young magistrate no doubt composed it very soon after the publication of Buffon’s three volumes but, having himself become an honorary member of the Académie des sciences, decided not to publish it out of courtesy and friendship for a colleague whom he esteemed.?! Malesherbes, who was passionately interested in botany and very well informed on the problems of classification, had no difficulty in showing that Buffon had not understood the intentions of the classifiers. Above all, however, he rebelled at the idea of a chain of beings whose imperceptible shadings prevented any clear distinction. These shadings risked destroying the very notion of species. For species did in fact exist, they were immutable, notwithstanding that there might be varieties within them, and they were grouped into natural families that a natural method had to be able to recognize.?” What Malesherbes especially rejected was the idea of disorder in nature. For he saw in this the source of another error, that of considering the naturalist merely as a mindless pieceworker, and people like [Konrad von] Gessner, [Pierre] Belon, and [Joseph Pitton de] Tournefort merely as subaltern philosophers endowed by nature with a degree of mental strength and activity sufficient to endure a great expense of energy, but whose entire merit consists in these natural endowments, along with, at best, a fortunate memory; so that if their observations can ever be useful, they will bear fruit only in the hands of some higher genius, some profound metaphysician, who, without leaving his cabinet, will perceive at a single glance the hidden relations that have eluded the limited intelligence of the observers, will teach them what they should have known, and will make them aware of the worth of their discoveries.?4

Psychologically, the observation is keen and hardly a caricature. Nonetheless, it is interesting to see Malesherbes bringing in Gessner, Belon, and Tournefort, who were naturalists of the sixteenth and seventeenth centuries, not his contemporaries. He was a rationalist in his own fashion, which was that of Tournefort. The order that the naturalist discovered in nature was for him obviously the order of nature itself. He thus understood nothing of Buffon’s reflections on the relative character of the notion of truth: “The truth is entirely independent of us,” he wrote; “it is anterior to all our knowledge.” Mathematical truths did not depend upon the human mind: the relationship between the volume of a hemisphere and that of a cylinder had existed before Archimedes demonstrated it.34 The difference Buffon asserted between mathematical truths, based upon definitions established by man, and physical truths, imposed by the facts of nature, was accordingly unintelligible.» Moreover, Malesherbes understood neither Buffon’s thinking nor the role

480 THE PHILOSOPHERS SCIENCE it assigned to metaphysics: “I believe . . . that M. de Buffon fell into most of the mistakes I have noted only because he abused the metaphysics for which he has such high regard, and because he felt that with its help he could dispense with learning the facts that are the groundwork for most sciences.” *° Buffon had never believed any such thing; he had even specifically stated

the contrary. But Malesherbes never thought of designating a theory of knowledge by the word metaphysics, which he discussed at length. He either gave it the Scholastic sense of a “psychology” and an ontology on which the sciences had no bearing,’ or, in the sciences, saw it as the abstract as opposed

to the concrete. Thus, rational mechanics would be the “metaphysics” of a , large part of physics; geometry would be the “metaphysics” of rational mechanics; algebra, finally, would be the “metaphysics” of geometry and perhaps of all the other sciences.** So conceived, metaphysics in the sciences became nothing more than a mental cast, a tendency to see things from above, and to scorn observers and “detail people.” In fact, it was an abuse “typical of our age, an age marked by self-satisfaction and frivolity.” *? This juvenile harshness of judgment— Malesherbes was not quite 30 — joined with basic incomprehension, explains his global condemnation of the “Discours de la maniére d’étudier et de traiter | Histoire naturelle” as “virtually from one end to the other a fabric of errors.” *°

The critique of cosmogony is only of secondary interest to us here. Malesherbes reproached Buffon for having dealt with a question that did not belong to the natural sciences, and for having presented a somewhat unoriginal

solution, a judgment that might be contested. But he also reproached him with not having explained the movement of the Earth, because he had not first of all explained the movement of a comet that was supposed to have collided with the Sun: “When one wishes to give the cause of a body’s property,” he wrote, “one is not presenting a plausible hypothesis by assuming

that this property has been imparted to it by another body, if one does not know the cause of that property in the other body.” *! Malesherbes did not understand that Buffon was attempting to imagine a cause common to the movement of the planets because he possessed facts allowing him to imagine such a cause, whereas, precisely for lack of facts, he could not imagine the cause of the movement of comets. Instinctively, Malesherbes was expecting

a total explanation of the world, a system in the Cartesian manner. Nonetheless, in a highly revealing contradiction, he immediately went on to assert that one could not draw any conclusion from the fact that the planets moved in the same direction and almost in the same plane, that “a thousand events

Resistance to the New Science 481

that we cannot imagine” might have occurred within the solar system, and that it was perhaps better in the long run to have recourse to the direct action of the Creator, “which would be more literally in agreement with the text of Genesis.” 42 Malesherbes wanted everything explained, even at the cost of immediately labeling everything inexplicable. Regarding generation, Malesherbes reproached Buffon with a general abuse of “metaphysics” (i.e., of abstract reasoning), picked up the ill-conceived image of the “internal mold,” denounced all those unexplained “powers’ lent to living nature, and considered the organic molecules an ingenious hypothesis as impossible to prove as to demolish. Still, he appears to have accepted almost all of Buffon’s criticisms of ovism and animalculism, which is rather remarkable. Needham even came in for praise, no doubt because he was an “observer.” In all these pages, the criticism is surprisingly moderate: Malesherbes did not feel himself to be on familiar ground, and, if he remained skeptical, he hesitated to condemn. Of particular interest in the Observations sur l'Histoire naturelle is the sense

it conveys, in both praise and blame, of complete freedom and perfect honesty. Malesherbes was particularly well informed about problems in botany, and as was natural, he was especially severe with respect to classification, where

he felt capable of judging. Like most scientists, he was filled with mistrust of “metaphysics,” in which he saw only an abuse of abstraction and a temptation to laziness. At the same time, he unconsciously practiced an unformulated and contradictory metaphysics. He set down as principles the rationality of

the world and the primacy of observation without bothering to ask himself how science was to pass from one to the other, how human observation was to attain the divine order. As a botanist more familiar with Tournefort and Linnaeus than with modern observers of insects, he was closer to Fontenelle or Malebranche in his implicit rationalism than to Réaumur, whom he hardly mentions. Nonetheless, faced with an intellect striving to reconstruct the past with the aid of known facts, he grew uneasy and uncomprehending, preferring to imagine inconceivable events or God’s intervention, both of which interdicted the exercise of reason. Malesherbes was unable to understand Buffon’s thinking because the problems it raised seemed to him foreign to science, and because Buffon’s answers contradicted his underlying convictions. Many other scientists were to find themselves in the same situation and were able to echo Malesherbes’s formulation: “We do not deny that the author is a man of great intelligence. . .. We simply deny that he is a natural-

ist, and consequently that he is competent to speak pertinently about natural |

482 THE PHILOSOPHERS SCIENCE history.” 4 Finally, independently of any question of science or philosophy, Malesherbes’s irritation at Buffon’s decisive and dogmatic tone foreshadows the exasperation of scientists less inclined to courtesy than a young magistrate without academic ambitions.

IT WAS NOT AMBITION, however, that impelled the abbé JosephAdrien Lelarge de Lignac to write his Lettres a un Amériquain, the most violent attack on Buffon, whose publication began in 1751. Born in Poitiers around 1710, a former superior of the Oratorian monastery in Nantes, de Lignac had just left the Oratorian order in 1750 and had settled in Saumur. In 1743, he had published a Jansenist pamphlet,** then in 1748 a little Mémoire pour servir a commencer Ll histoire des araignées aquatiques. At least as early as 1749, he had become a close friend of Réaumur’s and his companion at table

during the vacations that the scientist went to spend in Poitou every year from the beginning of September until All Saints’ Day [November 1]. One may therefore assume that the initial idea for the Lettres was born during the vacation period in 1749 when Réaumur and de Lignac were performing observations together on Irembley’s polyp.* The idea had to be tempting to Réaumur. His hostility to Buffon dated from at least 1740 and rested first of all on a personal antipathy.*° Even before the publication of the Histoire naturelle, Réaumur had been talking about it with reservations filled with disobliging implications.4” No sooner had the three volumes appeared than he went on the attack. It was a “senseless” production,*® the volumes “could only harm the progress of natural history and of physics in general, if the propositions advanced in it were adopted,” 4? and Buffon’s work decidedly deserved a harsh response. When the Lettres began to appear, Réaumur recommended them warmly to his correspondents as a “critique . . . as pleasurable as it is solid,’ °° “a solid and ingenious critique,” *! “a critique . . . to which no effective rejoinder can be made,” *? and whose author was “a solid reasoner, great metaphysician, student of natural history, geometry, etc.,” °° “a charming man and an excellent mind.” * In short, Réaumur assuredly gave the work his patronage and all possible publicity.* It is not certain, however, that he collaborated on the first three volumes, published in June 1751. It was only during the vacation of that same year, in the months of September and October, that Réaumur was to undertake to reproduce the microscopical observations of Buffon and Needham, in company with the young naturalist Mathurin-Jacques Brisson, who served as technician — Réaumur was not very familiar with the microscope—and de Lignac. “I have left to Father de Lig-

Resistance to the New Science 483

nac the responsibility for putting his observations in order and making them public,” wrote Réaumur.** This, however, applies only to the two volumes of the Lettres that appeared in April 1752.°” The first three volumes may have benefited from the “technical collaboration” of Pierre Bouguer.’* Réaumur certainly approved the writing of them. But it is likely that he did not directly collaborate in it.

And one might be happy to think so for the honor of Réaumur, who was capable of ferocity towards those who did not think like him,? but whom one cannot imagine being so meanly sly. It is moreover worthy of note that the Lettres a un Amériquain, intended as a defense of religious and scientific orthodoxy, appeared anonymously and with a false place of publication, both precautions worthy of an impious work.®° We have to assume that Buffon was already a power to be reckoned with, and that it was somewhat risky to attack him. Be that as it may, de Lignac’s basic aim was to demonstrate that Buffon's

work was utterly anti-Christian, in which he was entirely right, considering his notion of Christianity and of Christian science. But everything was in the way things were expressed. Buffon “now professes to recognize the divinity of the Mosaic books.” We should therefore have to take him at his word. How-

ever, ‘the materialists regard his enormous preface as the anti-Polignac and as the restoration of Epicureanism.” And they were quite justified in so thinking: “In his work, all occurs by chance.” Without speaking of maxims dangerous to morality or of descriptions that offended modesty, the principles of [Buffon’s] metaphysics were “such as the Pyrrhonists would present if they were allowed to have principles.” First Cause was “set aside” and the Bible was contradicted: “According to the sacred text, the Earth was created and cloaked with grass, and the Moon was formed at the same time as the day star [lastre du jour—i.e., the Sun]. According to M. de Buffon, the Sun is the first in date. .. . How could one go about contradicting more openly the history of Creation?” If we were to follow Buffon, “we would spare God the trouble of creating the animals, but we would fly straight in the face of the letter of

the sacred text.” °' “After all this, I do not imagine one will be surprised that the materialists claim to have certain rights over the new natural history.” ° “Whereas other authors know how to raise us up to the Creator while entertaining us with the history of an insect, M. de Buffon hardly allows us to see Him while explaining the construction of the universe.” © The “other authors” have been able to manifest their disapproval. The tactfulness of the Académie des sciences, and its proper attention not to involve itself in anything that could offend religion, is fully justified by this very book: the

484 THE PHILOSOPHERS SCIENCE author is of the Académie, but the frontispiece does not declare it; this is proof positive either that he did not dare to communicate his work to the Académie or that, if he did present it, he was not able to obtain its approval.®4

One still could but wonder at the strange blindness of a man who called himself a Christian but who was so little such. “It is not too easy to give you a definitive answer on this point.” All one could say was that Buffon was not constrained by the force of his proofs, “for what kind of proofs can one reasonably set against the revelation of which God Himself is the author?” © And so? Must we then (oh, horror!) harbor suspicions concerning Buffon’s good faith? Or rather, would the true explanation not be the following, which the abbé de Lignac suggested without naming names: It is not the true scientists whom I suspect of incredulity, it is those vain men, those half-scientists, it is they alone that one must accuse of hindering the progress of the sciences and hastening their destruction; they have no other goal but to dry up all the springs of science, because they understand very well that these are so many ways to Christianity.°¢

One can now understand the full meaning of one of the earliest statements in the work: Buffon “loudly professes to recognize the divinity of the Mosaic books. But it is undeniable that he openly works to destroy all the principles of the sciences.” °” Buffon was merely a “half-scientist,” more concerned with destroying faith than with advancing science. Possibly de Lignac’s bad faith was merely the counterpart to Buffon’s precautions. But Buffon had not been attacking anyone, and he had no choice in his means. Moreover, and whatever the tone, the abbe’s attitude is clear. The true goal of science was to lead to God, and even the history of an insect was a mere entertainment. De Lignac did not wonder if the God in question

was that of the Christians or that of the deists: the problem did not arise, since science could not deviate from the letter of Scripture. Accordingly, de Liganc cannot be expected to have understood Buffon, and one should not be surprised to find him ironically admiring the “modest reserve” that had kept Buffon from explaining the formation of the stars through an encounter with a comet.®® When he finally got around to examining the “metaphysics”. of the Histoire naturelle, de Lignac accuses it, of course, of falling “into the most indefensible Pyrrhonism” and at the same time of going beyond the boundaries of “human pride” in saying that the sciences were “precise and demonstrative” because they came from us. “The truth, then, would be the

work of man! Who does not believe, on the contrary, that mathematical truths are demonstrative because they flow from a source that is very much

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above us?” Buffon was a disciple of Locke, the philosopher who had “thrown metaphysics into a confusion far more dangerous than the vain imaginings of Father Malebranche.”°? Between the idealistic rationalism of de Lignac and Buffon, who was attempting to found a “positive” rationalism, there was no possible dialogue. And all the less so in that de Lignac excelled in the art of diverting the discussion and splitting hairs over imaginary difficulties. Let one example suffice. “I shall concede, if you will, to the divine Plato and to the nearly divine Malebranche, for Plato would have regarded him as his simulacrum in philosophy... ,” Buffon had written,”° and de Lignac commented:

“He thinks that Plato would have scorned Father Malebranche. On what does he base this conjecture?” There follow two pages of discussion, with a eulogy of Malebranche, whom Buffon scorned because he had not read or had not understood him.”* With methods such as this, it was easy to write five volumes without saying much. Regarding natural history, Lignac rejected the idea of imperceptible gradations between beings and kingdoms. Polyps were animals—indeed, “the most industrious of known animals.” Unfortunately, the only serious argument advanced against the chain of beings was that “the materialists abuse it.” For “the materialists, those half-scientists, the shame of our century, would have one understand that all these diverse preparations of nature can end up creating an intelligent and free machine.” ’* De Lignac was no doubt thinking of La Mettrie. He was far less at ease than Malesherbes on the subject of classification and seems to have been unfamiliar with its problems. Buffon’s classification aroused his irony: if one classed beings according to their proximity to man, should one not begin with the flea?’* The satire was clever, although a bit long-winded. One might reproach him with literalism, which had already been his method with Buffon’s theory of generation: not only did de Lignac pretend to believe “that each part that enters into the composition of a horse, or a man, was a little horse or a little man”—and then, © how could we “for example, construct the eye of a full-sized horse with imperceptible little horses?” ’4— he also conceived of the “internal mold” as a “knitted sock,” whose “thread is hollow, and matter has been injected into it which then congealed.” Clearly, one could not remove the new sock thus created without breaking the mold.”* The theory of generation was certainly sufficiently vulnerable not to require this kind of criticism. Finally, moreover, de Lignac thought that Buffon had “by chance wed two words implying a contradiction” and that the internal mold simply revived the plastic forms of the Peripatetics.’”° As for organic molecules, de Lignac wondered how those

486 THE PHILOSOPHERS SCIENCE eternal corpuscles had “been able to boil for millions of centuries in the molten matter of the Sun without being transformed in the process.”’” The ambiguities in Buffon’s thought of 1749 might indeed justify the question.

The three 1751 volumes of Lettres 4 un Amériquain had, then, successively examined the cosmogony and the theory of the Earth, the reproductive theory and natural history of man—here, Buffon was deemed a materialist because he denied animals souls and granted them bodily sensations ’* —and finally the “Discours sur la maniére d’étudier et de traiter histoire naturelle.”

, The two 1752 volumes dealt with Buffon’s collaborators and visibly bear the stamp of Réaumur, who is mentioned with great frequency and is the object of weighty eulogies. Accounts were quickly settled with Daubenton: a mediocre mind, indentured to Buffon, and quite incapable of classifying the collections at the Cabinet du Roi. He really should have gotten his inspiration from the magnificent cabinets of M. de Réaumur! There, he would have found the solution to all the problems that had stumped him. Moreover, the man was not very scrupulous.”? He was granted only one merit: having praised Réaumur.*°

Needham’s turn came next, and this was where Réaumur intervened. He had been associated with Needham, had taken the trouble to help in the distribution of the latter’s Nouvelles observations microscopiques,* had enjoyed his company,°* and had even praised his work and his gifts as an observer, writ-

ing to Trembley: “M. Needham .. . has a mind and eyes that will not miss facts worthy of notice when they happen to present themselves to him.” *? In 1751, Needham had fallen under the sway of Buffon; still, before criticizing

his observations, Réaumur had felt obliged to reproduce them. Only then was he able to inform Charles Bonnet and Trembley that the observations had been “badly done and often false,” and that in duplicating them he had even “seen at times what had fooled them [Buffon and Needham] when they were attempting to adjust their observations to fit their theory.” ** De Lignac was not, however, able to profit from these verifications. Before getting down to the facts, his eleventh letter emphasized Needham’s obscurity, the aid he had given the materialists, the anteriority of theory with respect to experiment, the rejection of preexistent germs, and the resurrection of plastic forms. At last, the subject of the experiment on infusions of almond kernels was broached. After a protracted discussion on the “spontaneity” of the movement of their particles,®° de Lignac went to the nub of the matter: according to Needham, this movement could not be attributed to the presence of microscopic creatures, since the steepings had been isolated in a stoppered

Resistance to the New Science 487

flask. “I draw the author’s attention to this last conclusion. How could one have been sure that there were no creatures in the air contained in the bottles, or in the almond seeds?” *” This is the most discerning comment in the entire work. De Lignac repeated it in greater detail with respect to the experiment on the juice from roast meat: The tiny animals, or their eggs, could have stayed attached to the sides of the glass, or been caught up in the juice in settling out of the air. We do not know what degree of heat the airborne creatures can withstand; we are unaware whether their eggs, in order to hatch, do not need a heat very much above that which causes our familiar fowls’ eggs to hatch.®8

The debate opened here was to last until Pasteur. De Lignac’s criticism exactly shows the defect in Needham’s experiments. There was no point, after that, in asking whether some ill-motivated person might not by chance have

“cleverly made an addition, by unstopping the bottles unbeknownst to the author.” 8? Above all, however, it would have been better to abstain from all

attempts at a theoretical explanation of the facts, and not to imagine “that some swarm of animals, imperceptible even to the eye aided by the microscope, had gotten into this particle [of almond kernel], and had made of it a sort of lodge, or sort of boat, in which it perhaps would find, along with all it needed for subsistence, the ease and pleasure of sailing about in the water. °° Charmed by this hypothesis, de Lignac developed it with respect to the almond infusion,”’ returned to it with respect to spermatozoa (they, too, produced by swarms of airborne animals),”* and at still greater length with respect to the growths [végétations] on degermed wheat grains.?* At least this _ theory was intelligible, whereas Needham’s was not.?* And de Lignac arrived at this astonishing admission: “Finally, Sir, there is no physical hypothesis on which I would not have drawn, rather than use metaphysical explanations, which would surely not have taught me anything and boil down to the following: that there lies behind these molds a reproductive cause that I do not know.” ”? Imagining invisible “swarms” was a “physical hypothesis”; imagining a “force” was metaphysics, and a metaphysics that the abbé de Lignac wanted absolutely no part of. What is most remarkable in all this is that de Lignac debated Needham’s conclusions, not his observations themselves. Had

he reproduced them? He explained uncomfortably with respect to the infusion of almond kernel: I performed this experiment, and in comparing the results of my observations with M. Needham’s account, I do not find them in agreement with his. I even have reason to presume that certain conditions working in favor of the theory of the two friends

488 THE PHILOSOPHERS SCIENCE [Buffon and Needham], and which for this reason they may have adopted without close examination, may have deceived them; but I shall save this detail for next summer, when I intend to repeat M. Needham’s experiments by following faithfully what little he has told us of them; for he seems to have wished to preserve secrecy on the details; one nearly always has to guess at his meaning; I shall give you an account of the outcomes of my work at the proper time.?°

This passage raises problems. If it was written on November I5, 1750, as de Lignac avers,’’ it was prior to Réaumur’s experiments. In that case, it is understandable that the criticism was directed at the conclusions and not the

facts, but not that the abbé de Lignac should have stopped there and should never have presented the account of his “outcomes,” since the text in question appeared in April 1752. If the date presented is fictive, and if this eleventh letter was written between December 1751 and April 1752, it is astonishing

not to find here the specific results of Réaumur’s experiments, as Réaumur had himself announced them to Trembley and Bonnet.?® Since one is reluctant to believe that Réaumur attempted to hoodwink his friends concerning the outcome of his verification, the mystery remains unresolved. Examining Needham’s metaphysics in the twelfth letter, de Lignac aimed above all at demonstrating its “inaccessible obscurity.” He summarized it more or less successfully, without understanding it, but without deliberate distortion. Overall, in any case, Needham was treated better than Buffon. He was even awarded the merit of knowing how to “think up rather delicate experiments, of-surely displaying “inventiveness” in this area, even of “taste” and “sagacity.””? After all, the abbé Needham was a colleague, his religious attitudes were beyond suspicion, and he had displayed a gift for observation.'°° ‘Too bad he was not a better metaphysician! The Suite des lettres a un Amériquain that the tireless de Lignac published in 1756 was, moreover, even more moderate in tone. Specially devoted to the problem of the souls of animals, and directed as much against Condillac as against Buffon, this sequel examined other subjects in passing: defense of the notion of species and of systematizers,’*' and a long attack on organic molecules, which although invisible were supposedly learned enough to create an embryo (Buffon had said no such thing), garnished with a lengthy defense of preexistent germs, which had the great merit of explaining everything, even partial regenerations.'°* Here again, de Lignac let fall a significant word:

, “The mechanics provide enlightenment that instructs and reassures us about this odd fact regarding worms cut in pieces.” °? Without mechanism, there would be nothing but a frightening mass of spontaneously active matter. It

Resistance to the New Science 489

was more comforting to seek the visible intentions of Providence in nature. To wish, like Buffon, to set aside final causes, was to wish to bring chaos back into physics, to banish “the most significant part of philosophy,” and to believe that nature was “mad or blind.” !°* De Lignac noted, however, that Buffon had since corrected himself and was less caught up in metaphysics. Indeed, de Lignac, too, had had to change his tone somewhat, and although probably under no illusions about his adversary’s religious attitudes, he must have resigned himself to greater discretion on the subject. The reason was that the Lettres of 1751-52 had received a lukewarm reception. Nouvelles eccléstastiques, proud of having been first to denounce Buffon’s

irreligion,'”? had openly applauded “an author who in truth seems infinitely better informed on the matters he is dealing with than the supposed scientist whom he has a talent for refuting with as much politeness as force.” 1° (Where politeness was concerned, of course, Nouvelles ecclésiastiques’s stamp of approval was not overly reliable.) Elsewhere, too, de Lignac’s book was praised especially for its scientific value. “The critic does not enjoy the stature of the author whom he is attacking; but he is precise, clear, and learned, and possesses much sagacity, Raynal declared. “This work is creating a considerable stir, and has a very large number of supporters. You will see in it, of course, that M. de Buffon is usually wrong, and that if one took away his style and manner, not much would remain.” '°” Pierre Clément knew that this “very fine book” was actually the work of three authors— Bouguer, Réaumur, and de Lignac—and he regretted that they seemed “so often to be right.” 1° The public had surely not been sorry to see criticism of a work whose dogmatism had hoodwinked it. To censure “Buffon on many points, errors, and contradictions emanating from the vanity of a prideful and superficial author,” as René-Louis d’Argenson said, was to assure oneself of “not a little success in the public.” The tone of the Lettres was less successful, however, and distasteful rumors made the rounds. “The true author [was] M. de Réaumur, of the same Aca-

démie des sciences as M. de Buffon, a great enemy of the latter, envious

and jealous of his works and recognitions,’ d’Argenson reported. Réaumur , had simply got himself “an assistant, a minor Oratorian father who [had] composed the work [and] avoided making it entirely a matter of piety and of religion avenged.” '°? Still more clearly, Pierre Clément accused the “tri- _ umvirate” of having “at times distorted the ideas, misused M. de Buffon’s terms, and imputed consequences to him that he had never thought of; and of having sworn that there was nothing good in the book except the style.”

490 THE PHILOSOPHERS SCIENCE “Simply read the opening letter,” he added, “and you will see the z//-will, the odium theologicum, and everything implied therein.” And he denounced “the false, awkward, and wretched impression” the authors gave of the famous passage in which Buffon imagined the awakening of man to nature, exclaiming: “Three philosophers’ heads in a doctor’s bonnet! A physicist is not allowed the most innocent supposition. What is required of him is an endless moral commentary on Genesis!” "° Finally, the most lively attack appeared in 1753 from the pen of André-Frangois Boureau-Deslandes: Where do these ridiculous inventions come from; whence this disguise that fools no one; whence this imposture in the title and in the personalities? They should openly, but politely, have stated their intention, without casting aspersions on the religious attitudes of someone whose conduct breathes only honor, virtue, and probity. This accusation keeps returning, and is none the less odious for it.’

It is understandable that de Lignac, faced with “all these outcries” — the words are his—should have considered it useful to change his tone in 1756. He even attempted to justify himself, defended himself against the charge of having “lent himself to the passion of a scientist with whom [he was honored] to have had very close ties,” and sloughed off onto the printer the responsibility for the false address."'* His “general reply” is quite surprising: The supporters of M. de Buffon have appeared to be more sensitive and offended than himself: he was not at all wounded by the contradictions that I found in the different theories, by the lack of logic I reproached him with so manya time, nor by the _ mistakes in which I caught him .. . : any other less tranquil philosopher would not have forgiven me for having been right in his regard: he admits he is wrong on all these

points, or at least his stubborn silence indicates that he is not offended by them.'?

De Lignac was right, then, because Buffon had not responded. But Buffon on principle never replied to critics. In 1750, he had already heard “some yappings on the part of some people [whom he had] felt it proper to disdain.” !4 Following the first Lettres 4 un Amériguain, he contented himself with writing to a friend: “You must have heard talk of a very lively criticism of the first volumes of my Histoire naturelle, a criticism that I attribute to the Oratorians, abetted by a pedant from the Academy, and that I have no intention of answering, because it has not affected me, and because, moreover, I am far more indifferent than is assumed to the success of my opinions.” *? This indifference was not an act. It was grounded in the immense self-confidence of a man who was not afraid to say: “Everyone has his special point of vanity, and mine is such as to believe that certain people cannot even offend me.” 1° This lengthy— perhaps too lengthy—discussion of the Lettres a un Ameé-

Resistance to the New Science 491

riquain is necessary in order to destroy a legend. De Lignac did not embody “true science” in opposition to Buffon’s “theories,” as two isolated quotations from the eleventh letter would have one think. The primary intention of his book was not scientific but religious. He was defending a science and philosophy that he judged alone to be compatible with Christianity. The science he was defending limited itself to admiring observation of the wonders of Creation, stayed scrupulously within the bounds of the most literal interpretation of Genesis, and saw in mechanism the surest proof of the existence of God. For de Lignac, fossil shells bore witness to the Flood; all generation or regeneration presumed preexistent germs; the search for final causes was “the most meaningful part of philosophy,” because it provided science with its edifying power; and spontaneous generation was impossible, because it would impair the rights of the Creator. The only aim of these Lettres was to destroy the scientific bases of an irreligious philosophy, or one that risked becoming such. For de Lignac, as soon as nature was given the slightest autonomy, as soon as it was no longer a passive mechanism in the hands of God, religion was in danger. Buffon’s daring gave him an easy target, and it was natural that he should have taken advantage of it. Still, on Needham’s experiments, one of the points where he should have triumphed, and where some have wanted to see him as a precursor, we have found him strangely timid, multiplying hypotheses in order to explain according to his intentions facts that he did not dare to contest. He himself had to agree that this part of his work “had made slight impression; that it had left readers more than indifferent.” "” The malice of the Parisian public found amusement in seeing Buffon and his dogmatic bombast mortified, but it cared little about Needham and spontaneous generation. However, the frankness of such an admission leaves the reader perplexed. Perhaps, after all, de Lignac was an honorable man when acting on his own and when the interests of religion were not at issue; that is, those interests that he no doubt felt himself justified in defending with whatever means. And it is true that the intellectual universe in which he lived fairly well prevented him from understanding the true meaning of Buffon’s work. At least, however, he might have avoided sterile discussions of imaginary difficulties and made an honest effort to go beyond the words to the ideas he was combating. Lacking this honesty, this elementary form of integrity, de Lignac was unable to be more than a mediocre pamphleteer, more clever than convincing, and a poor defender in the last analysis of a science and a philosophy that deserved better.'"®

What of Réaumur’s attitude? Nothing proves that he was the instigator of

492 THE PHILOSOPHERS SCIENCE the Lettres a un Amériquain. In fact, it seems that for obscure reasons, his real collaboration was slight. He nonetheless cloaked the work in his authority

and surely approved of it with all his heart. He was a true scientist, which de Lignac was not, but his philosophy scarcely differed from his friend’s. He had redone Needham’s observations and knew that they were faulty. But his

, hatred of “M. de Buffon and his entire clique”? also rested on philosophic convictions. He accused Buffon of materialism because he himself thought that animals had spiritual, although mortal, souls. Less rabid a defender of Heaven's interests than de Lignac, he was motivated by a personal dislike that the latter does not seem to have shared. It is unnecessary to draw a parallel here between Réaumur and Buffon. I shall not, therefore, compare fortune with fortune, vanity with vanity, worldly success with worldly success, nor the Trudaines with Madame Geoffrin. I would simply say that everything doomed the two scientists to do battle without understanding each other— their characters, their visions of science and the world, even the difference in generation. Réaumur was a contemporary of Voltaire’s, and Buffon of Diderot’s. In these combinations, the two halves of the century confronted each other. Nothing more was needed than the ambition of the younger against the tyrannical authority of the elder for their opposition to become open warfare. Buffon’s insolent scorn balanced the indirect attacks of Réaumutr. Neither of them was entirely responsible for the situation.

AS WE HAVE SEEN, the Sorbonne had taken alarm at certain propositions contained in the first three volumes of the Histoire naturelle. It sent Buffon a list of them on January 15, 1751, and he replied on March 12. His cos-

mogony, he said, was “a mere philosophical supposition,” and he protested that he believed “very firmly everything that... is reported on Creation” in Scripture. Concerning the notion of truth, he asserted that he had intended to speak neither of revealed truths nor—what was less likely —of metaphysical or moral truths. As to the soul and the nature of being, he abandoned his idealistic affirmations.

The Sorbonne was satisfied with these explanations.’° Others were less so—for example, Nouvelles ecclésiastiques, which refused to play the dupe “as the Sorbonical carcass had.”'*1 While more courteous, the abbé JosephRobert-Alexandre Duhamel was no less severe. Regarding the discussion of the existence of “bodies,” the abbé asked: “Does a Sorbonne exist?” }?? How could one not see that, far indeed from being a “mere supposition,” Buffon’s cosmogony was presented as a certainty?!?? Philosophically, what was meant

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by “evidence without certainty and a certainty without evidence?” 4 Duhamel did not cry Pyrrhonism and did not conclude positively that Buffon was irre-

, ligious, but he thought the Sorbonne had not performed its duty. No doubt he was close to sharing the opinions of the abbé de Lignac. Many others were subsequently to share them to a greater or lesser degree, and Buffon would always be thought unreliable on the subject of religion.’”

THE TONE CHANGED completely with the appearance in 1751 of a French translation of a work by Haller entitled Reéflexions sur le systéme de la génération de M. de Buffon, written as a preface to the second volume of a German translation of the Histoire naturelle,}*® which shows sufficiently clearly

that Haller harbored no hostility towards Buffon in principle. Indeed, the work is utterly courteous. Haller announced that he would adopt a point of view that was both scientific and religious,'”” but he did not confuse the two domains. On the scientific level, Haller, a physician, immediately recognized in Buffon the Hippocratic theory of the defluxus. Regarding spermatozoa, he preferred to accept, along with Needham, that they were creatures born in the seed rather than see in them a massing together of organic molecules, as Buffon did.!?8 He recognized that Buffon’s theory of the formation of the embryo explained the facts of heredity: “A number of questions that remain almost without solution in the development theory find their answer here.” '”? But

there were insurmountable difficulties, and foremost among them was the impossibility of understanding the action of the “internal mold.” Rather than explain heredity in this way, Haller asserted, “I would rather simply deny to M. de Buffon that children resemble their parents: if I prove this point, children will no longer be the image of their parents, and the rest of the edifice will automatically fall.” 19° In order to sustain this paradox, which illustrates

with particular clarity the “individualist” character of reproduction in the | eyes of the scientists of the first half of the eighteenth century,'*' Haller overlooked all external likenesses and cited his experience as an anatomist: © There is no man who in the internal structure of his body resembles another, and consequently no child that resembles its father. . . . There have never been two men all of whose nerves, arteries, veins, and even muscles and bones were not infinitely different.” Thus it was “almost impossible to give a description, and one is almost tempted to believe that in the formation of animals, nature not only has no model, but even that it works without a design.” **? Haller resisted this strange temptation, but it is curious that he should have felt it. A series of specific objections completed this first critique. The fetus had

494 THE PHILOSOPHERS SCIENCE parts that its father did not: umbilical vessels, thymus, sphenoid orifice, a _ double set of teeth in germinal form.'*? Acquired mutilations were not passed on: the Hottentots and the Swiss mountain people traditionally underwer.t the loss of one testicle, and their sons always had two at birth; it could not be said, however, that the mother furnished the missing testicle.!34 Even admitting that each organ communicated its form to the molecules, what force would bring these embryonic organs together into the proper order? One never saw an ear attached to a hand.’ Finally, the presence of a seminal fluid in women was very far from proven. The “glandular bodies” in which Buffon had thought he had found it were “not the cause of fertilization, they are its consequence: they appear in women only after conception” and ended up disappearing. Buffon, in any case, might be excused for not knowing this anatomical detail —he who had already learned so many things “despite the time he has spent in military service!” '%° (Buffon had never been a soldier; this mistake shows, however, that Haller took him for an amateur.) But the fact was there, and the “glandular body” could not contain seminal fluid. Haller seized the occasion to note that Buffon had not used “a very good guide to the anatomy of the female sex.” For the hymeneal membrane, whose existence he denied, nonetheless existed. Haller accompanied the assertion with a moral commentary: “Nature never jests.”'*” Nor does Haller! The religious issue was broached in the last fifteen pages, and only in order to answer some points of uneasiness that had been expressed. Haller did not share this uneasiness, first of all because Christianity had its own powers, in-

dependent of the proofs one might draw from nature; and secondly—and this was quite remarkable— because it was not necessary, in order to believe in God, to assume a purely mechanical and passive nature. The forces of affinity in chemistry, or universal attraction, took nothing away from the Creators power. Whether born from a germ or formed by a “force,” the eye was still made for seeing and still manifested divine wisdom. “It is therefore not the development itself, or the mode of production, that provides us proofs of

the existence of the Divinity” but “the wondrous relationship of the structure with its function.” Therefore, “if matter has forces that enable it to form things, we must not think that it has them from a blind destiny.” '** In this way, the ideas of Buffon and Needham were no more opposed to religion than those of Newton. Those of Buffon were still less opposed to religion than those of Needham, for an “internal mold” was still necessary in order to shape living matter and the first mold must have come from the hands of God: “Nature does not herself furnish the form in M. de Buffon’s way of con-

| Resistance to the New Science 495 ceiving it, she merely copies already-created molds.” 1? It seems as if Haller found this mechanism more reassuring than Needham’s “forces,” which he could not manage, despite his goodwill, to rid entirely of a blind and fortuitous character: “Who is it that makes these forces so knowing and so consistent in the production of animals? This consistency is sufficient to convince me, contrary to M. Needham’s experiments, that there is something previously formed in the generative seed of man and animals, even though one cannot say that it is a complete miniature of the whole body.” !*°

In the last analysis, then, Haller remained faithful to mechanism and | seems to have accepted preexistent germs. But his thinking was in no way rigid or aggressive. No doubt he was not inclined to separate religion from science: “The sciences are related to religion by their very nature. Without knowledge of the Supreme Being, they lead either to pride or to skepticism: without them, religion has always degenerated into superstition.” }#! Religion sustained the scientist in an attitude of admiration and respect for nature, whose rationality it at the same time guaranteed; it did not claim to dictate solutions or to cast interdictions. This position diverged quite widely from that of Buffon, but it allowed Haller to examine scientific opinions opposed to traditional mechanism with a cool head.'*? This position can be explained in part at least by the fact that Haller himself did not as yet have a clearly held opinion on the problem of procreation and the formation of the embryo. In 1747, in his Primae lineae physiologiae, Haller hesitated concerning the function to be assigned to the spermatozoa, but definitely rejected the preexistence of the germ in the egg.'43 “Never has one seen a fetus in the egg of a virgin,” '** nor in the ovary, nor in the male seed.14#° One had therefore to accept epigenesis, whose agent could not be the soul of the fetus, and that one could explain only through “some attractive force that brings together the particles of a viscous fluid in order to form from them strands, fibers, membranes, vessels, muscles, bones, and finally members. This seems more probable.” As for the “prudence that presides over so wise a structure,” it was obviously explained “by divine laws,” which one saw manifesting themselves just as clearly in crystals, simple vegetables, animal gluten, and cellular tissue. Epigenesis was in any case visible in the formation of the heart of the chick, in the regeneration of the polyp, and in plants. And how else could one understand monsters?!#° In this way, Haller had professed ideas very close to those | of Buffon. In 1751, he was judging preexistence more favorably, but he could

not condemn those who rejected it. It was observations on the formation of the chick in the egg, carried out in

496 THE PHILOSOPHERS SCIENCE minute detail over several years, that definitively converted Haller to preexistent germs. In 1757, he renounced epigenesis: “These issues are so difficult, and my experiments on the egg are so numerous, that I am proposing with less repugnance the contrary opinion, which is beginning to appear the more probable to me.” !4” Clearly, Haller was not inscribing dogma. But he had seen the embryo’s heart appear little by little and not take form. Above all, he had seen that the egg yolk, or rather the membrane enclosing it, was part

of the embryo’s intestines. Since then, he wrote, “it seems to me virtually demonstrable that the embryo is located in the egg, and that the mother contains in her ovary all that is essential to the fetus.” For “the yolk had existed in its mother’s womb, independently of the intervention of the male: the fetus must have existed there as well, although invisible, and enclosed in an amnios, always placed, apparently, on the yolk, but invisible because of its small size and transparency.” 48 The “development” of the germ was not, however,

a simple mechanism. Certain parts changed form, becoming longer; fluid parts became mucous, then solid, and at the same time opaque and visible. The growth of the parts was unequal, and the head was at first merely an appendix to the spinal column. Other parts changed position.'#? Haller thus built up a rather complex notion of the germ and its development: It seems very probable to me that the essential parts of the fetus exist from the outset; not, certainly, as they appear in the adult animal: they are set up in such a way that definite and preestablished causes, hastening the growth of some of these parts, hindering that of others, changing placements, making of previously diaphanous organs visible organs, giving substance to fluids and to mucosity, form at last an animal very different from the embryo, and in which, however, there is no part that did not

essentially exist in the embryo.’° ,

There remained the question of hybrids or of the action of the male seed. Haller recalled that this seed transformed the body of the male, giving rise to the beard in men and horns in certain animals. It could therefore act similarly in the body of the embryo, “impel the blood with more force in the auricular arteries” of the mule, for example, “and the objection is resolved,” even if the mechanics behind the action remained obscure.!*!

It would be difficult to say for sure whether Haller’s conversion to preexistent germs had no other real cause than his observations. Already in 1751,

before having undertaken them,’ he had been tempted by preexistence. Perhaps he had seen what he unconsciously wanted to see. We must not forget, moreover, that for him epigénesis could only be a gathering together of particles under the effect of an “attractive force” and observation offered no evi-

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dence thereof. A priori, this mechanistic vision of things prevented him from understanding how chance was excluded from these encounters of particles, and inclined him to find recourse in the germ as a principle of organization. The facts, such as he saw and understood them, confirmed him in this idea, without allowing him, however, to reduce “development” to a simple enlargement of the germ’s parts. Finally, one may say that Haller got as close to epigenesis as a mechanistic interpretation of the observed facts allowed him to. If Caspar Friedrich Wolff, whose investigations were almost contemporary, was able to go further, rejecting both preexistent germs and the gathering together of separate particles and conceiving of epigenesis at last in the modern fashion, it was no doubt because his observations were better than Haller’s but perhaps also because he was able to rid himself of traditional mechanism.’ Be that as it may, Haller’s conversion to preexistent germs was to make him more severe towards Buffon’s ideas. A mediocre refutation published by Charles-Joseph Panckoucke in 1761 was hardly able to weaken his conviction.>4 Dealing at the end of his great Elementa physiologiae corporis humani with the question of procreation in its entirety,’°? Haller multiplied the detailed criticisms of Buffon’s and Needham’s theory. Regarding spermatic animalcules, he judged the two scientists’ mistake to lie in their having confused them with other animalcules.’** In any case, there was no liquid in the ovary’s yellow body. In order to make these ideas acceptable, Buffon would have had to discover collections of organic molecules in the vesicles—that is, de Graaf’s follicles— before fertilization. But he had not found any.'’” Regarding the formation of the embryo, Haller set forth the hypotheses of Buffon and Needham'*® along with those of Leeuwenhoek and the ovists. But he judged Needham’s experiments to have been badly performed, either because

the flasks had not been heated enough to kill off the animalcules or because , other animalcules had been able to penetrate through the openings of the flasks,!°? and he showed that Buffon’s and Maupertuis’s attempts to conceive of a mechanistic epigenesis did not authorize an explanation of the facts.'%°

It is evident that for Haller the cause was taken for granted, and that it was , no longer even necessary to polemicize against gratuitous theories that were contradicted by the facts and condemned by all serious scientists. What proves that Haller’s position was not based upon experiment alone, however, is the manner in which he combated Wolff’s notions. He no doubt recognized the quality of his adversary and the exceptional value of his observations: Wolff was the strongest defender of epigenesis, the facts he had observed were beyond debate, and if preexistence could explain them, then one

498 THE PHILOSOPHERS’ SCIENCE had indeed to accept epigenesis.'*’ But Haller too had observed the formation of a chick over a long period of time.'®* Wolff had thought he was seeing animal gluten in the process of organization: in fact, it was already organized,

since one could make it visible by hardening it with distilled spirits. Wolff had thought he was seeing the formation of the heart: in reality, he had been seeing it appear, for the heart had to exist before acquiring visibility, given that the embryo was already alive.'®? Haller thus found himself obliged to bypass observation, to assume the existence of invisible parts, in order, despite the facts, to defend the only hypothesis that seemed plausible to him: preexis_ tence. In order to explain what he had seen, and in order not to have recourse

to the invisible, Wolff had had to grant living matter a mysterious force, a vis essentialis, which was as unacceptable to Haller as the vegetative force was

to Needham.!*4 How could this force, which would be simple, form all the different parts of different animals, here a chicken and there a peacock, and set each organ in its place?!® Haller’s choice was not dictated by the facts, but by his inability to free himself from a mechanistic conception of life, by his instinctive rejection of vitalism in any guise. There was no epigenesis because epigenesis was inconceivable. Better to assert the existence of what one did not see, of what one would never see. Neither the regeneration of a polyp cut into pieces'®® nor even the scarring of wounds’*’ could prevail against a priori refusal to grant living matter the power of formation and adaptation. On the part of an observer as attentive and rigorous as Haller, such an attitude is quite remarkable.

HALLER’ S CONVERSION tothe preexistence of germs overjoyed his friend Charles Bonnet. Since 1741, in fact, the Genevan naturalist had been persuaded of preexistence.'** He had had natural history revealed to him in reading the abbé Noél Pluche and then the Mémoires of Réaumur,'® both of

, whom were partisans of preexistent germs. His astounding observations on the parthenogenesis of aphids, which had earned him the certificate of correspondent of the Académie des sciences in 1740 at the age of twenty, had only confirmed him in this conviction. Malebranche had swept him off his feet because he “knew insects, loved them, and knew how to inspire admiration for them; he was imbued with the beauties of nature and the adorable perfections of its Author; he was still the high apostle of the preexistence of germs.” '”° In the winter of 1748, Bonnet had read Leibniz’s Theodicy, which had been “one of the most important moments in [his] intellectual life.” He

Resistance to the New Science 499

admired in it the manner in which “our modern Plato” “provided the loftiest notions of the wisdom and goodness of the Great Being, who had regulated from all eternity the destinies of all beings.” But “another branch of the same author’s philosophy could not but attach [him] powerfully to him”: “his ideas on the preexistence of germs and on that of souls.” *”’ In this fashion, everything had led Charles Bonnet to embrace the theory of preexistent germs: his earliest masters in the natural sciences and in philosophy, his earliest obser_ vations as a naturalist, and, more profoundly, the religious character of his intellectual temperament which inclined him to see the direct intervention of God everywhere, and to make everything depend as closely as possible on the Creator’s will. He had thus scarcely been bothered by the brief metaphysical exchange he had had in 1745 with a certain Cuentz, “metaphysician from St. Gall,” the author of a Systéme nouveau sur la nature des étres spirttuels,'’? who was a defender of “the purely mechanical formation of organized bodies.” The specific subject under debate was the regeneration of the polyp and the problems it raised for the partisans of the soul of animals, including Charles Bonnet; but admitting that these “wondrous reproductions . . . were due originally to preexistent germs, Bonnet had preferred to assume “contrary to M. Cuentz, that a soul preexisted in the germ as well.” '’° In short, Bonnet’s conviction was as strong and deep as could be. He had expounded it in 1745 in the preface to his Traité dinsectologie..’* He had made it one of the basic principles of the Méditations sur (univers on which he had been working from 1748 to 1753, and from which were to issue the Considérations sur les corps organisés and the Contemplation de la nature.’”? He had even com-

posed “a sequence of chapters” on this question, and had thought it possible to publish them separately. But he had remained undecided: For, although the principles I had established rested upon well-documented and varied facts, there was none, however, that was as decisive as I wanted and as was re-

quired by the logic of a naturalist, which served as my guide in my meditations. I had therefore made up my mind not to publish and to wait until time and the research of the finest physiologists should provide me with the knowledge I lacked in order to bring my work to completion. I had even dared assume that we would manage someday to determine the most basic fact of all, namely, the preexistence of the germ in the female.!7°

Haller’s discovery concerning the egg yolk and its membrane was for him this “basic fact.” He sent his manuscript to Haller, who approved it; he took it back, revised it, and finally published it in 1762 under the title of Considérations sur les corps organisés. The book fulfilled specific intentions:

500 THE PHILOSOPHERS SCIENCE I had proposed three things for myself in the composition of this work: the first, to put together in summary everything most interesting and most certain concerning the origin, reproduction, and development of organized beings that natural history provided; the second, to combat the different systems based upon epigenesis, and in particular those of MM. de Buffon and Needham; the third, to set up against those strange opinions a hypothesis in better conformity with the facts and with the principles of sound philosophy.'7”

The defense of preexistent germs thus led Bonnet into the ranks of the opponents of the new science. The first eight chapters of the Considérations sur les corps organisés were taken from the Méditations sur (univers, and they are what Bonnet had sent to Haller in 1758. They contain, broadly sketched, a complete theory of reproduction through preexistent germs. In the opening page, the true character of this theory is clearly set forth: “Philosophy, having understood its incapacity to explain the formation of organized beings mechanically, has happily conceived that they already existed in miniature in the form of germs, or organic corpuscles.” 178

The dilemma was therefore simple: “Either one must undertake to explain the formation of organs mechanically, something that good philosophy

acknowledges to be beyond its power: Or one must accept that the germ actually contains in miniature all the parts essential to the plant and the animal.” '”? Even if the theory derived its strength from the inadequacy of mechanism, no fact could be adduced against it. The multiplication of worms or plants through cloning necessarily assumed preexistent germs.'*° In the circumstances, it was evident that Buffon’s ideas, which Bonnet examined in chapter 8, were false a priori: I shall simply remind my readers of the astonishing apparatus of fibers, membranes, ligaments, tendons, muscles, nerves, veins, arteries, etc., that enter into the composition of an animal’s body. I shall request them to consider attentively the structure, the relationships, and the functioning of all these parts. I shall then ask them if they find it conceivable that so composite, interrelated, and harmonious a whole could be formed through the mere collaboration of molecules moved, or directed, according to certain laws unknown to us. I shall ask them to tell me if they do not feel the necessity we are in of admitting that this admirable machine was designed in miniature at the outset by the same Hand that traced the design of the universe. As for me, I must ingenuously admit that I have never found it conceivable that the matter could be otherwise. When I tried to form an organized body without the help of a primitive germ, I always remained so dissatisfied with the efforts of my imagination that I have well understood that the enterprise was absolutely beyond its reach.}*!

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More specifically, one might wonder how organic molecules were molded

when they were inalterable, how they took the form of the parts without having been assimilated into them, how parents could provide children with parts they did not possess, as was the case with the mule, bees, and mutilated animals.'** Finally, Buffon’s theory was “ingenious” but that of preexistent germs was “more probable, easier to grasp, and subject to fewer difficulties or disadvantages.” '*° Overall, the critique was modest, but the aim to reject was absolute. As for Needham’s observations, Bonnet quickly ran through the abbé de Lignac’s objections: we did not know the temperature that animalcules could tolerate; those seen in infusions could have come from the air. Réaumur had in any case recognized that the supposed moving globules were true animals.!8* The critique here was even hastier, indeed summary, but the rejection was just as complete. Numerous reflections on and facts about reproduction were set forth, if rather untidily, in the continuation of Bonnet’s work, written between 1758 and 1762.'°° In Bonnet’s eyes, Haller’s observation on the egg yolk was proof positive of the preexistence of the germ: “The yolk is . . . an essential part of the chick: but the yolk exists in the egg that has not been fertilized; the chick therefore exists in the egg before fertilization.” 8° Whereupon one can assert without hesitation “that there is no true generation in nature; but we improperly call generation the beginning of a development that makes visible to us what we previously had not been able to perceive.” '*” Bonnet now felt in a stronger position to condemn Maupertuis, Buffon, and Needham. “The physicists who have held that there is no germ in unfertilized eggs have taken their pet idea for the ordering of things.”’** Buffon’s “observations on the chick are the complete ruin of his edifice.” '*? And Bonnet even apologized for having spoken of it: Many readers will no doubt reproach me with having expanded upon the system of M. de Buffon. They will claim that dreams that are not even philosophical did not deserve one’s attention. I shall not attempt to justify myself concerning this reproach; but I admit that I felt something was due the celebrity of the dreamer and the singularity of his dreams.!?°

As for Needham, he is wrong to claim “that there is no germ in the grain that has not been fertilized.” Not that his opinion was absurd: But on what does M. Needham’s assertion rest? Only on the fact that [even] with the best microscopes, nothing is found in the seed of a plant until the tops of the stamens have

discharged their dust. Who does not see that this manner of reasoning is not correct,

5022 THE PHILOSOPHERS SCIENCE and that it deduces nonexistence from invisibility? Does one discover the germ in the unfertilized egg [even] with the best microscopes? Nonetheless, do we not have direct proofs that it exists? !?!

In brief, Needham’s great mistake lay in wanting to believe only what he saw. [he reproach is rather amusing coming from a naturalist who then protested against the abuse of reasoning by analogy: “People have sought to judge the totality of beings by a small number of individuals. They have drawn general conclusions from particular cases. They have hastened to establish rules before having studied all the beings that they gratuitously assumed to be subject to them.” '?? Bonnet had, in fact, found the key to all reproductive phenomena in the studies of Haller, who knew everything about the regeneration of the polyp and of worms better than anyone did, certainly better than Buffon. Haller set out the facts at great length, recalling Réaumur’s observations on crayfish: as far as Haller was concerned, preexistent germs provided a natural explanation for everything.’?> Haller’s work returns like a leitmotiv. Henceforth, everything Bonnet saw was a new proof, even the regeneration of a sectioned worm: Nature seems to have enclosed in miniature, in a kind of bud, the parts that insects _ reproduce in place of those they have lost. One sees this with the naked eye, so to speak, in the multiplication of worms from cuttings and in the reproduction of crayfish claws. The new part passes through all the stages of growth through which the animal itself has passed in order to arrive at the state of perfection. One finds in it at the outset the same essential form, the same organs that it will display later on in a larger state. The circulation of the blood is guite visible in the infinitely delicate vermiform appendix that grows at the hind end of an earthworm, and that is destined to become a new hind end. Arteries imply veins; both imply nerves and many other organs. All this coexists, therefore, for how can one conceive that different parts destined to form a same whole, to collaborate towards a same end, and all of whose actions are therefore in complicity or relationship, would be produced one after another by apposition, or by a hidden mechanics? How could one accept the idea of such a formation, when one has arrived at the determination that all the parts of the chick coexist long before they become perceptible to our senses? Why is the part that reproduces itself so disproportionate to the one it is going to replace? Why is it so soft, so delicate, so fine? Why are the articulations so tight, so close to one another? Because it is not the former whole or the stump that grows and forms the new production; it is a new whole that is developing in the old, with the help of the fluids furnished by the latter. I do not deem it possible to deny this consequence when one has carefully followed the regeneration of worms that multiply from cuttings, and when one has a hundred times with one’s own eyes seen and seen again

Resistance to the New Science 503 this wondrous regeneration. But the physicists who have fought the opinion I am adopting seem to have been more strongly motivated by the glory of giving birth to a new system than by the more philosophical and less acclaimed pleasure of studying nature in an insect. I am not setting up a system here; for I am not undertaking in any way to explain how the animal is formed: I am assuming it to be preformed from the outset, and my assumption rests upon facts that have been well observed.!94

Perhaps nowhere is the unconscious passage from observation to system more clearly manifest than here, nor the immense difficulty in seeing things as they are. It is understandable that, after this, objections of a metaphysical order were negligible, and that Bonnet did not hesitate to assume in the germs the presence of souls responsible for the regeneration of polyps and worms.’?> And when he returned one last time, and at length, to Needham’s observations, all he could do was regret that this “skillful observer,” remarkable in his “precision of mind, ... his sincerity, and . . . his love for the true,” remained convinced without “any positive proof of the truth of so strange an

opinion. '° Still, if Bonnet was as convinced as possible of the preexistence of germs, he was not unaware of the difficulties they posed. Even before 1758 he had observed that one had to grant the male seed a rather important power over

the preexistent germ. Otherwise one could understand neither hybrids nor the resemblance of children to their fathers.!?” At the end of the Considérations, he returned at greater length to these problems, admitting that, through fecundation, the germ did not simply develop, “but receives still more modi-

fications, which affect its exterior and its interior. . . . The seminal fluid therefore contains molecules that correspond to different parts of the male; for it imprints upon the germ points of resemblance with different parts of the latter.” !°8 Since one could not accept the “internal molds,” it was “the male’s organs of generation [that] therefore separate out from his blood or his lymph molecules analogous to different parts of his body.” '?? In the case of hybrids, the molecules from the male of one species were fitted to awaken and nourish the germ of a neighboring species, while modifying it. This “latitude” did not, however, extend to the reproductive organs, which, for lack of precisely adapted molecules, were obliterated. “The seed of the jackass does not open all the vessels proper to the horse’s reproductive organ . . . and this is enough for the mule to be impotent.” 7°° By the same token, the definition of the germ became broader: “One must not think that the germ possesses in miniature all the features that characterize the mother as an individual. The germ bears the original imprint of the species, and not that of individuality.

504 THE PHILOSOPHERS SCIENCE It is, in miniature, a man, a horse, a bull, etc. ..., but it is not a certain man, a certain horse, a certain bull, etc.” 2” This “latitude” allowed a better comprehension of freaks of nature, which Bonnet took up in conclusion. He did not imagine for an instant that the germ might be monstrous originally. The difficulties that Jacques-Bénigne Winslow had adduced against Louis Lémery and the theory of accidents disappeared if one thought of the perfection of vegetable or even animal grafts, such as the grafting of one polyp onto another, or of the spur of a cock onto its comb,”°” and especially if one accepted that the germ was not simply an animal in miniature: All its parts have forms, proportions, and locations that greatly differ from those that evolution [i.e., development] will endow them with. This is so much the case that if we could see this germ enlarged as it is in miniature, we would not be able to recognize it as a chick. ... The germ is, so to speak, composed merely of a series of points, which will form afterwards into lines. These lines will become prolonged, will multiply, and will produce surfaces.”

Among germs so constituted there might be unions that the anatomist would no longer understand when he examined the developed fetuses. On the other hand, “if two parts join together to make just one, a single part sometimes divides to form two that are distinct and alike.” There was no need to assume the union of two germs to explain a double womb found in a woman: “It had probably depended on causes that had acted upon the viscera itself, and in particular upon the inner surface of the peritoneum, which had lengthened it excessively and had directed its development in such a way as to create a monstrous duplication out of it.” ?° Finally, the influence of the seminal fluid might be a cause of monstrosity. The mule was a kind of monster. But there were still clearer instances. Bonnet borrows Réaumur’s story of the family of Gratio Kalleia, who, afflicted with hexadactylism, had transmitted the anomaly to some of his children and grandchildren.2” The germs of his children were surely normal; it was therefore the father’s seminal fluid that must have acted on the germs: It would not have begotten new parts, whose first outline had not existed before: it is well enough established that nothing is begotten. But it must have determined, with greater force and according to directions contrary to the natural order, the development of different parts, either membranous, or cartilaginous, or bony, of the metacarpus and the metatarsus. It must have caused divisions and an excess of growth, which would have brought into existence these monstrosities whose causes we are attempting to discover.*°°

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There remained an awkward detail: Gratio had had a daughter with four offspring, one of whom had six toes. Réaumur and his informant saw an argument against preexistence in this.7°” Bonnet, who believed in neither the power of the maternal imagination nor the existence of a female seed capable of acting upon the germ, preferred to assume that this single excess digit was “the effect of an accidental cause,” rather than give up his system.?% In fact, his system excluded any resemblance between child and mother. For, if it was “certain that the germ resides originally in the female . . . it is scarcely less cer-

tain that the germ is not begotten in the female and that it has existed from all time.” 2°?

Bonnet thus remained faithful to preexistent germs to the very end. But he had been led to provide a far broader and freer idea of the germ, which allowed development a considerable role and even a certain liberty. The germ was no longer “merely an organized body reduced in size”; one had by this term to understand “all preordination, all preformation of parts capable in itself of determining the existence of a plant or an animal.” ?!° It was a regulatory principle, and the scientist was not authorized to see in it a response to all problems: “People should have attempted to see further into the manner in which development occurs before seeking to penetrate the way in which generation functions.” *"’ This was a perfectly wise comment and valid for both sides, for those who conceived of the germ as preexistent just as for those who saw it as having been formed instantaneously through a gathering together of molecules. “Evolution does not in itself exclude epigenesis. The animal formed through juxtaposition from the encounter of the two seeds would

be subject to the law of development.” 7! Whatever the cause, the develop- . ment was natural, and therefore observable. And Bonnet did not hesitate to grant the causes of this development the power to modify the initial germ quite significantly in order to produce not only, as we have seen, hybrids or monsters, but even new species: “There is no doubting that the species which existed at the beginning of the world were less numerous than those that exist today. The diversity and multitude of conjunctions, and perhaps even the diversity of climates and of nourishment, have given rise to new species, or to intermediary individuals.” ?? The examples given show that Bonnet was really thinking of his new varieties and not of species, which for their part were inalterable: “No change, no alteration, complete identity. Prevailing over the elements, time, and the tomb, the species are preserved, and the end of their perdurance is unknown to us.” 74 Despite this, development was no longer a mere extension of parts.

506 THE PHILOSOPHERS SCIENCE Nature and the play of secondary causes took on a new importance that brought Bonnet closer to the new philosophers. Thus it was not surprising to see him conceiving of the action of the male seed on the germ through molecules “analogous” to the parts of the body whose features were to be transmitted; this could pass for a borrowing from Buffon. But there were other, more essential points in common. Not only did Bonnet believe in the graduated chain of beings and regard the polyp as the animal closest to plants,” he also, and above all, no longer regarded reproduction as an unfathomable mystery: “Reproduction is one of those secrets that nature seems to have kept for herself. I believe, however, that we shall wrest it from her one day.” 7'° By dint of observation and experiments, no doubt. But Bonnet was far indeed from banning hypotheses: You cannot have too many conjectures on an obscure subject. They are so many threads that can lead us to the truth by different routes, or give us the occasion to discover new worlds. Conjectures are the fiery sparks from which sound physics lights the torch of experience. I approve of the modest timidity of physicists who stay strictly with the facts; but I cannot blame the ingenious daring of those who at times undertake to penetrate beyond them.*!7

And it was in this very spirit that he had presented his theory of preexistent germs, at least before Haller’s observations: as a conjecture or even a “romance” that he set up against the romance of epigenesis. Despite this opposition, the links between Bonnet and the new philosophers could clearly be seen by attentive readers.

Among these attentive readers was the abbé de Lignac, who, in his capacity as royal censor, had the Considérations sur les corps organisés banned in Prance.?!* That did not keep the author of the work from devoting ever more

attention to the “natural” aspects of the formation of beings. Without entering here into details that would oblige me to retrace the entire history of a very complex idea, I must at least note that the Palingénésie philosophique, published in 1769, goes further in this direction than the Considérations of 1762 or the Contemplation de la nature. In putting the “Tableau des considérations” that had served as a preface to the Contemplation at the head of his new work, Bonnet repeated his defense of conjecture: To banish the art of conjecturing from physics entirely would be to reduce us to pure observation; and what good would observations be to us, if we did not draw the slightest consequence from them? We would endlessly amass materials in order never to build. We would endlessly confuse the means with the end. Everything would remain isolated in our minds, whereas everything is bound together in the universe.?’?

| Resistance to the New Science 507 It was a matter of discovering relationships in order to get to the causes, which had to be physical: “What would we think of a physicist who, to explain the

most difficult phenomena of nature, were to refer to the direct action of the Primary Cause? Would we not require of him that he first demonstrate the inadequacy of the physical causes?” **° Bonnet was obviously thinking, not of the supporters of preexistent germs, but of the defenders of “plastic forces,” for these forces were in his eyes non-

natural agents of the divine will. He thus intended to remain within nature, whose mechanism was admirable enough for us to see in it the wisdom of God. What more admirable was there, in particular, than the power of reproduction of organized beings? Preexistent germs were the work of an infinite wisdom. “And if it were possible that the sole laws of mechanics could suffice to form new, individual wholes, it would merely seem all the more admirable to me.”??! Bonnet would not go so far as to accept epigenesis. But for him,

henceforth, the created universe was not immutable. Perhaps it had undergone great revolutions, and the account in Genesis might well be describing to us, not the creation of the world, but the last of these revolutions.?*? In these circumstances, one might believe that “the plants and the animals that exist today have arrived by a sort of natural evolution of the organized beings that populated the new world that emerged directly from the hands of the Creator.” ??? This surely does not mean that Bonnet had adopted a transformist vision of life. Species were not born one from another but underwent an “evolution” analogous to that of the germ, in the course of which they were subjected to external influences—for example, “the periodic changes of the seasons” 224 which led them to modify themselves, each one individually: “I am easily persuaded that if we could see a horse, a hen, a snake in their initial form, in the form they had at the time of Creation, it would be impossible for us to recognize them.” ?”?

In just the same way, we could not recognize the germ of the chick before development had begun. By thus extending to species what he had earlier said of germs, Bonnet ended up, oddly enough, in the company of Diderot. Both men conceived of species changing over the course of time under the influence of circumstances. For the one, they had been created; for the other, they had been born fortuitously. But this fundamental difference did not enter in here, any more than did the question, regarding “development,” of whether the germ had been created or formed by an “encounter of molecules.” Bonnet no doubt conceded species less scope for modifying themselves than Dide-

508 THE PHILOSOPHERS SCIENCE rot did, but it is nonetheless remarkable that he granted nature the power to

produce these modifications. :

Analogously, Bonnet was led to give a definition of the germ that would be neither broader nor less rigorous, but far less mechanistic and geometrical. Henceforth, this word might designate “any kind of original preformation, from which an organic whole can result as from its direct principle.” ?° This was a

definition that modern science would not disavow,””’ for it prejudged neither

the means of this preordination nor the nature of the development that it directed. Bonnet was perceptibly moving away from Haller, and he would finally understand that the celebrated observations on the preexistence of the chick were less positively demonstrative than he had believed.?7* Still, no matter how far he went down this path, Bonnet would remain to the end among the opponents of the new philosophers. For he was not content with calling — and quite legitimately—for a regulatory principle in embryonic development that would be more effective and more easily conceivable than “forces of at_ traction” or “vegetative principles.” It did not occur to him that this principle of “preordination” might come from nature, even if directed by God. It could only be the result of a direct and particular creation. If he misconstrued Buffon’s effort to justify this preformation through the “internal mold,” while at the same time accepting a very similar idea to explain the action of the male seed upon the germ, it was because the “internal mold” was a natural organ, and for Bonnet, nature simply could not create a form, even in the image of a received form. There was no formative power except in God. A profoundly religious spirit, by nature a metaphysician and mystic as much as a careful observer, Bonnet was literally enchanted by the preexistence of germs. Not without some naiveté, after having entitled one of his paragraphs “Considerations Favorable to this Hypothesis,” he wrote: “The first is that I cannot make up my mind to abandon so beautiful a theory as that of preexistent germs, in order to embrace purely mechanical explanations.” *? Inasmuch as they were for him the imprint of God upon His creation, preexistent germs became the basis of Bonnet’s philosophy.?*° This deep conviction did not keep him from evolving, from giving up an overly rigid mechanism or an absolute fixity of species. He may even have found in the depth of his faith the daring to approach without fear certain problems reputed to be dangerous, like those of psycho-physiology.”*? But if he had enough independence to share some of the new philosophers’ opinions and enough breadth of mind to combat without acrimony those of their ideas that he did not share, he remained nonethe-

Resistance to the New Science 509

less one of their opponents, and all the more intractable in that he opposed | them, not for accidental reasons, but because of his entire vision of the world.

THESE METAPHYSICAL REASONS seem to have remained foreign to Lazzaro Spallanzani, who was in the last analysis to be the most fearsome opponent of Needham and Buffon.”** The abbé Spallanzani was 35 years of age and was a professor of “philosophy” in Reggio Emilia when he undertook to redo Needham’s experiments on infusions. He had, a priori, no great liking for a system that brought into play “plastic forces”; but among all the scientists who had risen up in opposition to the new theory, none had “ever thought of examining it by the route of experience.” ?°> Needham was traveling in Italy at the time. Spallanzani entered into correspondence with him, and the two men, despite their scientific opposition, were to maintain relations of esteem and even friendship.?34 Now, Spallanzani’s first observations confirmed those of Needham, who boasted of this ephemeral agreement to Bonnet.’ But, perhaps impelled by an instinctive mistrust, Spallanzani continued his investigations and finally arrived at entirely different conclusions. His Saggio di osservazioni microscopiche concernanti il sistema della generazione

de signori di Needham e Buffon, published in 1765, methodically demolished Needham's ideas.’*° The question examined was that of the nature of the animalcules found in the infusions. Needham had seen in them “vital beings.” Spallanzani noted that they reacted to heat and to cold like larger animals,

that their movement had every appearance of spontaneity, and that their form was constant. He therefore considered them to be true animals.?” The great question, however, was whence they came. Working with a faulty understanding of the notion of “vegetative force,” Spallanzani at first strove to establish links between the sprouting of the grains in the infusion and the emergence of the animalcules.”** The results seemed to support Needham: “I therefore had the occasion to notice that the birth of the animals always followed, and in a uniform fashion, the progress and the pace of the vegetation, and that it followed them even in the most exact proportion, with this difference, however, that by keeping the seeds from vegetating, one did not always keep the animals from appearing.” 7°?

Still, Spallanzani did not stop there. No doubt he was convinced deep down of a mistake on Needham’s part. He therefore noted that this “harmony” between the vegetation of the seeds and the emergence of the animalcules “seems, at first glance, a fairly plausible proof that vegetation must be

sIO THE PHILOSOPHERS SCIENCE seen as the physical cause of these phenomena.” However, “the matter would

seem to be very ambiguous and doubtful,” for “one sometimes thinks one is perceiving a real and physical connection between two things, similar to that which is found between the effect and its cause, whereas, in truth, there exists only a linkage deriving merely from a simple condition [i.e., a casual relationship — Ir.].” 4° One might imagine that “a gentle and moderate heat, which would be proper to make the infusion material germinate, would also have the property of hatching the animals out of the eggs contained in these same infusions,’ no matter what the origin of the eggs: the air, the sides of the glass, or the infusion itself.?4! The experiments therefore had to continue. Spallanzani started by observing the grains sprouting in the water again. He saw the vegetable filaments, he saw the animalcules, but he did not see

that the former gave birth to the latter. On the other hand, he saw animalcules emerge from tiny eggs.?4? But he also, like Needham, saw “tiny bodies”

animated by a “blind agitation.” Was this “an obvious proof of the passage of matter from the vegetable to the animal kingdom”? No, for these “tiny bodies’ seemed rather to be “the dwelling place of the animals in the infusion.” 243 Nothing was thus resolved. More work was necessary. A whole series of experiments illustrated to Spallanzani that the boiled infusions gave birth to animalcules just as well as the others, as Needham had noted.?*4 Now, the heat had surely destroyed any eggs that might have been in the infusions, whatever the anonymous author of the Lettres 4 un Amériquain might , have said.?#° The eggs could thus only have come from the air. It was therefore necessary to redo Needham’s great experiment on the juice of roast meat, poured into a hermetically sealed flask and then set in burning embers, but in which the animalcules still had appeared. Spallanzani started out by demonstrating that the animalcules could appear in a relatively rarefied air, and in a flask whose mouth has been sealed in flame, provided that the volume of air was sufficient.”*° Finally, he filled nineteen vials with diverse infusions,

sealed them with flame, and plunged them for an hour in boiling water. No animalcules appeared in these infusions as long as the vials remained closed. Spallanzani’s conclusion is remarkable in its exactness and prudence: Let us now recapitulate all that has been said, and let us conclude that by hermetically sealing the vials, one is not always sure to prevent the birth of the animals in the infusions, boiled or done at room temperature, if the air inside has not felt the ravages of fire. If, on the contrary, this air has been powerfully heated, it will never allow the animals to be born, unless new air penetrates from outside into the vials.

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This means that it is indispensable for the production of the animals that they be provided with air which has not felt the action of fire. And as it would not be easy to prove that there were no tiny eggs disseminated and floating in the volume of air that the vials contain, it seems to me that suspicion regarding these eggs continues, and that trial by fire has not entirely done away with fears of their existence in the infusions. The partisans of the theory of ovaries will always have these fears and will not easily suffer anyone’s undertaking to demolish them.?47

It was true, Spallanzani added, that the fire could have rarefied the air contained in the flasks. But we had seen that the rarefaction of the air was not an obstacle to the appearance of the animalcules.?*8 As we shall see, Spallanzani’s essay utterly delighted Voltaire. Charles Bonnet expressed his gratification and drew from these observations the conclusion that most mattered to him: “A false philosophy is attempting to present

us with these animalcules as bastards of nature. . . . You have been able to legitimize them. . . . Multiply as much as possible the proofs of their legitimization and you will render an important service to natural theology.” **? Better than any other, this statement indicates the climate of the debate. Needham did not, however, throw in the sponge. His objection was the very one that Spallanzani had foreseen: In flasks sealed in this way, the presence of a certain quantity of pure air, proportionate to the quantity of the fluid contained and to the macerated substance, is absolutely necessary for the generation of these vital beings, in the theories both of the germ-bearers and of epigenesis: now, in the way in which he treated, and subjected to torture, his nineteen vegetable infusions with no necessity, if he was merely seeking to destroy the supposed germs that he assumes might have been able to exist on the inner walls of these flasks, it clearly follows not only that he greatly weakened, or perhaps totally destroyed, the vegetative force of the infused substances, in proportion to their greater or lesser resistance, but also that he completely corrupted, through the exhalations and heat of the fire, the small portion of air that remained in the empty part of his vials; it is thus not surprising that his infusions, treated in this manner, should have given no sign of life; and it had to be so, as he himself suspects in suggesting to me the true answer to his objection, which he seems to be expecting from me. Here, then, in a few words is my final proposition and the result of all my work. Let him use, in redoing his experiments, substances sufficiently heated in order to destroy all the supposed germs that one might believe attached either to the substances themselves or to the inner walls or suspended in the air inside the flask; let him seal his flasks hermetically; let him then immerse them inside their flasks in boiling water for several minutes, merely the time it takes to harden a hen’s egg and to kill the germs of silkworms or of other insects; in a word, let him take all the precautions he will, as long as he seeks only to destroy the supposed alien germs that come from outside, and

5IZ THE PHILOSOPHERS SCIENCE I maintain that he will still find those microscopic vital beings in sufficient quantity to support our principles: if upon opening these flasks, having let them sit for the time necessary for the generation of these bodies, he does not find anything vital, or any sign of life conforming to these conditions, I shall abandon my system and give up my ideas. This is, I believe, all that a judicious opponent can reasonably require of me.?°°

Spallanzani therefore set to work once more, although he was utterly convinced of Needham’s errors and had already clearly expressed his thinking on the supposed “vegetative force.” **' Before infusing the seeds, he subjected them to the highest possible temperatures, even charring them in the flame , of a burner. The infusions of burned seeds, left in open air, were infested with animalcules. How could one think, however, that the “vegetative force” had been able to withstand calcination??? On the other hand, he managed to seal his flasks without the flame heating the air contained in them,?*? and determined that the unboiled infusions became populated with animalcules in the vials sealed in this way.?°4 Having thus disposed of a preliminary objection, he subjected his sealed-flask infusions to immersions of different duration in boiling water, then to different temperatures. At the end of these experiments, he found himself impelled to distinguish between two sorts of animalcules: those “of higher orders,’ large, medium, or small, that a temperature of 28 degrees Réaumur prevented from appearing,’ and the animalcules “of the lowest order,” whose appearance was prevented only by leaving the infusion for a little less than three-quarters of an hour in boiling water.2*® With that, Spallanzani could write that his “liking” for the germ hypothesis had been “changed into a conviction.” 7°” For the sake of conscience, he also repeated Needham’s experiments on infusions of crushed grain or degermed grain, but without ever seeing a vegetable filament become an animated globule in them.”** Buffon and Needham had been completely mistaken, and Spallanzani definitively adopted the theory of the preexistence of germs, a theory that “seems taught to us by the universal voice of nature” and that was confirmed more strongly every day.”*? The animalcules came from germs and were true animals, even though some of them reproduced through division: Bonnet had in fact clearly explained how a being possessing a soul could re-

produce in this fashion.” With this, Spallanzani was able to go after Buffon’s strange ideas on the nature of spermatic animalcules as Bonnet had asked him to do.**' And his observations so completely contradicted those of the French naturalist that he no longer dared believe his eyes and, without Bonnet’s encouragement,

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might have given up on the whole business.?°? The spermatic worms were not

born in the thready material of the sperm but were part of the sperms fluid, even when it was collected directly from inside the animal.?°* Their tail was not a thread that they got rid of, but a true tail, which they did not lose, for they did not change form, just as they did not divide, did not become smaller and smaller or swifter and swifter, and did not live from two to eight days but only a few hours.” In short, as Haller had guessed, Buffon had not been observing true spermatic animalcules but animalcules born from the decomposition of the sperm, which Spallanzani too had been able to observe.?** With this, the theory of organic molecules was utterly destroyed, for despite perpetual movement, which they shared with certain insects, spermatic worms were true animals, as was proved by their reactions to heat and cold, which were similar to those of other animals.*°° They were worms, analogous to intestinal worms. Since Haller had demonstrated that the fetus came from the female, “it is clear that the tiny worms provided by the male could not be fetuses.” What, then, was their function? “I believe this question to be above the sphere of human knowledge,” replied Spallanzani.’°’ There is no need for us to pursue Spallanzani in his famous investigations into the reproduction of batrachia. Let us simply note that after having destroyed the legend of the aura seminalis,°* having performed many experiments on seminal fluid, and having carried out artificial insemination even in mammals,”°° he remained convinced to the end that the preexistent germ was contained in the egg and that the spermatozoon played no role in reproduction.””° Such a mistake on the part of an observer of his caliber is astonishing. Possibly he had not been able to perceive any difference between a frog’s egg that was fertilized and one that was not. Possibly, as well, he had thought he had fertilized an egg with a drop of sperm he had thought to be freed of any animalcule.””* He who had been able to determine with such perspicacity the

causes of error in Needham’s experiments had in turn become the victim of what he saw, or rather of what he did not see. Without speaking of a real “theoretical mentality,” for if the facts had confirmed Needham, Spallanzani would surely have bowed to them, one may suspect that even before undertaking his experiments, the great Italian scientist “sensed” that Needham was wrong, and that this feeling had contributed to his perspicacity. This initial victory placed him irrevocably among the opponents of epigenesis according to a logic imposed by the scientific notions and attitudes of his century. Thereafter, one may suspect, he was a victim of the “theoretical mentality”

514 THE PHILOSOPHERS SCIENCE of his colleagues Haller and Bonnet. His experiments -had led him to demonstrate the role of spermatozoa in reproduction, but he paid no attention, being persuaded in advance that this role was nonexistent.

FROM MALESHERBES to Spallanzani, all the scientists whose reactions to Buffon and Needham we have been examining belonged to the same intellectual and spiritual clan. They all asserted that they were defending the rights of experience against the theoretical mentality, and Réaumur, Haller, Bonnet, and Spallanzani were indeed genuine observers. But it is clear

that their observations, far superior no doubt to those of Buffon, were for most of them and perhaps even for Spallanzani, only a means of verifying what they already knew, namely, that epigenesis and spontaneous generation were physically impossible. What united them all, prior to any experiment, was that they were mechanists and Christians. As mechanists, they could conceive of laws of living matter only as a form of the laws of motion. No doubt this was no longer exactly traditional mechanism. After 1760, Haller, Bonnet, and Spallanzani accepted the mysterious power of irritability, just as the astronomers had to accept attraction. But even though he was the least conformist among the opponents of epigenesis, Bonnet could not get himself to think that the polyp was a “purely irritable being.” And however large the role granted by him to the “development” of the germ, that development had no other cause than an adjunction of “molecules” that got lodged in the

germ's substance as in the meshings of a net. The mechanist in him had to reject Needham’s “vegetative force” and also, more unfortunately, Wolff's vis essentialis, along with the observations that had accompanied it. At least he might have given a warmer welcome to the ideas of Buffon. But the mechanism of the opponents of epigenesis was not the triumphant mechanism of Descartes: it was the mutilated mechanism of the first half of the eighteenth century, which refused to grant nature any power other than that of running machines created by God. Epigenesis always remained a “chance encounter of molecules,” and reason rebelled at the thought that a being as complex as

an animal could be born from this play of chance. Nature could only form | “bastards,” as Bonnet put it. And preexistent germs were not only the means of the divine order. They were also the proof of the interest that God took in His Creation, a proof that was reassuring to reason and comforting to a soul seized with terror at the idea of an eternal universe abandoned to chance. Only a “speculative atheist” could accept epigenesis, first of all because his “somber imagination does not place plausibilities in the balance,” and then —

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and especially—because “in order to nourish his melancholy, he needs to banish happiness and reason from the universe.” ”’”” The paternal presence of the Creator was demonstrated to the disturbed heart by the preexistence of germs. Pre-romantic sensibility gave a more intimate resonance to a feeling that the abbé Pluche had already known. The greatest opponents of Buffon and Needham remained faithful to the tradition of the Christian naturalists of the first half of the century.

SIDE BY SIDE with this Christian tradition, however, there was deist thought, which the new philosophy also disturbed. This deism and the convictions it led to in science could have had no better defender than Voltaire, who had been its embodiment since at least 1734, when he published the Lertres philosophiques.’”* In these letters, in fact, Voltaire, Maupertuis’s convert,

did not stop merely at defending universal gravitation against the Cartesian vortices. He defended Newton against the charge of having resuscitated occult qualities. But when he writes, echoing Roger Cotes, that “it is the vortices that one might call an occult quality, since no one has ever demonstrated their existence,”?74 he showed that, like many of his contemporaries, he no longer knew what an occult quality really was. Otherwise, he would not have said of attraction: “The cause of this cause is in the bosom of God,’ ?”? which is precisely the definition of an occult quality; that is to say, a natural and observable effect that science cannot account for because it results from a direct action of God. Newton himself had not been so definite.?”° For Voltaire, scientific research very quickly ran up against God’s mystery: “Procedes huc, et non ibis amplius.”* This injunction from Job was the true motto of Voltairean science.”’’ Voltaire’s Traité de métaphysique provides us with further enlightenment, even though scientific problems are not dealt with there for their own sake.

God was demonstrated through the order of the world and by the need to establish an origin for the chain of existing beings.?”* The world’s order implied a creative intelligence and justified the prudent search for final causes. No doubt we had reason to believe “that a pasture was not made essentially for horses.” Implicitly, Voltaire was rejecting the excesses of George Cheyne and William Derham, which he would ridicule in Candide. The opposite excess, however, was none the wiser:

*“Thou shalt proceed thus far, and shalt not go beyond.” —Tr.

sI6 THE PHILOSOPHERS SCIENCE Here, we must above all reason with good faith and not seek to fool ourselves; when one sees a thing that always has the same effect, and only that effect, that is composed of an infinite number of organs, in which there are an infinite number of movements, all of which collaborate in producing the same action, it seems to me that one cannot, without a hidden misgiving, deny a final cause. The seed of all plants and of all animals falls into this category: would it not be foolhardy to say that all this is unrelated to an end??7?

It is not surprising to see preexistent germs put in an appearance here: they had their place in Voltaire’s universe, in which matter in itself possessed neither motion nor thought,”*° a tenet that alone sufficed to destroy the claims of the materialists;7*' a universe without its own activity, in which everything issued directly from the hands of the Creator and could not help but preserve indefinitely the form it had received. Obviously, species could not vary. “Never has a moderately enlightened man suggested that unmixed species degenerate.” It was certain that “pear trees, pines, oaks, and apricot

| trees do not come from a single tree.” Likewise, and whatever the opinion of “a man dressed in a long, black cassock,” it was certain that the different species of man, “the bearded whites, the blacks with their woolly heads, the yellows with their manes, and the beardless men do not come from the same man. *°* No matter that Voltaire was confusing races and species here.

His attack on the Bible and the unity of the human species linked him to the tradition of “freethinking” skepticism, which he was even closer to when he refused to distinguish man from animal and assumed the same difference between the civilized white man and the black as between the black and the ape or between the ape and the oyster, the difference being everywhere one of degree of organization, never one of nature.’*? This traditional critique found reinforcement in the immutable conviction of Voltaire and, in the last analysis, the philosophy of the Traité de métaphysique looks very much like that of Fontenelle. The name of Newton, moreover, never appears, and references to Locke and Samuel Clarke remain very vague. In brief, it is as if English thought, or at least that of Newton, were still foreign to Voltaire.?*4 The fourth discourse of the Discours en vers sur [homme repeats in passing the theme of the limits on scientific knowledge, of which Voltaire reminds the scientist: Reason guides you: move forward in its light; Make still more progress, but limit your course. Your path must stop at the edge of the infinite; There starts the abyss; it must be respected.?®°

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“Thou shalt not proceed beyond.” This was the ignorance that man could not escape, and the greatest were subject to it, a Réaumur,”*° a du Fay, a Maupertuis. Ask a doctor how digestion works: He lifts his eyes to heaven, he bows down, he cries: “Ask of that God who gave us our life.” 287

For of all of nature’s secrets, those of life were the most inaccessible. No one would ever know ... by what subtle mechanics The eternal Artisan causes bodies to live.288

Analogously, the sixth discourse exposes the illusions of those who take man to be the end of Creation, and God takes the trouble of disabusing them on this point: “You, the work of my hands, sired by the same father, You who bear,” He tells them, “my divine mark, You were born for me, nothing was made for you; I am the unique center to which you all relate.?®?

It is possible to say that with this, Voltaire’s thought was definitively set especially in the area of science. The Eléments de la philosophie de Newton, in

1738, added nothing new of importance to these questions. Still, one thing had changed: Voltaire’s idea of God. The somewhat pale image of Fontenelle’s

God, always in danger of vanishing into the “eternal, independent, and immutable laws of mathematics,”?° found in the Traité de métaphysique was replaced by the much brighter image of Newton’s God, “who has created and arranged everything freely.” ?°’ The notion of this divine freedom is very important. For not only did matter “receive gravitation from God,” just as it did motion and, in certain beings, sensitivity, but also, “If the planets turn in one direction rather than in another, in unresisting space, the hand of the Creator therefore directed their course in this direction with absolute freedom.” *?? In appearance, nothing had changed: for Fontenelle, God had already been the Creator of all things. In fact, everything was different as soon as God became the free Creator of things. This freedom, irreducible to all mathematicization, gave Newton’s God something like an extra degree of existence and, so to speak, more “presence” in created nature. The heavens truly sang His glory.??? But at the same time, this God was unknowable: philosophy was “powerless to teach us what He is, what He does, how and why He does it. It seems to me that one would have to be Him in order to know it.” ?*4 Was He a reasonable God? A pointless question: He was reasonable, since He

58 THE PHILOSOPHERS SCIENCE was God. And what about the existence of evil? This was a problem, but one that took nothing away from the necessity of an intelligent creator.2®° God was present in the universe, and the proof of final causes was consequently “the most powerful in Newton’s eyes,” *?° as well as in Voltaire’s. By the same

token, everything that attested to an order in nature and especially to foresight, acquired a privileged value. Nothing, moreover, manifested that order and foresight better than living nature: If matter of any sort, given motion, were sufficient to produce what we see on Earth, there would be no reason why dust shaken up in a barrel should not produce men and trees, nor why a field sown with grain should not produce whales and crayfish instead of wheat. It would be vain to reply that the molds and dies that receive the seeds do not permit it; for one would always have to come back to the question: why are these molds and dies so invariably determined? Now, if no motion, no art has ever been able to make fish rather than wheat come up in fields, nor medlars instead of lambs in the belly of a ewe, nor roses on an oak tree, nor sole in a beehive, etc. ... , if all these species are invariably the same, must I not straightaway believe, and with some reason, that from matter and motion nothing except eternal chaos would be born without these designs? All experiments confirm me in this opinion. If I examine on the one hand a man or a silkworm and on the other a bird or a fish, I see them all as formed since the beginning of things; I see in them only a development.??”

It is evident that Voltaire did not wait for Diderot or Needham in order to answer the objections of the materialists, and that the preexistence of germs already had a leading place in his arsenal. It is understandable as well that, despite everything separating them, the abbé Pluche should still have been for Voltaire “the estimable author” and even “the wise author of the Spectacle de la nature and of the Histoire du Ciel,” even if he was not a Newtonian.?”8 Above all, one can understand that Voltaire should have protested energetically against those who attributed to him the idea that “weight is essential to matter, whereas it is “a quality... given by God.” 7?” The importance of this distinction was to appear later on. Upon leaving his philosophical exile at Cirey, Voltaire gave himself over to other games. “Vanitas vanitatum,” echoed the “Courte réponse” of 1744, “et metaphysica vanitas.” *°°* Would science be any less a vanity? The “white negro examined by Maupertuis briefly attracted Voltaire’s attention. “Here at last is a new wealth of nature, a species that no more resembles ours than spaniels do greyhounds.” *” The tone is trifling and bitter: Voltaire was not * “Vanity of vanities: and metaphysics, too, is a vanity.” —Tr.

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thinking of genetics but of the foolishness of the human race. The tone is more serious in the “Dissertation . . . sur les changements arrivés dans notre globe.” Without delving into this famous letter, which in any case does not entirely deserve the sarcasms generally heaped upon it, I shall simply note that in it Voltaire defended the idea of a completed, orderly creation against people like William Whiston, John Woodward, Thomas Burnet, and other theorizers who were juggling with catastrophes in order to explain the topography of the globe.*°” After 1746, Voltaire abandoned science. But he was soon

to learn that there were other vanities in this world besides those of metaphysics and geological theory: love and life itself, as well as the friendship of scholars and kings. In 1749, a few days after having left for Cirey, then for Lunéville where

Mme du Chiatelet was about to die, Voltaire had received from Diderot a copy of the Leztre sur les aveugles. In one sentence he resolved the problem of teratisms that this “ingenious and deep” work had raised; and his solution was that of Joseph Guichard-Duverney and Winslow: the manner in which an anomaly was compensated still demonstrated a very intelligent being, and we could not debate the moral aspect of the issue because we did not know God.?°? Had Voltaire read the reports of the two anatomists? In any case, his reply fitted in with the logic of his thought. Did he at that point see the risks

the newcomer [Diderot] was making “the true faith” run? Diderot replied in turn with a reassuring, although ambiguous, letter. And then Voltaire had other problems on his mind. It was a personal event, the dispute and falling out with Maupertuis, that finally led Voltaire to criticize the tendencies of the new philosophy publicly. In 1752, he seized the opportunity offered him by the publication in Dresden of his former friend’s Oeuvres. In a long review published in the Bibliothéque raisonnée, he hammered at Maupertuis, while maintaining an even tone.>% He reproached Maupertuis’s “Essai de cosmologie” with having tried to de-

stroy the proof of the existence of God through final causes, by use of the argument that spiders ate flies and the earth was covered with seas or uninhabitable mountains. But flies were made in order to be eaten, the seas and mountains were made to make water circulate and to fertilize the earth. As for moral evil, besides the fact that people exaggerated its importance, and that the objection was old hat, this ancient issue “did not call into question the supreme Intelligence: it calls into question the idea of His goodness that we fashion for ourselves.” Finally, the proof of the existence of God through the principle of least action was illusory:

520 THE PHILOSOPHERS SCIENCE Nothing could more effectively cast doubts upon the so true and necessary dogma of the existence of an infinitely wise and just God than reducing all the moral and physical proofs of this truth to an algebraic formula. A geometrical theorem is true by necessity. The three angles of a triangle are equal to two right angles because it cannot be otherwise. Now, the necessity of things is precisely the contrary of an infinitely powerful and free God. What is necessary excludes a choice. It is in the choice of means that the great geometrician Newton found one of the most striking points of conviction for the existence of the creative and governing Being.>°

It is clearly visible here that the apologetic value of final causes was bound. up with the notion of a free God. As for Vénus physique, it was quickly dealt with. Using a technique at which he excelled, Voltaire ridiculed the system simply by summarizing it. He paid a little more attention to the style, supposedly as ridiculous as the ideas.>°° Finally, he came to the “Lettre sur les progrés des sciences.” Voltaire’s summary merits careful study, not for the ideas but for the polemical strategies. It is pointless to become indignant over so much bad faith and even dishonesty. All means were justified as long as they caused harm. Maupertuis, the “native of Saint-Malo,” would henceforth be the leading character in Voltaire’s puppet show. He would always reappear escorted by his Patagonians and Laplanders. Nothing stopped Voltaire, not even the death of his enemy [in 1759]. The Histoire du Docteur Akakia offers nothing that was not already in the Bibliotheque raisonnée, except for a few allusions to the “eels” of Needham, whom Voltaire does not name and whom he could not yet have known. Ultimately, the only interest for us in this business is that it might have been able to focus Voltaire’s attention on a mode of thinking far more distant from his own than he had imagined during the time of his friendship with Maupertuis. But he does not seem even to have had this benefit from it. In 1756, his Dialogues entre Lucréce et Posidonius discussed the formation of beings without any allusion to attraction. The spontaneous appearance of living forms was brought up with the same image as in 1738: matter tumbled in a barrel, from which “a regular shape” emerged.’ If, moreover, Voltaire seems to be refuting the Lettre sur les aveugles, it was no doubt only because Diderot echoed Lucretius in it. There was nothing new in the Essai sur les moeurs either, in which Voltaire repeated the notion of the original diversity of human races, each having been born in the land it inhabited, and the albino blacks being placed in an intermediary slot between the Hottentots and the apes.°°* “Each climate has its different productions. . . . The master of nature has populated and varied the entire globe. The pines of Norway are certainly

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not the fathers of the clove trees of the Moluccan Islands. . . . No one, surely,

dreams of thinking that the caterpillars and slugs of one part of the world originated in another: why be surprised that in America there exist some animal species and some races of men similar to ours?” 9°? We should note, however, that despite appearances, Voltaire was not content simply to repeat what he had written in the Traité de métaphysique, or that at least the perspectives were no longer the same. He took great care, now, to recall that all men were alike “in their passions, and through universal reason,’ *!° as well as through the instinct that led them to come together in societies.?"' It was now less a question of contradicting the Bible and more one of showing that species were immutable; that is, that everything in nature was the direct work of God. In 1764, Voltaire’s Dictionnaire philosophique appeared. On the questions of interest to us, it was astonishingly moderate. The article “Atheism” expressed pleasure that “there are fewer atheists today than ever, since the philosophers have recognized that there is no vegetant being without seed, no seed with-

out design, etc...., and that wheat does not come from rot. Geometricians who are not philosophers have rejected final causes, but the true philosophers accept them.” *’? Let us then be indulgent of the atheists’ errors. Let us, moreover, distinguish the true final causes, inscribed in nature from those that existed only in frivolous brains.*’? Was matter created or eternal, was motion essential to it or not? In truth, no one had any idea.?"* In truth, we did not know anything. How was thought formed? How was a child formed?

How did a grain of wheat “rise up to produce a stalk laden with an ear?... How does the same plot of earth produce an apple at the top of one tree and a chestnut on the neighboring tree?” >!” It would seem as if Voltaire, mobilized for other battles, allowed himself to be taken over where these questions were concerned by a peaceful skepticism, hardly disturbed by the memory of Maupertuis, the “geometrician who is not a philosopher.” Was he then completely unaware of the new science? Most probably not. The same year, 1764, he took it into his head to write a review of Bonnet’s Considérations sur les corps organisés. No doubt it was an opportunity to recall the incomprehensible

wonders of nature: “What we call oddities are innumerable; all must seem miraculous, because all is inexplicable.” "© An opportunity as well to launch a swift attack on Vénus physique and to affirm once more the necessity of “re-

turning to the ancient opinion that all germs were formed at the same time by the hand that arranged the universe.” 3!” Still, not all of Voltaire’s knowledge came from Bonnet. And above all, he clearly and faithfully expounded the theory of organic molecules. He saw its defects and did not adopt it, but

522 THE PHILOSOPHERS SCIENCE this did not prevent Buffon from being “an eloquent and very enlightened philosopher.” 38 Needham, whom Bonnet had criticized at length, was not even named. How are we to explain such serenity? The fact is that if Voltaire knew the new scientific theories at least indirectly, he still considered them inoffensive: he was still unaware, by all appearances, that they had been serving for fifteen years as the foundation for a powerful renewal of atheism. It was in 1765 that Etienne-Noél Damilaville went to the patriarch in order

to explain the new philosophy to him.*” The results of this revelation are well known: within the space of thirteen years, that is, until death forcefully

| silenced him, Voltaire would write more than twenty-five works, treatises, dialogues, putative letters, fictive questions, verse and prose satires, meditations, or tales, all of them directed in whole or in part against atheism and its scientific underpinning. While the “Questions de Zapata, the “Examen important,” most of the Questions sur l’Encyclopédie and the “Homélies” pursue the battle against the z#fame [the Catholic Church —Tr.], Maupertuis, Needham, Buffon, and de Maillet put in their appearance to round out the cast of Voltaire’s puppet show, escorted as the moment dictated by Epicurus, Descartes, or Bernard Palissy. From the “Questions sur les miracles” and the “Philosophie de lhistoire” until the Lettres de Memmius a Cicéron and the Dialogues d’Evhémére, and passing through the Singularités de la nature and several entries in the Questions sur l’Encyclopédie, Voltaire was to avenge the honor of God on the backs of eels, mountains, and shells. He would even perform some hasty “experiments” in order to persuade himself more firmly that the limepits of Touraine were not the result of fossilized shells and that the polyp was not an animal. For he had understood that these wretched little details called into question the existence of God. The first victim of this explosion was Needham. By an odd coincidence, he was in Geneva at the very moment when Damilaville was at Ferney. Worse still, he had just foolishly gotten himself involved in a dispute on miracles in which Voltaire was— anonymously — playing the principal role. The opportunity was too good to pass up. Voltaire threw himself upon Needham, never to let go. One can hardly speak of a debate. Voltaire made it clear once and for all that Needham had imagined “he had discovered, with his microscope, that flour made from grain attacked by ergot, steeped in water, immediately turned into tiny animals resembling eels. The fact is false,” Voltaire added, “as an Italian scientist has demonstrated”;*”° and this was to be the only specific allusion to Spallanzani’s experiments, which Voltaire was already aware of 37! but that he did not bother to set forth in detail. For

Resistance to the New Science 523 [the fact] is false by virtue of a much higher reason, that is, that it is impossible. If animals were born without seed, there would no longer be a cause for procreation; a man could be born from a clump of earth just as well as an eel from a piece of dough. This ridiculous system, moreover, would inevitably lead to atheism. It happened, in fact, that certain philosophers, putting faith in Needham’s experiment without having witnessed it, claimed that matter could organize itself; and Needham’s microscope was reputed to be the atheists’ laboratory.>??

This was why Needham was wrong. This was also why Voltaire flew into such a fury, leaving aside the vexation at having been personally taken to task in a polemical exchange that he himself had unleashed, but in which he had counted on remaining anonymous.*’? From then on, every insult was legitimate. “Irish Jesuit,” “slanderous Jesuit,” “wretched Needham,” who “imagined people were referring to him when they spoke of Jesus Christ,” because he had changed flour into eels. “Let him stay with his eels, since he is their comrade insofar as they move on their belly, if not insofar as they wriggle.” 324 Let “Needham the Patagonian,” Needham “the Eel fellow” be what he chose,

“priest, atheist, deist, or papist .. . , I couldn't care less: but, by Jove! I will teach him to be polite.” °° Soon, the “Questions sur les miracles” turned into a clownish farce in which Needham reappeared at every moment in a grotesque posture. He would still be appearing, again with his eels, again accused of having ruined preexistent germs and favored atheism, in the “Défense de mon oncle” in 1767, and in 1768 in the Singularités de la nature, where atheism founded upon spontaneous generation was labeled an “eternal shame of the human mind.” 7° During the year 1768, Voltaire increased his barrage: Needham made an important showing in the Homme aux quarante écus, in Les Deux Siécles [the Siécle de Louis XIV and Supplément du siecle de Louis XIV,

although these did not originally appear in 1768 — Ed.], in LABC, in Les Colimacons du révérend pére L’Escarbotier, and in the Précis du siecle de Louis XV?’ In 1770, the Questions sur l'Encyclopédie again rehearses the history of the “eels,” of their inventor, and of Maupertuis’s “Systéme de la nature,” supposedly founded upon that ridiculous observation.*”* The last act of the comedy came with Evhémére conjuring up the “demi-druid of the Cassiterides” %??*

Such rancour against a man who never once replied bears witness to the importance that Voltaire attached to the question of spontaneous generation.’*° ‘To reject preexistent germs was to deny the divine origin of living *At the time, druid was a code word for “priest,” and “the Cassiterides” —a name given in antiquity to some islands supposed to lie off the west coast of Europe—referred by metonymy to Ireland; Voltaire took great delight in this kind of poetic obliquity, particularly when it veiled a nastiness. — Tr.

: 524 THE PHILOSOPHERS SCIENCE beings, to accept that matter in motion could organize itself, to deprive God both of a power and of a proof of His existence. Voltaire returned to these issues ceaselessly, even when he was not hounding Needham. The necessary existence of germs was repeatedly recalled, in the Philosophe ignorant, the Singularités de la nature, the Colimagons du révérend pére L’Escarbotier, the Précis du siecle de Louis XV, the Questions sur l’Encyclopédie, and the Lettres de Memmius a Cicéron.**’ Lucretius, albeit so profound as a moralist, had always been wrong about the physical world,**? and his explanation of the birth of animals

through the fortuitous motion of matter, with the elimination of nonviable monsters, was a prodigious absurdity: let all those who, like Diderot, sought to resuscitate it take heed.*** The marvels of the human body must force even an Epicurean to believe in God.3#4 It would be madness to grant nature the power to form or merely to modify so admirable a machine. Voltaire returned several times to the original diversity of human races, a proof of the fixity of species,>*’ and he did not believe that the maternal imagination could in any way alter the form or color of a human being.**° All “transmutation” was impossible, and Buffon was wrong in saying that wheat was a human creation. For “we do not believe that with jasmine one has ever developed tulips.” *°” Buffon, whom Voltaire rarely names and whom he most often alludes to by

way of a laudatory circumlocution, had made the great mistake of allowing himself to be seduced by Needham and of maintaining the untenable theory of organic molecules.*** And then, what could one say about the ridiculous consul Maillet and his claims that man has descended from a fish? 97? “That’s all quite well, but I find it hard to believe that I am descended from a cod.” 34° De Maillet was crazy, Maupertuis was an atheist, Needham raved, Buffon

went astray. Even the precise Réaumur was foolishly mistaken concerning bees and had ruined “several families” with his metallurgical theories and his “chicken ovens.’ 34! When all was said and done, the polyp looked “much more like an animal than a carrot or an asparagus does.” 34 Who would ever explain the manner in which slugs’ heads regenerated? 34? All theories were empty. The first responsibility of the scientist was skepticism: In physics as in all the world’s matters, let us begin by doubting. . . . Let us examine through our own and others’ eyes. Let us be fearful, then, of establishing general rules. .. . The most certain way is thus not to be sure of anything, either in heaven or on earth, until we have well-documented news of it. “Caliginosa nocte premit Deus”: “God covers his secrets in the depth of the night,” Horace says. ... This is not what people call lazy reason; it is enlightened and controlled reason, which knows that a lowly being cannot penetrate the infinite.344

_ Resistance to the New Science 525

The mystery of generation was deeper than any other, but it was simply one mystery among others. In the last fifteen years of his life, Voltaire repeated the non ibis amplius of 1734 more forcefully than ever. The Philosophe

ignorant is no more than a long development on this theme; the protagonist of the Homme aux quarante écus, about to become a father, has to renounce knowing “how children are made”; he will learn only “what the philosophers have imagined, namely, how children are not made.” >4 Singularités de la nature heaps question upon question without reply and displays through its very title that man cannot hope to discover an order in those scattered and “singular” phenomena, in those “astonishing effects” of which “nature is capable.” 34° Questions sur l’Encyclopédie returns tirelessly to our different points of ignorance.34” Everything happens without our knowing why. Everything is an “occult quality.” Voltaire no longer bridled at the expression. He

loudly proclaimed it, he revindicated it: “For a very long time, people have made fun of occult qualities; they should make fun of those who do not believe in them.” 348 “Alas! are not all the wellsprings of nature occult qualities? The causes of motion, of forces, of generation, of the immutability of species, of feeling, memory, thought: are they not very occult?” 34? “All action is an

occult quality. . . . Alas! everything is occult.”*°° Evhémére states it once again: “Everything is an occult quality. The term constitutes the respectable admission of our ignorance.” **! And if all was occult, it was not only because human reason was weak and limited; it was above all because everything depended directly upon God. Nature could not answer the philosopher interrogating her: “They call me nature, and I am all art. ... Go interrogate the One who made me.” *”? In truth, nature did not exist: “There is no being that constitutes nature. . . . God has given to us, to animals, to vegetables, suns, and grains of sand, all that we have, all our faculties, all our properties.” >*> “All is an emanation from that supreme Being.” 3°4 “In Deo vivimus, et movemur, et sumus.” °°? * Science showed this better than any other study: “One need only delve a bit to find an infinite abyss. One can only feel awe and keep silent.” 9*°

Feel awe, keep silent, and “cultivate our garden.” The lesson of Candide is already to be found in the sixth discourse of the Discours en vers sur l'homme:

Let us be content with our destined blessings, | As passing and limited as ourselves. Without vainly scrutinizing what our Master can do, What the world was, what it should be, * “In God we live, and move, and exist.” — Tr.

526 THE PHILOSOPHERS SCIENCE Let us observe what it is, and pluck the fruit Of the treasures it contains and the goods it produces.3>”

With the passage of time, Voltaire was to be far less convinced that these blessings were “destined” and that we needed only stretch out our hands in order to pluck the “fruits.” But he would still believe that practical action was preferable to speculation. The Précis du siécle de Louis XV, dealing with “the progress of the human mind” during the period in question, speaks of mecha-

nized looms, agriculture, a project for bringing in water through canals, progress in clockmaking, and even a secret for making seawater drinkable. In comparison with this “progress of the human mind,” pure science had merely lined up a series of failures or silly theories. Voltaire vented his ire and

with a single stroke demolished Réaumur, Maupertuis, Needham, Buffon,

: and de Maillet: nothing but “foolhardy systems,” “deceptive experiments, “vain ideas,” and “extravagance.” *°* One had to admit that the “inventors of mechanical arts have been far more useful to men than the inventors of syllogisms, the Questions sur l Encyclopédie reminds us: “He who thought up the

shuttle wins out with the greatest of ease over him who thought up innate ideas.” °° The aged poet would have liked to cultivate the land: A good farmer is a hundred times more useful Than were of yore Hesiod or Virgil,>°°

a hundred times more useful, too, than the physicists who had “seen with full evidence that limestone was composed of shells, and that the earth was made of glass. This is what they have called experimental physics. The wiser among

us have been those who cultivated the earth, without inquiring whether it was made of glass or clay.” *°' Every system, every attempt at explanation, was

merely empty babbling: “That is well put,” replied Candide, “but we must cultivate our garden.” It was, then, starting in 1765 that Voltaire most clearly asserted his positions on science and, more specifically, on biology. But his thinking had taken shape around 1730 and had preserved the mark of its age up to the end. Voltaire was a contemporary of Réaumur’s and the abbé Pluche’s, of Nieuwen-

tyt's and Derham’s. Only one question separated them and he had strongly underlined it: the place of man in Creation. Voltaire could not believe that the infinite God, the sovereign creator of all things, would have given any special attention to such silly animals, “philosophic grubs,” “featherless bipeds,”

as men. The skeptical tradition received an unexpected treatment in this regard: man was all the smaller and weaker in Voltaire’s eyes inasmuch as God

Resistance to the New Science 527

was greater and more powerful. In certain texts, it is no longer a question of philosophy but of pure feeling, of a disgust, a nausea at the crazy doings and the atrocities of the human species. At times, Voltaire felt overcome with a frenzy of denigration, a rage to debase this vain and contemptible animal.>” Even in a more temperate humor, the idea that God could have made the universe for man seemed to him irresistibly comical: it was Pangloss fancying that the Supreme Being had arranged everything for the comfort of Milord the Baron of Thunder-ten-tronck. In 1737, God had already said to the beings that issued from his hands: You were born for me, nothing was made for you; I am the single center to which you all relate.364

After 1765, the Philosophe ignorant reminded the abbé Pluche that it was “hard to imagine that monsieur the prior and monsieur the knight were the kings of nature.” 364 The Questions sur l’Encych pédie repeated the lesson in either an amusing or a serious tone.*® Voltaire scarcely returned to it afterwards, because after 1770 it was less urgent to expose the abuses of final causes than to defend them against the atheism that denied them. His thinking was none the less clear on the point, which was essential to his vision of the world. A nature that was not made for him could inspire no emotion in Voltaire’s man. If “the heavens tell of the glory of God,” it was to God himself that they repeated it. Zadig had been able for an instant to lift his soul up to the stars: “He fancied men then as they in fact are, insects devouring one another upon a tiny atom of mud. . . . His soul soared into infinity and contemplated, detached from its senses, the immutable order of the universe.” But quickly “brought back to himself and consulting his heart,” he found himself once again what he really was: ephemeral and unhappy.*°° And yet this tale was composed in a happy time: there would be no star to guide Candide’s wanderings, embarked as he was in the universe like the rats in his highness’s vessel.>°”

If, then, Voltaire’s deism rejected the naive enthusiasms of a Pluche or _ a Derham and did not fancy God to have invented tides in order to carry _ ships into port, his conception of nature and science was very close to theirs. Nature was a vast machine, which God had created with perfect wisdom and complete freedom. In such guise it came from the hands of the Creator, and as such it subsisted and would subsist, because God’s laws were immutable, and because the machine was absolutely passive. The species were fixed, each , plant, animal, or human type was created individually and adapted in advance to the climate in which it was to live.3°® Nature neither modified nor

528 THE PHILOSOPHERS SCIENCE produced anything: “There is no generation as such; all is merely development, °°? everything came from a preexistent germ, created by God on the first day. And as if all this, already found in Fontenelle, still gave the better part to nature, Voltaire added to it ideas from Newton. Nature was not even a clock wound up once and for all that then ran by itself once its pendulum had been set in motion by the sovereign Workman. God intervened endlessly in nature, not only to preserve its being, but also to give it motion, of which a determined quantity did not exist in the universe,’”° to maintain the power of attraction in matter, the power in animals to feel and to move, and the power in man to think. Thus the universe was “all in God.” Moreover, ignorance was the law of man. Not only because human reason was powerless: Voltaire did indeed gather in the legacy of the skeptical tradition on this point, but he went still further. Man was ignorant and would always be so, because in each of his investigations he immediately ran up against the unfathomable mystery of God: “Everything is an occult quality.” No doubt the action of God was infinitely reasonable, but this took nothing from its mystery. It was vain to wish to understand: “We can only feel awe and stay silent.” Voltaire thus took to its final consequences the thought of the scientists of the first half of the eighteenth century. Between the new philosophers and himself, combat was inevitable and without hope of reconciliation. The common struggle against Christianity imposed a certain self-control on the adversaries: Voltaire publicly praised the Encyclopédie. But among the Encyclopedists, he would have only one true friend, d'Alembert, who was closer to him in the last analysis than to Diderot. Diderot himself, the “brother of Plato,” was an estimable man; but then, Voltaire had never read the Réve de d‘Alembert” Buffon was a power to be reckoned with: Voltaire pelted him with flowers. But Needham and Maupertuis, de Maillet and the “Systéme de la nature” (so luckily anonymous) had no protection, and Voltaire was able to sink his teeth into them with no constraints. In the last analysis, he was to be the new philosophers’ most violent and irreducible opponent, more fearsome and obstinate than people like Haller, Bonnet, and Spallanzani, and this precisely because he was not a scientist. By way of a completely natural contradiction, he refused reason the power to understand the world, but he preserved, when it came down to his own reason, its power to deny facts that got in his way. Haller had been able to modify his conception of “develop_ ment” and Bonnet his conception of the germ. They had both had to grant nature a power of some sort. Voltaire did not know such scruples. For him, certain facts were false because they could not be true—that is, because they

Resistance to the New Science 529

contradicted his philosophy. At times he hit the mark, but we should not be taken in: it was by virtue of the same motivation that made him in toto, and for the same reason, reject fossil shells, Needham’s “eels,” and the animality of the polyp. Anything that lent nature any sort of activity was suspect a priori,

because giving to nature or man meant taking away from God. The conclusion was inevitable, and it will surprise only those who fail to recognize the religious character of his thinking: if Voltaire put so much aggressive energy into combating a philosophy and a science that promised man knowledge of the world, it was because he was defending his faith.

Conclusion to Part III

THE SCIENTIFIC PHILOSOPHY of the first half of the eighteenth century had never been a body of doctrine. The work of philosopher/scientists, it expressed a vision of the world that no one had attempted to systematize. Its underlying tendencies were clearly asserted, but its contours remained fuzzy, and agreement was quite easy among researchers more concerned with techniques of observation than with problems of metaphysics or epistemology. First and foremost, though, the new scientific thought was notwithstanding a philosophy. Whatever their intellectual origins, the new scientists were consciously and deliberately philosophers. As a result, they pursued their own paths, which have had to be studied separately here. Nonetheless, they had many points in common, the foremost of which was precisely the stated intention of being philosophers, of reflecting on the value of human knowledge and science, and of using scientific knowledge as the groundwork

for a world system, a complete explanation of the universe. | The basic character of this philosophic intention requires that we seek the reasons for their undertaking outside science itself. No doubt the activity of the biologists had slowed down somewhat in 1740. But the entomologists were very active, and the discoveries of Bonnet and Trembley had just demonstrated that investigations in this area could raise the most astonishing and serious issues. Still, the scientists of the new generation were not to pursue this path. Entomology would soon lose its fascination for the minds of the

period, and this development was to be felt not only among the philosopher/scientists studied in this book: it was a far more general phenomenon. Enthusiasm for insects had had its day, and after the death of Réaumur,

Conclusion to Part III 531 many naturalists can be seen focusing on other problems, in particular that of classification, long neglected in France. It is as if the minds of the period were tired of those meticulous and desperately slow investigations—a body of knowledge that was so fragmentary and so painstakingly acquired, involving a countless population of beings seemingly so alien to man. “A complete insectology” was impossible. This had been known for some time. Now, the tendency would be to consider it of little interest. Insects had to be put in their true place: “A fly should not occupy more space in a naturalist’s head than it does in nature.” On every side, and even among the opponents of the new science, attention again turned to the grand issues of biology, which gave intelligence an object deemed worthier of it and seemed to lead more directly to a knowledge of man himself. At its inception, then, the new movement in scientific thought incorporated a reaction against the nonhuman character of the previous period’s science, a sort of general impatience and a desire to skip over the inexhaustible minutiae of indifferent facts in order to take on the grand questions directly involving man. Among these philosophers, however, this reaction assumed far more specific and complete forms, determined by the philosophical influences they had undergone. Those among them who had been formed by Newtonian astronomy approached the natural sciences with the intention of finding laws in them, no longer merely facts, and of studying the activity of nature rather than admiring the works of God. This attitude is very clear in Maupertuis and Buffon. Needham arrived at it through other paths, no doubt under the influence of scholasticism and a particular interpretation of Leibniz, to whom Maupertuis also owed a large part of his thought. All this led to the assigning of an activity of its own to nature. It was, however, possible to accept the idea that this activity had been willed and directed in advance by the Creator. Needham and even Maupertuis were not tempted to go beyond this; science, after all, needed nothing more in order to constitute its own universe, and to study the workings of secondary causes without henceforth fearing inconsiderate interference by an all-powerful God. In reality, this intermediary position was very difficult to maintain. Voltaire was to accuse Maupertuis of atheism, and Needham found himself co-opted by Diderot and d’Holbach. The reason was that the science of the first half of the eighteenth century had so completely made nature directly and continually dependent on God, and had so habitually proved the existence of God through the marvels of nature, that it had become impossible to grant nature

532 THE PHILOSOPHERS SCIENCE activity of any sort without taking something away from the divine prerogatives and without raising questions concerning the very existence of God. The scientist who wanted to study nature, and who sought thereby to grant it an autonomous reality, found himself virtually obliged by the logic of the period to rid himself completely of God by denying Him, and to adopt a philosophy that could better than any other give everything to nature because it took everything away from God.

The new science therefore led to atheism, but it had not given birth to ~ it. Café society had been scoffing at “Monsieur de l’Etre”* and His naive admirers when the philosophers of 1745 were still in their cradles or on their school benches. Clandestine manuscripts reveal the existence of this com-

posite atheism, in which Epicurus dragged behind him tatters of Spinoza, Leibniz, or Descartes. Even among deists, the notion of God was notably weakened: not everyone shared the enthusiasms or terrors of Voltaire. As for ' the God of the Bible, He had become irrelevant. This, then, and not, apparently, the demands of science, was the point of departure for the philosophers in question. No doubt for Maupertuis, and certainly for Buffon, philosophical reflection went hand in hand with scientific reflection and may even have preceded it: Buffon had rejected the Mosaic cosmogony before realizing that the logic of his scientific thought required the hypothesis of a “physical” cosmogony. Many of the new science’s afhrmations or rejections were part and parcel of traditional Epicureanism, whose vigorous expression in the scientific domain at the end of the seventeenth century has been noted.

In short, it is certain that the scientists of the new school had not in-

vented the philosophy that suited their conception of science. Rather, they had brought over into science attitudes deriving from the deism or atheism of semi-clandestine thinkers of the first half of the century. It would, however, be inappropriate to see in this a mere extension of anti-Christian thought into a domain where it had not yet penetrated. The invasion of science by “philosophy” was also to be an irruption of science into this philosophy. The new science would tend to eliminate God in favor of nature: in this sense, it would — favor atheism at the expense of deism, as Voltaire was well aware. On the other hand, it would provide atheism with arguments, if not more profound, at least more rational than those it had possessed thereto. For if the moral parameters leading to atheism could still be set up in the same terms, it was essential to rejuvenate its scientific bases, which were still of Lucretian vintage. * Literally, “Sir Being,” a freethinkers’ prudential code word for God during the Regency. — Ir.

Conclusion to Part III 533 Above all, however, science would not be able to remain content as the servant of atheism after having been the servant of theology. Armed with its own

methods and parameters, it was going to ask precise questions of atheism. The | old Epicurean explanations were going to be put to the test. This confrontation between science and traditional atheism was to provoke a crisis in atheist

thinking. The crisis was not over in 1770, but elements of a solution that would become clear only in the nineteenth century were already appearing. The first requirement of the new scientific thought, then, was to restore to nature its own existence and activity, so that the scientist might study regular relations of phenomena, constant links of cause and effect. The metaphysical debate on the origin of motion does not directly concern us here: it simply proves the importance of philosophical themes in the innovator’s reflections, for science as such did not need to know if motion and attraction were qualities essential to matter. It was sufficient that God not interfere in the world to

modify the overall quantity of motion—as Voltaire thought was the case— and that bodies gravitated all the time and according to the same law. In any case, the simple fact of granting nature the activity that had been taken away from it was a rather important revolution in itself. Science could seal itself off within the study of secondary causes and free itself radically from theology. By the same token, it freed itself, this time for good, from occult qualities: ignorance was temporary; the unknown became a field open to investigation and ceased being the unknowable. First Cause and its mysteries were no longer of concern to science. At the same time, too, the search for final causes and God’s intentions in the physical universe became pointless, since its contents had been produced by nature, not created directly by an Artisan God. Nowhere could the consequences of this revolution have been felt more deeply than in the life sciences, for only there could one see new forms being

born daily. It is understandable that these sciences should have taken on an | exceptional importance in this regard, and that the problem of generation should have become their crucial subtopic. More than any other, save perhaps the theory of the earth, this issue was destined to feel the force of the new ideas. The theory of preexistent germs had made of it the very type of those cases in which the direct action of God had replaced the workings of

secondary causes. Thus, the initial effort of the new science would be to reject the preexistence of germs, to establish the principle that all living forms were the result of epigenesis, which was to say, of secondary causes. The principle

was established a priori, before any observation, and despite the insoluble problems to which it was going to give rise. But, contrary to their predeces-

534 THE PHILOSOPHERS SCIENCE sors, the new scientists would prefer any physical hypothesis whatsoever to

oa metaphysical hypothesis that risked prohibiting all investigation. And because it was a natural fact, subject to the influence of all the natural agents surrounding it, epigenesis allowed and even required the study of everything that could be acting upon it, the study of heredity and environment [milieu]. An immense field of investigation was at that point opened up to biological research. Contrary to the preexistence of germs, epigenesis resolved nothing, but it opened all roads. Thus the new scientists and philosophers made it the point of departure of all their theories and accepted its logical consequence: the study of the facts of heredity and of the modifying action of the milieu. Only from this could transformism emerge. And this movement was

so strong that it spared not even the opponents of the new science: without rejecting preexistent germs, Haller and Bonnet even more were forced to allow much greater importance to the development of these germs, to see in it no longer a simple mechanical enlargement of parts, but a profound and complex transformation that gave more room to the workings of secondary causes and, consequently, allowed the intervention of the natural forces of heredity and environment a certain “latitude.” It was not enough simply to postulate the activity of nature, however; it had to be explained why that activity was not anarchical. Here, too, the life sciences held a privileged place. Indeed, biology served as a touchstone for all philosophies attempting to explain the order of nature without having recourse to a direct, divine preformation. It was easy enough to maintain that the regularity of planetary movement was due to the simple workings of attraction and the laws of motion. It was easier still to show that the distribution of the seas, rivers, and mountains on the surface of the earth revealed no particular design, and that, given the relief, the seas and rivers could not have been distributed in any other fashion. Biology required more. Someone had to explain the regularity of epigenesis and the construction of an infinitely complicated machine. And it was no longer possible to return to Descartes’s daydreams: 75 years of observation had shown that the most simple of living bodies was still far too complex for its formation to be attributed to the general laws of motion. After a timid attempt to call upon universal attraction, Maupertuis had to agree that epigenesis was beyond the powers of mechanism. By adding the “penetrating forces” to the “internal mold,” Buffon thought he had found an explanation. But the “internal mold” was no more than an image, and the “penetrating forces” were unintelligible. Above

Conclusion to Part III 535 all, Buffon no longer dared to believe that a gathering together of inert particles arranged in a certain order was sufficient to bring life into existence. Maupertuis and Buffon remained faithful to the mechanistic image of epigenesis: isolated particles gathered together in order to form a germ, which then needed only to “develop.” But when Maupertuis lent these particles an elementary psychic existence and when Buffon conceived of his “organic molecules,” they were both already renouncing traditional mechanism. Much later, Buffon was to derive his organic molecules from a chemical reaction. In the meantime, he took them for an indispensable primary form of matter, for life could be born only from life. And while Diderot was wondering about the relations between brute and living matter, the young physicians of Montpellier were enthusiastically adopting the theory of organic molecules. For it brought them the notion of an already living primary matter whose laws, consequently, would not be those of brute matter and whose forces would have nothing in common with motion or attraction. But above all, the young physicians were overturning the traditional perspective and were approaching epigenesis from the other end, so to speak. Obsessed by a corpuscularist vision of the world, the mechanists were striving to understand what external force could be directing the corpuscles and making them gather together in the proper order. The laws of motion became powerless, because their determinism did not in practice exclude chance. The physicians, on the contrary, started with the living being, which was live, active, sensitive matter, and a coordinated whole, but coordinated by an order that had nothing of the mechanical in it, instead resting upon the sensitivity of the organs and its relations with the nerve centers. When they wondered how this living being had been formed, the physicians automatically called upon that vital sensitivity that they had seen at work, and conceived of an epigenesis capable of explaining the completed being that they knew. Traditional mechanism thus found itself excluded from this version of epigenesis, whose means were no longer mechanical and whose regularity was no longer explained by the universal and eternal laws of motion acting from outside, but through an internal and specific finality, directing the action of a power proper to living matter: sensitivity.

At this point, epigenesis ceased to be an improbable gathering of molecules

intended to take the place of the preexistent germ. The Montpellier physicians and Diderot, following them in the Réve de d'Alembert, admitted the existence of a germ, which they defined only as a sensitive point and whose _

536 THE PHILOSOPHERS SCIENCE origin they did not specify, but which they took as the embryo of the ner-

, vous system and the agent for the organization of the matter in which it was immersed. Epigenesis had become transformation, a progressive organization of matter by means of a living germ. In this way, independently of the work of Caspar Friedrich Wolff, nascent vitalism allowed a way out of the traditional alternative that opposed an inconceivable mechanistic epigenesis to the supernatural preexistence of the complete germ. This no doubt necessitated a renunciation of clear ideas: it was not at all evident how sensitivity carried out its task. But nothing was to keep future scientists from examining the results and the modalities of its action more closely, from trying to find out what the germ was, and from analyzing down to the smallest details accessible to observation the concatenation of the phenomena progressing from this germ to the completed being. Unlike Ralph Cudworth’s plastic natures, sensitivity was not a sort of independent power acting in matter: it was a quality of living matter. As for investigating whether it was an essential quality only of living matter, or of all matter, or even a gift of God to one or the other, this was a metaphysical question that science did not, in principle, need to be concerned with. Still, the new science did not wish simply to transform, limit, or suppress the role of God in nature in order to restore to nature the activity it had been deprived of. It also wanted, and perhaps more than anything else, to restore _ to man the power to know. Everything that science gave nature, everything it took away from God, it gave to man by wresting it from divine mystery. To understand nature was the goal and justification of its enterprise. And on

this point, it risked losing the support of the philosophy that had helped it take shape. For, whereas the religious science of the Christian naturalists constantly confronted the human mind with the impenetrable barrier of God’s mystery, the traditional skepticism of Epicurean or “libertine” thought overwhelmed man and his puny reason with the inexhaustible diversity of nature.

Diderot, more a philosopher than a scientist, would not be able in the last analysis to free himself from this skepticism, which convinced him of our irremediable ignorance. It was in itself that science had to find reasons for believing in the power of the mind. It was by reaction against the exclusive cult of observation that it was to rehabilitate the theorizing and hypothesizing mentality. Among the scientists in question, no one still believed in innate ideas; everyone was an empiricist; some even seemed ready to believe

that man was merely an animal among the others. But man thought, and this thought, whatever its origin, was enough to ensure him a special place in the universe, in fact if not by right. But the right was of little concern, for it

Conclusion to Part III 537 was a matter of metaphysics or theology, and science was attempting to free itself from the former just as much as from the latter. Man’s place was to be defined by the manner in which he would be able to know the order of the world, and it is understandable that all the scientists in question should have confronted the problem of the conditions of such knowledge. They were unanimous in underlining its relative character. If they were deists, they acknowledged an order in nature willed by a creative Intelligence;

we were unable, they considered, to reach this order except through the doubly distorting glass of our senses and our minds. We knew only our ideas, Needham believed, and we could grasp only relationships: “All is comparison, all is relative, nothing is absolute.” If they were atheists, if they accepted that “all that can be, is,” and that the order of the world was merely a factual

order that related all the “co-possibilities,” they felt all the more comfortable | in asserting that the only order of concern to us was the one that we ourselves introduced into things—thus Buffon in 1749 and Diderot in the article “Encyclopédie.” In this way, the traditional alternative requiring a choice between innate ideas and radical ignorance was temporarily left behind. Man made a science valid for himself alone, but it was no less a science for that reason. Needham in 1750, Buffon in 1749, and Diderot in the /nterprétation de la nature were striving in this fashion to position themselves within the relative.

They were not to be able to remain there. Since, for lack of knowledge about things, we could perceive relationships, Needham immediately went beyond things to describe the play of antithetical principles animating the universe. Never, in truth, entirely convinced by Buffon’s “relativism,” Diderot soon gave in to metaphysical giddiness. When he had believed, on Buffon’s

authority, in the possibility of science, he had seen it as limited rather than relative. Soon he no longer believed in it at all. He no longer saw a means for discovering an order in a universe in which everything that could be was or would be, in which nothing of what was endured, from which nothing was excluded, except the impossible and the contradictory. Universal necessity and the rigorous concatenation of phenomena remained for him a metaphysical and general principle, and he did not see how to isolate certain specific concatenations from the whole, because everything reacted upon everything, _ and because no one could know where to find a beginning or end point in these concatenations. He was too sensitive to the eternal flow of things to take refuge in the “sophism of ephemerality” and to attribute even a temporary value to the present state of nature. On the other hand, and even though he

extended sensitivity to all matter, he remained too faithful to the thought of

538 THE PHILOSOPHERS SCIENCE Epicurus and to Epicurean mechanism to imagine in nature an internal end and a biological determinism, so to speak. Nothing counted for him except eternity and totality. He remained a prisoner of the classical forms of atheism and could not manage to grant man the place in the universe that he would

have liked to. He had no other option, then, but to turn his back on this universe in order to withdraw into another kind of relativism and to seek in physiology, in ethics, or in esthetics —which is to say, in man himself—rea-

sons for not doubting man. | Buffon, however, was following other paths. His 1749 relativism had been founded on his conviction of the disorder of things. In the swarming of ani-

mal species, in which everything possible existed, man had full license to classify beings in the order most convenient for him. Once having adopted this arbitrary order, the naturalist needed only to study the species one after another, and, in fact, Buffon said and repeated that the only true knowledge was provided us by the complete description of each being in particular. Even so, one had to bow to the “sophism of ephemerality” and resist succumbing to metaphysical dizziness at the eternal flow of things. Buffon resisted all the better in that he rejected metaphysics and took on principle things such as he

saw them or thought he saw them, “in the moment of their age.” He saw a living matter distinct from crude matter, species that perpetuated themselves, and human thought capable of knowing and unique in kind. These give the

elements an order, a factual and no doubt temporary order, but a real one that could serve as the basis for the scientist’s reflections.

This, then, was where Buffon’s procedure parted company with that of the observational naturalist, who stayed within the description of forms, and with that of the philosopher obsessed by eternal transformations. For Buffon, as for Maupertuis, forms were not an inexplicable given, but the result of a concatenation of causes and effects that we had to attempt to reconstruct by starting with the present and working our way back as far as possible into the past, which is to say, as far as comparable phenomena allowed us to assume a single cause. Metaphysically, this procedure was untenable, for it claimed to isolate a linkage of facts in a universe in which everything was re-

| acting with everything. In practice, it allowed complete knowledge, because it explained things. In certain instances, when a single event was at issue, it provided only an unverifiable hypothesis— for example, the force of a comet striking the sun as a cause of the formation and movement of the planets. In other instances, the hypothesis was susceptible to experimental verification: one could not prove that the matter of planets was the same as that of the sun

Conclusion to Part III 539

but one should be able to prove, through cross-breeding, that two animals were simply varieties of the same species. In every case, the benefits of science

were evident: when the physical cause of a phenomenon had been discovered, the phenomenon had been explained and understood to the extent that it could be by science; when several phenomena had been explained through a single cause, the diversity of things ceased being anarchical and began to acquire order; finally, one could determine the laws regulating the passage from cause to effect. By applying this method to animal forms, Buffon reduced the welter of quadrupeds to a small number of original species and showed how

domestication and climate, acting upon the original type, had produced the different varieties, which thus found themselves “explained” and classified into truly natural families. But he was to attempt to go too far and to explain in the same fashion what he had accepted in 1749 as simple factual givens. Human thought and its superiority, then, found their explanation through language and social existence, which in turn were explained by way of the slow pace of man’s physiological growth. Living organic molecules were explained by way of the action of heat on “oily and ductile” matters. The combinations of the molecules, which gave rise to animal and vegetable species, were very precisely regulated by climate. In this way, all the current forms of things—organic molecules, animal species, human thought—resulted from the action of natural causes upon older forms. This action of natural causes was regulated by rigorous laws, the existence of which Buffon most often simply afhrmed, without managing to formulate them, but which he would always consider to be universal, eternal, and, properly speaking, constitutive of the order of the world. In this fashion, Buffon’s science succeeded in discovering an order in the universe above and beyond the jumble of forms and in positing eternal laws that regulated the course of things instead of being subject to them. At the same time, moreover, science won out over eternity. For by working back into

the past through a chain of effects and causes, it cut out of the eternal flow of things, so to speak, a certain duration of time identified by an irreversible sequence of phenomena, that is, a history, of which the present state of nature was the result. Through the application of this method to the life sciences, Maupertuis, too, had arrived at the idea of a history of living nature,

at the hypothesis of a generalized transformism. It would seem that Buffon | understood this possibility for science only late in his career. In 1749, he had

indeed set a beginning for the solar system, but the planets, once formed, entered into eternity: they did not change, they had no history. It was only in

540 THE PHILOSOPHERS SCIENCE 1765 that, thanks to the theory of the gradual cooling off of the planets, Buffon was able to conceive of a general history of nature on earth, subsequently described in the Epoques de la nature. From the formation of our globe until its present state, phenomena were linked irreversibly through the action of eternal laws. The “consolidation” of the earth, the formation of land surfaces, the birth of life, the distribution of animals over the continents, nothing was missing — except for the transformism towards which everything seemed to be pointing, but that Buffon would never accept, all the while providing every possible reason for believing in it. Moreover, this history of our earth and our nature was applied by Buffon, through analogy embracing the past, present, and future, to the other planets of the solar system, to all other planets that had circulated, circulated, or would circulate around other stars. Eternity was

no longer an ocean in which the mind drowned: it was no longer anything other than a series of like histories, since like laws everywhere regulated the activity of like matter. Buffon thus agreed, in his fashion, with Maupertuis. Needham, too, had deployed the action of his antithetical principles in time and had conceived a history of nature beginning on the day of Creation. Once nature had regained its rights, everything had to take place in time. The vitalists’ epigenesis was a lengthy process of formation completely different from the instantaneous assembling of molecules that Buffon still fancied. From every direction, science was leading towards history. Bonnet, Needham, and many other geologists were, like Buffon, attributing a lengthy past to our globe. For no particular reason, Jean-Baptiste-René Robinet spread out the development of preexis-

| tent germs so as to project the chain of beings into time, thus contributing to the diffusion of the idea, already expressed by Needham, that the simplest beings had been the first to appear, and that the history of life was the history of an increasing complexity of living forms. For both Christians and deists, this intrusion of history into the sciences of nature implied a new way of interpreting Genesis, or rather a return to abandoned interpretations and a new manner of conceiving of Creation. This was a profound revolution, which was to give rise to impassioned resistance all through the nineteenth century and has not yet entirely triumphed today within Christianity. For traditional atheism, the difficulties were no less great. A history of nature seemed impossible to reconcile with the necessary eternity of matter. More or less obscurely, the order of a historical development seemed to imply a goal, which atheism rejected. One can understand that Diderot, imbued with Epicurean atheism and haunted by the vision of an eternal universe in motion, never accepted a

Conclusion to Part IIT 541 historical conception of nature or understood the advantage of a truly transformist theory. Still, there were many ways of conceiving of this history of nature, and especially of conceiving of its modalities. For Robinet, it was a successive realization of God’s designs, established on the first day in the preexistent germs. Nothing in nature demanded this particular order rather than another, and one could not truly speak of a history. For Buffon, who remained a mechanist, the history of life resulted from the necessary application of physical forces to living matter. He does not seem to have been particularly attentive to the manner in which the living being reacted to the impulsion of these external forces. He did not assume, in any case, an original activity of any sort, any spontaneity in the reaction of the living organism: a large volume of grass expanded the belly of the ox just as water polished a pebble. Still, he had accepted that a modification of any sort in one part of the body had to have repercussions for the entire body; but he did not attempt to explain the fact, and did not grant living matter any autonomous principle of activity. For Needham, on the contrary, matter contained in itself the principles of its development, which merely obeyed an internal necessity whose rules God had set down. But the universal character of those principles made it difficult to conceive of their role in generation or in the adaptation of living beings. Finally, it was the vitalists of Montpellier who were to provide the best explanation of a history of life, even though they were themselves scarcely concerned with it: “sensitivity,” which would soon become the “vital principle,” an internal principal of action in living matter, capable of reacting opportunely and with choice to external stimuli, and perhaps capable of modifying the very organization of the animal according to the requirements of its vital needs. Diderot, under their influence, would write that “needs produce organs.” It was not he, however, but Lamarck who would draw the consequences of this and use the resources of “sensitivity” as an instrument of evolution. Here, too, Diderot refused to abandon Epicurean mechanism. Along with d’Holbach, he remained faithful to the notion of a universe-machine

_ without accepting any other mechanism than unknowable determinism and the elimination of nonviable beings.

LIVING NATURE, in1740, had been a machine set up by God, passive and immutable. By 1770, despite still lively resistance, scientists and thinkers were beginning to see in it an autonomous force, capable of an invention of © sorts, and one that, through its own powers, was able to travel along the con-

542 THE PHILOSOPHERS SCIENCE tinuous line of an irreversible history. Man had escaped eternity, immutable fixity, and hopeless chaos, but he had still not achieved the knowledge of nature that he had hoped would be his prize. The first reformers, Maupertuis and Buffon, had attempted to found a new rationalism. It was in the name of man, his reason, and his right to understand the world that they had rebelled against the philosophy of the preceding age. But they had thought they could base this new rationalism on traditional mechanism, an enterprise doomed to failure. Buffon set up the framework of a history of nature and voiced the enthusiasm of a scientist who had been able to understand the world. But no one around him believed in his theory of generation any more, and if, along

with him, they accepted the action of the environment on animal forms, they had recourse to vitalist explanations to account for it. The new science had succeeded in removing the mystery of God from nature, but it had not been able to explain life rationally. Traditional mechanism was threatened with collapse, and the progress of vitalism would soon complete its demolition. With it, a whole world of intellectual habits and religious or philosophic attitudes was in danger of disappearing. That world would survive, however, and would hasten to attach itself in the course of the nineteenth century to a new mechanism in which chemistry replaced geometry. Nonetheless, in the interregnum, transformism had the time to find a complete formulation. The notion of a history of nature was no longer denied. Historical materialism had been made possible. The clandestine philosophy of the first half of the century, from which the new scientific philosophy had taken its impetus, had embodied nothing of

, this. Each in his own way, and filling in the gaps for one another, the naturalists, biologists, and physicians contemporary with the Encyclopédie, Maupertuis and Needham, Buffon and the doctors of Montpellier, thus supplied our intellectual universe with some of its fundamental characteristics.

Epilogue

THE QUESTION of animal reproduction, whose history we have followed over a century and a half, provides a particularly faithful mirror of the intellectual life of the seventeenth and eighteenth centuries. Philosophic and religious concerns came to the forefront in this area more powerfully than elsewhere, for the question inevitably raised all the problems of life, of the power of nature, of the order of the universe, and of knowledge. No question was harder to approach without prejudice, and none was better suited to illustrate the dominant philosophies. Conversely, however, contemporary biological experimentation was absolutely original, and this originality could not have been more keenly felt than in a period of triumphant mechanism. The study of living matter inevitably suggests the idea of an autonomous, hard-to-define force. Mechanistic analyses always seem to sidestep the essential, which is life. Man feels powerless before this universe, of which nonetheless his body is a part. For man conceives clearly only what he does, and life remains outside his powers. Through its way of acting, it is foreign to man: it is internal spontaneity, it acts upon itself, whereas man remains outside of its work. Aristotle compared the male seed to a craftsman who conferred form on matter without being in the matter. And this all-too-human image expressed a profound need, that of reducing life to a known and intelligible phenomenon. In a different fashion, the Galenic “faculties,” the “souls,” the “archei,” the “plastic natures,” all those powers dispatched by God to work inside living matter, expressed the same need. It little mattered that the action of these divine agencies was unknowable, that it was an “occult quality.” It was none-

544 Epilogue theless conceivable, for these forces working in matter were not matter. In _ their way, they worked like man, or God made use of them to work like man. And better the mystery of God, which was reassuring, than the mystery of life, which was frightening. The mystery of atoms and of laws of motion, too complex to be truly accessible, is less reassuring than the divine mystery, but it nonetheless offers the mind a conceivable image of nature. Life with its secret forces, its obscure _stubbornness, its slow and blind but infallible striving, always risks being an evil power, just as the flesh is a source of passion and of sin in us. For perhaps a very long time, man has been fighting against life, in himself through asceticism and outside of himself through knowledge. When he gives up on mastering life and on wresting himself away from her grasp, or when he gives in to the headiness of vitalism, man always risks having the feeling of an abdication of his mind, a blissful or resigned defeat, a renunciation and an abandonment to the forces of nature, which will perhaps bring him either power or rest, but in self-oblivion. This was the way the confrontation between man and living nature presented itself in the seventeenth and eighteenth centuries. At one point, man claimed to dominate life by denying its originality, by subjecting it to the blueprints of his reason, by analyzing its processes in order to reduce them to simple mechanisms, by imitating its technology, by acting violently on it. At another point, conversely, he abased himself before life and gave up on understanding it, not because he believed that its modalities were foreign to those of human thought, but only because the relationships among things were too complex, the rationality of the world was inaccessible, and human reason was too limited. Ignorance, therefore, remained relative, and man reserved the power to act upon nature within the restricted circle of his knowledge. Finally, at still another point, man saw life as a power absolutely alien to his thought, and one that arrived at its ends through irrational means. Science could observe the operations of nature. It could at times facilitate or use them, but it could not imitate them. In any case, it was no longer by way of science and discursive thought that man could hope to attain the real: it was imagination, intuition, or instinct, it was everything connected to life in him that would allow him to join up with the forces of life, to know them, and at times to tap into them, albeit without understanding them. Thus, rationalism affirmed the rationality of life and made claims to reach it, skepticism assumed it while giving up on knowing it, and vitalism denied it or at least considered it foreign to our intellectual categories.

Epilogue 545 In this confrontation between man and nature, God intruded most often as a third party. To the rationalist, He brought the certainty that his efforts were not in vain, that human reason, a reflection of the creative intelligence, could understand a rational universe. He justified and sanctified the effort of the human mind to know and master Creation. But God could also abandon man’s camp and pass over, so to speak, to the side of nature, which then became awesome and incomprehensible, because it was the work of divine wisdom, which went infinitely beyond man. Reason bowed down before the wonders of life, which were marks of omnipotence. Still, for the rationalist, as for the skeptic, God was external to His Creation, like the artisan to his work, and this was what allowed man at least to imagine the rationality of the world. For the vitalist, on the contrary, there was the danger of God becoming the soul of nature. Reason could scarcely conceive of Him. It was enthusiastic communion with the forces of nature that would allow union with the divine life. —

Man can know, adore, or participate in God, but these three stances are , not necessarily mutually exclusive, for they may be situated at different levels

of the soul or the mind. Still, if one of them tends to predominate on the plane of knowledge, according to the fashion in which man conceives of his relations with nature, the entire attitude of man vis-a-vis God is likely to be affected. Besides, merely to define knowing, adoring, and participating in God epistemologically is to schematicize and impoverish these stances. In reality, they involve all the intellectual and affective aspects of human life—science, art, morality, and religion — because each of them assumes a complete image

of the human condition, with all that this implies of hope and fear, confidence or disquiet, blossoming or enclosure. Nature does not change: it is man who changes, who defines himself with respect to it, and who expresses the multiple tendencies of his being, buoyed by historical crises, currents of thought, and individual temperaments.

It would be satisfying to the mind to be able to impose an order anda chronological progression on these philosophic and scientific attitudes. Unfortunately, reality is not so docile. It is generally accepted that the first half of the seventeenth century saw the old Aristotelian thought succumb under the blows of the new science. As noted, however, at least as far as the subject of this study is concerned, this doomed philosophy that took so long in dying was already highly composite and not even very Aristotelian. No doubt one could still find irreproachable defenders of Aristotle’s rationalism after 1620. Cesare Cremonini in Padua, for one, imperturbably saw in nature the play of

546 Epilogue form and matter. The last embers of Averroéism still glowed. But elsewhere and long since, Aristotelianism had been wrecked from within by Platonism and by Galen. Even before 1550, Jean Fernel was having “forms” descend from the heaven of ideas and superimposing an occult metaphysics onto elementary physics. At the end of the sixteenth century, Fabrizio d’Acquapendente was in practice replacing the internal action of the “form” with the interfer-

ence of “faculties,” skilled hands sent by God to work on matter. Fernel and Fabrizio thought of themselves as Aristotelians. In fact, they both abjured rationalism and confided to God responsibility for forming beings and acting continuously in Creation through the mediation of “hidden causes” or “formative faculties.” No doubt God intruded only by interposition, which allowed one to distinguish the natural from the miraculous and to leave nature a certain margin of activity: the “faculties” could commit “errors,” and God was not responsible for teratisms, except for those that he chose to use as signs.

This limited autonomy granted to nature does not, however, indicate an intention to carve out a place for rational understanding. It reveals, rather, a vitalist temptation, for which Paracelsus was largely responsible—a temptation Giordano Bruno was unable to master as the source of a new rationalism. This nature was without order; blind matter resisted the action of the “faculties.” There was nothing there that reason could grasp. In every sense, Aristotelianism was good and dead. The notions of form, potentiality, and actuality, which had regulated the processes of nature, had become unintelligible to the very people who made the schools resound with the terms. The old rationalism had not succumbed to the assaults of a modern mode of thought: it had decomposed from within. And the end point of this decomposition was the great intellectual crisis of the beginning of the seventeenth century, when the “physicists” were torn between God and nature, each as incomprehensible to them as the other. Henceforth, nothing was explainable, “there being no philosopher who can say why a horse begets a colt rather than a calf.” The new science was Descartes and his mathematical rationalism. In nature there were only matter, shapes, and motion. Matter was inert and passive, and motion, introduced by God, obeyed laws that reason could know. No mystery, divine or natural, opposed man’s gaze in the created universe. God no longer intervened in it except to preserve its existence. Things, and even living things, were, or at least might have been, the simple result of the laws of motion. God simultaneously guaranteed the rationality of the world and the worth of human reason. As we have seen, however, this triumphant

Epilogue 547 rationalism scarcely penetrated into biology, where the efforts of the new scientific spirit took more modest forms. For philosophically minded physicians who wanted to climb out of the chaos into which the old science had sunk,

it was first of all a question of eliminating the temptation of vitalism. They therefore gradually adopted the notion of a passive matter, incapable of organizing on its own, of acting on its own, and of resisting the forces of organization. Whether vegetative or sensitive, “souls” tended to disappear, for they expressed precisely such spontaneous activity by living matter. It was not yet a question of granting the laws of motion the power to organize and to vivify matter, however. To explain life, it was more necessary than

ever to have recourse to a soul, albeit a spiritual soul, the only kind that did not risk reintroducing vitalism. J. B. van Helmont began by reinterpreting all of Paracelsus’s thinking in this sense. Thomas Feyens showed that the organization of the fetus was directed by the spiritual and immortal soul of man. In striving to prove that all souls, even those of plants, were spiritual principles, Daniel Sennert arrived at a clear notion of life: a spiritual soul, a mind, elaborated passive matter. If God created each soul individually, however, living nature remained directly dependent on the Creator, and, as Sennert puts it, there was no true generation. There were no longer even laws of nature: everything depended upon the divine will. Helmont was delighted with this, but many biologists felt, in their fashion, the need to safeguard the autonomy of nature and the regularity of its laws. It was a question of doing for life what Descartes had done for motion: put God at the origin, but let Him not interfere thereafter. Sennert therefore accepted that souls had begotten one another, since the first created souls. By confiding to the soul of the adult responsibility for entirely constructing the body of the begotten being in the form of a germ, the theory of preformation not only allowed one to avoid the insoluble problems of the ensoulment [animation] of the embryo, it also more closely related beings to one another and made of them a chain uninterrupted since Creation. But what good was it to have reduced God’s interference to the initial Creation, to have brought generation into the order of nature, if the agent of that generation remained a soul, whose means of acting on matter were incomprehensible?

By transforming concatenations of souls into concatenations of atoms, Pierre Gassendi obeyed the general tendency of the century to see in nature only matter and motion. But not being a rationalist after the manner of Descartes, Gassendi did not think that the general and universal laws of motion,

548 Epilogue acting upon inert matter, had the power to form such or such an animal. The animating motion had to be regulated in a more precise and specific a manner. This was the function of the systems of atoms that, passing from one being to another, determined the movement suited to the formation and maintenance of each species. God had not remained content simply with creating matter and motion. From the outset, he had organized this matter into as many systems of atoms as there were living species. And in order to understand spontaneous generation, one had to accept that God had created complete germs, which then needed only to develop. In fact, if one excludes Descartes’s attempts, biological mechanism never

progressed further along the path of rationalism. Virtually no one really thought he was able to explain life and the formation of beings by way of the laws of motion alone. Cartesian rationalism faced a coalition that united biological experimentation, which was naturally quite unfavorable to mechanism; the skepticism of the “libertines” [1.e., freethinkers], who were not very disposed to grant so much power to human reason; and the “skepticism” of the Augustinians, who were not very tempted to grant nature an “efficacy” that belonged to God and to free science from the guiding hand of theology.

Whether they invoked spiritual principles or a more or less complete material preordering, seventeenth-century biologists left responsibility for life and living forms either to God, whether directly or indirectly, or to the mysterlous primordia rerum [origins of things]. And the most truly mechanistic were precisely those who, by eliminating the action of spiritual principles, had living beings come most directly from the hands of the Creator. Mechanism thus played the Augustinian game. The success of preexistent germs is not only explicable because people simultaneously found in them Lucretius’s primordia rerum, the “seminal reasons” of Saint Augustine, and the “seeds of things” of modern [i.e., Paracelsian] chemical medicine. It is above all explainable because biological mechanism almost necessarily assumed a divine preordering. Still, preexistent germs conferred on this preordering a rigor that was not indispensable. The systems of atoms imagined by Gassendi were perhaps of divine origin; but by transmitting a particular type of motion, they served as organizing germs and were not already organized themselves in the form of an entire and complete animal. There was still room for epigenesis.

It was the Augustinian theocentrism of the end of the seventeenth century that demanded preexistent germs and that ensured the success of a science in which God played an increasingly important role. Seventeenth-century biology was, then, much more “skeptical,” in our

Epilogue 549 sense of the word, than “rationalist.” It left responsibility for directing the formation of living beings to the free and unknowable activity of God. This was the price it had to pay for remaining mechanistic. Throughout the entire first half of the eighteenth century, skepticism steadily increased, and the mechanistic rationality of the living universe, still professed as a principle, became increasingly inaccessible. With Buffon, traditional mechanism, filled out by Newtonian attraction, once again attempted a rationalistic explanation of life. Again, it was a failure. At the end of the eighteenth century, the prevailing vitalism was opposed only by the atheistic skepticism of Diderot and the religious skepticism of Bonnet and Haller. Both postulated a rigorous order in nature, whether deriving from things themselves or from God, and neither believed human reason capable of attaining and truly explaining that order. For a new rationalization of the living world, either a new variety of mechanism that would seek to analyze life through the study of chemical phenomena or a new rationalism, founded on the very history of nature, that would attempt to rationalize life through the laws of its own movement was required. The life sciences thus resisted mechanistic rationalism, whether the me-

chanics of it were Cartesian or Newtonian. Born of physics, mathematics, and astronomy, this rationalism was far less easy to apply to living nature than Aristotelian rationalism. Nonetheless, there were differing degrees of re-

sistance involved. Depending upon the period, biology displayed more or | less openness, if not to complete rationalism, at least to the possibilities of partial explanation offered by mechanism. Once past the time of protracted mistrust, when philosophers alone attempted to mechanize life, biologists adopted the new science, all the more freely perhaps in that the theory of preexistent germs eliminated a serious objection. But the flowering of anatomical studies, clearly favorable to a mechanistic physiology, was not to last beyond the end of the seventeenth century. The success of natural history, especially entomology, at the expense of anatomy was too complete and too rapid not to augur a new phase in the zeitgeist, and with a retreat by mechanism, a decline in the partial rationality that it had introduced into the life sciences. No doubt there was to be a renaissance of biological mechanism with Haller, but this neomechanism founded on irritability was as different from the old as Newtonian mechanism was from that of Descartes. In both cases (and Haller himself noted the analogy), it was necessary to accept an unexplainable force prior to any explanation. And this, too, indicated a retreat by rationalism. Thus, the first conclusion to be drawn from this study is that if one under-

550 Epilogue stands by “rationalism” a philosophy granting human reason the power truly to understand the world, the biological thought of the eighteenth century, setting aside Buffon, was not rationalistic. Before giving in to vitalism, it had asserted that nature was mechanistic and that its mechanism was inacces-

sible. From Fontenelle to Diderot, from Réaumur to Haller, the biological thought of the century was skeptical and allowed reason only a limited function in critique and analysis, never granting it any hope of arriving at an explanation of forms, either because those forms resulted from an inextricable jumble of causes or because they proceeded directly from the divine will. The

skepticism could be Christian, in the manner of Réaumur or Haller, deistic in the manner of Fontenelle, deistic again, although in a different way, in the manner of Voltaire, or, finally, atheistic in the manner of Diderot. But it was always a form of skepticism. And this ambiguity in the skeptical stance, which was capable of being either religious or naturalistic and made its presence felt throughout the seventeenth and eighteenth centuries, merits our attention too. It was the skepticism that united Pascal and Gassendi against Descartes, Arnauld and Bayle against Malebranche, Réaumur and Voltaire against Buffon. Unquestionably, all the necessary distinctions must not be forgotten. But the same suspicion of man, the same admiration for the wealth and diversity of nature, the same submission to the facts, and the same search for new, unexpected, diverse, and at times wondrous data were always present. If the eighteenth century was, especially in its first half, the age of the natural sciences, of observation, and, as has been said, “the age of curiosity,” it was because it was an age of skepticism. Réaumur's insects came and took their place behind Montaigne’s cannibals in the long succession of oddities that obliged us to acknowledge our inadequacy. “Truth on this side of the Pyrenees, falsehood on the other”: how many borders in living nature, more impassable than the Pyrenees, and separating more different worlds! How improbable the analogies that we were attempting to establish seemed, how precarious our most firmly grounded reasoning was! And how unjustified the claims of a Descartes or a Buffon, who wanted to fuse everything in the crucible of their minds and reduce the infinite diversity of nature and the infinite wisdom of God to the dimensions of human reason!

For the biologist, and still more for the naturalist, skepticism thus appeared as a required form of humility, as a legitimate mistrust of one’s own strength, and rationalism took on the appearance of a thirst for power and of self-assertion. Such clear psychological positions reveal underlying tendencies in individuals and an age that could not help manifesting themselves in other

Epilogue 551 areas. Beginning with the most direct and immediate relationships, we may assume the work of a scientist, even down to his manner of writing, to be likely in its entirety to bear the mark of an intellectual choice that expresses his character. In the second half of the eighteenth century, Réaumur was at times reproached with being dull and diffuse. Now, certain pages in his correspondence prove that he was, on the contrary, capable of coming up with lively and pungent strokes. But was it not the duty of the observational scientist to efface his presence, to include the greatest possible number of details in his account, and never to act as a screen between the reader and nature? Unconsciously, no doubt, Réaumur adopted a different style in his natural history from that of his letters or his prefaces. Conversely, Buffon’s style of writing reveals a mind little inclined to take second place to its object and less concerned with setting forth data than with communicating its personal convictions. In a solidly timbered sentence, the main clause is shored up with subordinate clauses supplying arguments or ruling out objections. The unity of the sentence or period assembles the secondary ideas around a central idea. It is easy to understand why all his contemporaries granted Buffon the merit of eloquence, which is the art of persuasion. No scientist had ever possessed more powerfully than he the style of his individual genius or of his scientific character. None had sought less to efface himself, or at least to efface the signs of his thought processes. Other more complex relationships appear in the philosophical writers who participated in the scientific life of their time. Fontenelle, Voltaire, and Diderot are cases in point. No doubt one needs to exercise prudence, avoid risky

comparisons, and be careful not to introduce an artificial unity into a living system of thought. One may at least assume, however, that the scientific positions adopted by philosopher/writers reveal their characters by the same title as their style or their literary opinions. It is known that Fontenelle used the argument of science in the quarrel of the ancients and the moderns. But on a deeper level, Fontenelle’s skepticism was not just a renunciation of the grand hopes of Cartesian rationalism. It took moral and literary forms as well. Part 1 of the Lettres galantes (letter 49), which shows a band of young people joyously preparing for a costume ball and then at the last moment opting against the festivity and the disguises, works as an astonishing symbol of Fontenelle’s

renunciation of the heroic ideal of the preceding age. It was no good trying to disguise oneself as Amadis, wanting to dress up “like those old-time madmen who traveled afar to right wrongs, and like those scrupulous damsels who rode on the crupper behind them and followed them in their adven-

552 Epilogue tures.” Man was not a hero out of the old romances. The excitement soon abated, leaving in its wake only disenchantment. One might as well exercise lucidity and give up earlier. And Fontenelle ushered in a literature of pure amusement, which refused to be the bearer or creator of moral values, no — longer even managed to produce a full-blown work, and frittered itself away in letters and tiny dialogues. The artist could no longer get a grasp on the real in order to reconstruct it in a work whose meaning and structure responded to an inner call. Fontenelle’s very style, with the “adornments” that would so irritate Voltaire, its ingenious comparisons and strokes of wit, no longer had as its mission the expression of deep emotions or a vision of the world, but rather to decorate and make “acceptable” a disappointing reality. To the ex-

tent that classicism had sought to order the world around man, everything in Fontenelle rejected classicism, and his scientific skepticism was simply one form this rejection took. The Voltairean universe was vaster than that of Fontenelle, but one might well maintain that no image could better express his vision of the world than that of the solar system. God was at the center of His creation, like the Sun: everything came from Him, everything had to tend towards Him. The unity of the universe derived from the uniqueness of its center, and Voltaire could, thanks to this, remain faithful to classical universalism. But the diversity of human races and the unity of “natural law” were both safeguarded, for both

came from God. Deism was thus universal and could find support in the consensus omnium. By the same token, both the classical notion of an esthetic absolute and the rigorous requirements of a taste that transcended geographical and historical relativity were justified. In society and in the state, everything radiates from the king, the center and soul of the nation. Voltaire never lost his admiration for the Sun King, Louis XIV, who reigned over his people like God over nature. For “whoever thinks and . . . has taste,” the history of humanity boiled down to the history of a handful of civilizations born around “enlightened” monarchs. Voltaire himself had for a long time been incapable of resisting the attraction of sovereigns: Louis XV, Stanislas,” Frederick [the Great]. Later he was to distance himself from them, but he would never give up attempting to influence them, for he would always conceive of society as a hierarchy in which power and enlightenment emanated from the prince. In a universe in which everything came from the center, however, and where the laws of nature were seen primarily as marks of the creator’s wisdom, * Stanislas Leszczinski, whose court was at Nancy, was titular king of Poland and Louis XV’s fatherin-law. — Tr.

Epilogue 553 what was at the periphery was without interest, passive and derisory. Motion,

life, sensitivity, thought, inert or living forms, all resulted from the direct and , continual action of God. Matter could do nothing on its own: “Mens agitat molem.”* Nature was no more than a shadow play, a magic-lantern spectacle. And man, who foolishly thought himself the king of Creation, merely heaped the ridiculous onto the insignificant. Voltaire’s skepticism then took its full revenge on those pretentious “insects,” those “marionettes that Brioché directs and moves without their realizing it.” * Voltaire’s philosophical tales admirably express this vision of man, with their diagrammatically gestured characters scurrying about, stripping their human poses of all their borrowed ornaments, of the noble draperies in which they are rigged out, while the style of the narration, reducing all theology to some absurd rite or creating unforeseen logical connections, cruelly underscores the weakness of our reasoning and the contradictoriness of our choices. As powerless in science as in the rest, man had only one duty: to confess his ignorance. And the people had only one duty: to obey. For nothing came from the people, just as nothing could be born from matter. Here, too, “Mens agitat molem.” No one was less democratic than Voltaire, who nonetheless

knew better than anyone how to stir up public opinion. No one believed more firmly than he in the irresistible movement of history: it was great men and chance that ruled the course of human events. Nonetheless, all was not always perfect in so well ordered a universe. Voltaire did not live in the time of the Sun King, but in that of Louis XV and of “the king’s secret.” God's secret was no less impenetrable, and “there is a horrible amount of evil on earth.” Here again, the tales depict a universe ruled by favor and disgrace, in which the most highly regarded favorite at court must have his horses saddled at all times, ready for immediate flight. There was no hope of legality, no possible recourse to human justice. As for God’s justice, who knew it? Having become in his turn a solitary and luminous star, having become “King Voltaire,” the philosopher attempted to act for the good of mankind and to inspire the struggle against /znfame [the Catholic Church]. But never, even in the darkest hours of discouragement, would he renounce his Sun God, who formed and animated all that lived on this earth: “In eo vivimus, et movemur, et sumus.”?! Diderot presents a contrast to Voltaire in every respect. It would seem that he did not adopt universal attraction immediately, and that when he did accept it, he made from it more of a linkage among the parts of the universe * “The mind moves the mass,” or “Mind over matter.” — Tr. + Pierre Dattelin, called Brioché, 1567-1671, was a renowned puppeteer. — Tr.

554 Epilogue than an instrument for the hierarchization of the world. As long as he was a deist, he conceived of God according to the demands of his heart. For him, order and thought rose out of the mass of things: order was inscribed in matter and its motion, and thought emerged from universal sensitivity. Diametrically opposed to Voltaire and his Platonic imagination, Diderot rediscovered an Aristotelian vision of the world, and one no doubt less intellectual than Aristotle’s. For him, forms really rose out of matter. Politically, without being a revolutionary, Diderot recognized the people’s right to self-government. Despite his relationship with Catherine the Great, he strongly rejected the theory of enlightened despotism and reproached Helvétius for having considered men as “a herd whose demands one disdains, on the grounds that one is leading it into green pastures.” Nothing could have been more opposed to his

, thought than the “Mens agitat molem” repeated time and again by Voltaire. But the great problem was the confrontation between man and this mass that moved on its own. In the area of knowledge, art, and morality, Diderot kept finding this same difficulty in man’s relationship with nature, and his hesitations were the same: must man remain subject to nature, or must he distinguish himself from it and attempt to impose his law on it? From the standpoint of epistemology, Diderot ended up accepting man’s defeat and inevitable ignorance. In the area of art, on the contrary, Diderot, who in the Neveu de Rameau preached absolute submission to nature, without practicing it, seems to have accepted in his later Sa/ons—with respect to the painter JeanBaptiste Siméon Chardin, for example —that the artist had the right and even a duty to impose his vision of the world and to build his work according to his personal requirements. His dramatic theory and the Paradoxe sur le comédien [Paradox of the actor; 1770-73] reflect the same hesitations, and the opposition between the head and the “diaphragm” is only one particular aspect of the dilemma. For nature is in man just as much as outside of him, and if Diderot as a writer scarcely felt inclined to subject himself to the real, seizing hold of it rather for the purpose of re-creation, did he know whether he was the master or the slave of his inspiration as a creative artist? As for morality, which the Lettre sur les aveugles had made subject to the data of the senses, it became more and more a fact of human existence, with no equivalent in nature. Despite the charms of the “natural” life lived on Tahiti, the Supplément au voyage de Bougainville ends with the not very “naturist” conclusion that one must “adopt the gown of the land to which one goes, and observe the gown of the land one is in.” The Essaz sur les régnes de Claude et de Néron, which post-

Epilogue 555 pones into a distant future the possibility of knowing nature, simultaneously sketches out an ideal of moderate stoicism in which the wise man counts

more upon his own powers than on the virtuous impulsions of nature. Immersed in a universe that he did not understand, man had to make himself the subject of his study, and the purpose of physiology was to allow him to know himself better and perhaps at last to understand why he was different from the rest of nature: “I am a man, and need causes relevant to man.” Scientific knowledge thus claimed its place in the thinking of the philosopher/writers, acting upon their philosophy and at the same time expressing it in its own way. In the same fashion, it necessarily gave expression to the thought of a period, and it has to be possible to find the links between the sciences and the other aspects of the intellectual and artistic activity of a given

age. Here more than elsewhere, one must exercise prudence, avoid hasty analogies, and take note right away that one must not expect to find perfect synchronisms between the appearance of like tendencies in different areas. Often, it seems as if the sensibility of writers gave them a presentiment, so to speak, of the mental evolution to which science would subsequently testify. Cartesianism was in the process of conquering the scientific world, and Fontenelle was not yet a member of the Académie des sciences when the Lettres galantes deliberately broke with the ideal of the “Age of Louis XIV.” But Fontenelle was not alone. La Bruyére, who looked down on Fontenelle, no doubt did not see that he was far closer to him than to Racine, that like him he was abjuring the creation of complete works in order to produce a “natural history’ of minds, to write an amorphous book that could expand from edition to edition because it was not structured, that more and more paid homage to the curious and the bizarre, and that sought to please only through the pleasure provided by the detail. The vogue for “true” novels, memoirs, and letters bears witness to readers’ taste for real facts, and to their lack of interest in the art of the novelist. Fairy tales and the Arabian Nights in their own way satisfied this taste for the brute fact, the exotic or wondrous detail, everything that wrested man away from himself in order to send him into a different universe for his diversion. Interminable narratives, works never finished because nothing required them to be except the author’s or reader’s exhaustion: the Diable boiteux, the endless Gil Blas, derive from this way of writing. But the clearest instance is no doubt that of Pierre Marivaux. Never has a writer more closely resembled a naturalist or been more indentured to his object than he (especially so in his novels), more attentive to describe it in its slightest details, less |

556 Epilogue concerned to shorten and structure. There is nothing surprising in the fact that the Vie de Marianne and the Paysan parvenu were never finished. The volumes kept coming, like those of the Mémoires pour servir a Uhistoire des insectes: could one claim ever to have exhausted nature? “I do not know how

to create,” said Marivaux, and this sentence might define him. He always remained the “French Spectator,” * the observer of those strange animals called men. That he was an admirable writer changed nothing: his very style, his long and sinuous sentences, perfectly matched the nuances of infinitely subtle feelings that they were charged with expressing, and that his characters were the first ones to be surprised at discovering within themselves. No novelist more deserved to be Réaumur’s contemporary. For the artist and the scientist could have the same attitudes vis-a-vis reality: submit to it, or recreate it.

The history of the feeling for nature in the eighteenth century shows | another type of relationship between science and literature. For man to feel moved before nature, he must feel in it a friendly and powerful presence, a force that protects while transcending him. The rustic is most often ignorant of this feeling, because he spends his life doing battle with nature. The city-dweller does battle with men and their wickedness. Thus, nature brings him peace, the image of a simple and easy happiness, and something like the purity and felicity of the Lost Paradise. He who lives in nature seems to him far away from evil and close to God, close to the heavenly Father who clothes the lilies of the field and feeds the birds of the air. It is easy to understand that the feeling for nature should have been born in the eighteenth century among the English scientists who at each step discovered in Creation signs of divine beneficence. On the continent, from the abbé Pluche to Bernardin de Saint-Pierre, by way of the geologist Elie Bertrand, Haller, who was as much a poet as a man of science, and naturally Jean-Jacques Rousseau, the life sciences, the adoration of Providence, and the feeling for nature joined forces as if by necessity. And it is easy to understand as well that, among the great writers of the century, Voltaire, Buffon, and Diderot should not have known this feeling. For the God of Voltaire was not Providence, and His Creation was not made for man, who could feel only intellectual “adorations” for the master of the stars, those infinitely faraway stars that shone in the frozen sky of the province of Champagne.’ Buffon saw in nature only a domain * Le Spectateur francais was the title of a journal Marivaux edited for a number of years. — Tr. + Voltaire spent the years 1734-40, a particularly important period for his scientific and metaphysical formation, in Champagne. — Tr.

Epilogue 557 open for conquest by man. Just as it was “hideous” in the wilderness of the New World, so was it “beautiful” when “cultivated,” made salubrious, put in order, tamed by the hand of man. Diderot, finally, could not, and for good reason, seek God in the solitude of nature. Moreover, “it is only the wicked man who is alone,” who cannot live in the society of men.” Still, Diderot was not insensitive to the beauty of nature, and in certain letters to Sophie Volland, one feels a deep emotion pierce through, something akin to a primitive communion with the elements, with the October wind that moaned at the windows of d’Holbach’s chateau at Grandval, with the heavy, ploughed earth that stuck to the philosopher’s feet in his long walks with the baron, with everything that reduced man to his initial state of a figure immersed in living nature. This was really a vitalist temptation, to which Diderot did not give in intellectually, and to which, later on, the French romantic poets would be less sensitive than has been averred, they who considered nature less as a blind force than as the work of God. These few, briefly sketched comparisons simply prove what was already known: that humanity expresses itself similarly in everything it does. But they also show how the study of scientific problems should allow us to go beyond the realm of theory, discoveries, and knowledge and arrive at the underlying attitudes individuals and periods have adopted — often without knowing it— in the face of the fundamental problem of the human condition. Artists and philosophers may take the explanations of scientists to their contemporaries of what nature is as a point of departure for the construction of their universes. But the scientists themselves, immersed in the historical, social, and intellectual reality of their time, never succeed in creating an atemporal science. In their science, they depict themselves and their times. What they express in this way, through the problems they study, through the forms of knowledge they possess, which nourish and to some extent determine their reflections, is what one is obliged to call their “vision of the world,” for no term better expresses the immediate and intuitive content at the root of all human thought and even of the best-constructed systems. The elements of this “primary” intuition scarcely change, for they relate to the human condition. But their combinations vary infinitely, depending on temperaments, activities, social groups, and periods. The history of ideas and of sensibility should allow us to sort out this tangle somewhat, and by first bringing to light *The quotation is from Diderot’s play Le Fils naturel (The natural son; 1756). Rousseau took the observation as a personal insult. — Tr.

558 Epilogue the underlying tendencies of an age, enable us to distinguish the roles played by individuals, their professions, their classes, their nations, their times. My

goal has been to contribute materials for this analysis, not just because it should make possible a better understanding of the past, but because it should lead us to a better understanding of humanity.

Reference Matter

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NOTES ee

Preface to the 1993 Edition 1. See, e.g., Ernst Mayr, The Growth of Biological Thought: Diversity, Evolution and Inheritance (Cambridge, Mass.: Harvard University Press, Belknap Press, 1982), PP. 45-47. 2. See Paul Feyerabend, Against Method: Outline of an Anarchistic Theory of Knowledge (London: NLB; Atlantic Highlands, N.J.: Humanities Press, 1975), passim. 3. See Margaret C. Jacob, The Newtonians and the English Revolution, 1689-1720 (Ithaca, N.Y.: Cornell University Press, 1976). 4. Larry Laudan, Progress and Its Problems: Toward a Theory of Scientific Growth (Berkeley: University of California Press, 1977). 5. Mirko D. Grmek, Raisonnement expérimental et recherches toxicologiques chez Claude Bernard, Haute études médiévales et modernes, 18 (1971; Geneva: Droz, 1973). 6. Carlo Ginzburg, // formaggio e i vermi, translated as The Cheese and the Worms: The Cosmos of a Sixteenth-Century Miller (Baltimore: Johns Hopkins University Press, 1980).

7. Arthur Koestler, The Act of Creation (New York: Macmillan, 1964). 8. Jakob Burckhardt, Die Kultur der Renaissance in Italien (1860). 9. Unfortunately, even with the assistance of the AAAS and its archivist, no specific provenance could be discovered for the statement Roger quotes here. — Ed.

Chapter One 1. At the beginning of the seventeenth century, there were medical schools at Aix-en-Provence, Angers, Bordeaux, Bourges, Caen, Cahors, Grenoble, Montauban, Montpellier, Nantes, Orléans, Paris, Poitiers, Reims, Toulouse, Tours, and Valence. Some of the schools were moribund, such as Poitiers or Montauban, which closed in 1620. Others had only a nominal existence: Tours, for example, created by Henry IV, seems never to have opened. On the other hand, the process of territorial acquisition gave France the medical schools of Perpignan (1659), Orange (1673), and Dole (1678) —which was then transferred to Besancon—as well as the famous school of Douai (1714). Avignon, while not territorially French, was declared a French university by the edicts of July 1656 and April 1698.

562 Notes to Page 4 2. Jean Riolan ft/s, a physician-professor in Paris and son of the dean of the Paris medical faculty, specifically heaped scorn on the schools at Reims, Caen, Bourges, Valence, Angers, Cahors, Toulouse, Bordeaux, Aix, Avignon, Orange, and, generically, all those in Germany and Italy. See Riolan fis, #87, 20. The Parisians did not have much higher regard for Montpellier, as these amiable words of Guy Patin’s attest: “The rest of the writings by the Montpellier professors are a gibberish of pedantic readings... , a stinking swamp of ignorance and professional imposture” (#74, I: 210). A hundred years later, Jean Astruc, a doctor at Montpellier, proposed the disbanding of all the medical faculties except those of Paris, Montpellier, and Douai _ (see Astruc, #568, 97). The other faculties were “abandoned and inoperative” (ibid., 95). The two assertions are contradictory, and these less famous schools were in fact sought out by students, because the course of study at them—even for a teaching degree —was faster to complete. Thus we find Guy Patin, having been consulted on the choice of institution for a particular student, answering: “I would just as soon see him go elsewhere for his degree, where he would not take much time, such as at Reims, Caen, Angers, Valence, or Avignon” (quoted by Delaunay, #651, 38). These secondary faculties, it should be noted, kept abreast of scientific developments just as the great universities did. The theory of the circulation of the blood was defended at Reims in the same year as at Paris (see p. 30), and a thesis presented in Reims was not at all inferior to a Parisian one. In 1667, when Guy Patin was scornfully dismissing quinine as a matter for monastic simple-gatherers and “empiricals,” a professor at Reims, Pierre Oudinet, had the bachelier Jean Lhéritier defend the thesis “An febri quartanae cortex cynae cynae specificum?” [“Is cinchona bark a specific for quartan fever?” ], with an affirmative response; and this even before Louis XIV declared himself in favor of quinine (see Rousset, #832, 101). 3. The “silent” (muettes) faculties were so named because they awarded diplomas without providing instruction. For a time this was the case with Valence. See Rosenfield, #822, 3.

4. Certain universities, such as Bordeaux, Cahors, Angers, and Valence, “were publicly empowered to grant degrees without time spent in residence, and without insisting on the fulfillment of requirements” (ibid.). Others, such as Reims and Montpellier, maintained a rather strict posture with respect to candidates who wished to practice within the city itself, but were more indulgent towards those who intended to practice elsewhere. The doctors of Paris, who did not observe these distinctions, used them as a subject of vehement reproach vis-a-vis the professors of Montpellier. See Riolan ft/s, #87, and Patin, #74, 1: 129.

5. The students’ place of origin is found in the Registre d’inscriptions [enrollment registry] of the medical faculty at Montpellier, and for Paris in Baron, #574. On the other hand, a secondary faculty, such as Cahors, drew its students from within the province. See Bergougnioux, #581. Aside from the greater or lesser prestige of a particular university, one must take into consideration that diplomas obtained from a medical school gave the right to practice medicine only within the jurisdiction of that school. Only doctors licensed by Paris or Montpellier (later Avignon as well) had the right practice ubique terrarum. The latter arrangement did not go unchallenged:

Notes to Pages 4-7 563 the Parisians, for example, required in 1696 that their colleagues from Montpellier, of whatever age, enroll at the Paris Faculty of Medicine in order to retake all their examinations if they wished to practice in the capital. Among them were Daniel Tauvry and Joseph Pitton de Tournefort! 6. See Delaunay, #651, 69. This work has provided me with a great many facts, which I draw on here without specific reference.

7. See the historical account given by Jean Astruc, #568, 69. These two chairs were in fact created from nondoctoral teaching positions. 8. In Montpellier recruitment was theoretically carried out through competition. But the custom had been introduced among the professors to obtain “titles of succession” for their sons or sons-in-law from the king. Despite the complaints of the regional government of Languedoc, a decree of the Royal Council (Oct. 24, 1667), and the Solemn Edict of 1707 concerning the regulation of medical studies, this abuse still occurred in the mid eighteenth century. See Astruc, #568, 72. 9. For the procedures followed in these competitions, see Bergougnioux, #582,

and Dulieu, #673. 10. “Riolan spent his entire life seeking, unearthing, and discovering what the ancients had done, and rejecting the work of the moderns” (Pierre-Jean-Marie Flourens, Histotre de la découverte de la circulation du sang, quoted in Chauvois, #631, 214). The judgment is unfairly harsh, if one recalls that Riolan, who refused to admit the circulation of blood, did acknowledge the existence of the chyle vessels, discovered by Gasparo Aselli in 1622, to which Harvey himself never lent credence. Still, it must be admitted that Riolan was indeed attached to tradition. 11. The same method was used in England. Cf. the curriculum Harvey had to teach in London, starting in 1615, as “Lumleian lecturer” at the Royal College of Physicians (Chauvois, #631, 91 et seq.). 12. Thus Jean Fernel was the subject of two courses in Cahors, starting in 1623 (Bergougnioux, #581, 59). 13. Jean Riolan ft/s, who did not hesitate to descend from his rostrum to take up the scalpel, was an exception. He was a true anatomist, a rarity at the time. 14. See Hahn, #719. 15. For Paris, a complete list of subjects of theses defended between 1540 and 1762 is to be found in H.-Th. Baron’s valuable Quaestionum medicarum . . . series chronologica (#574). For the other faculties, we have far less complete information, to be found in works such as those of Bergougnioux, #581, Guelliot, #716, and Gidon, #699. 16. Paris doctors were strong partisans of bloodletting, but were careful not to overuse it. In 1625, Guillaume Dupre wondered in his thesis, “Vel medicorum parisiensium frequentes phlebotomiae jure vel injuria accusantur?” [Whether the frequent phlebotomies of the Paris doctors are used properly or harmfully?]. The medical community of Reims shared this sanguine tendency. See Guelliot #716, 36-37. 17. Denis Joncquet, “An aurora veneris amica?” (baccalaureate, Paris, 1637). 18. Etienne Bachot, “Est-ne medicus philosophus? Isotheos?” (baccalaureate, Paris, 1646).

564 Notes to Pages 7-8 19. Eusébe Renaudot, “An medico barba? Toga?” (Vesperies, Paris, January 9, 1648).

20. Etienne Le Gaigneur, “An daemonas in corpora sueuntes non-numquam internus calor imitetur?” (baccalaureate, Paris, 1638). Numerous allusions to the Loudun affair are found in Guy Patin’s letters [and see, too, on the subject, Aldous Huxley, The Devils of Loudun: Demonic Possession and Witchcraft in a Seventeenth-Century Convent (1952; New York: Harper Colophon, 1965).— Ed.]. We know moreover that

many doctors refused to accept the official thesis of demonic possession and said so loudly. See Pintard, #802, 1: 80. 21. The eighth chair at Montpellier, created in 1715, was earmarked for clinical teaching. See Delaunay, #651, 81.

22. In Paris, only the holders of the cence were supposed to participate in hospital examinations at the beginning of the century. Starting in 1644, on the example of Théophraste Renaudot, the faculty required bacheliers to participate in charitable consultations every Saturday. Ibid. 23. Patin, #74, 2: 152. Above and beyond the overly narrow conception of medicine, one already finds here a skepticism that would resurface in Fontenelle. See pp.

136-37. |

24. It is interesting to note the contents of doctors’ libraries in records of estate sales and seventeenth-century inventories kindly supplied to me by H.-J. Martin. Setting aside those of bibliophiles like Guy Patin, Jacques Montel, and the abbé Pierre Michon Bourdelot, one cannot but observe that these medical libraries were rather slim. Galen and Hippocrates were present, mainly in the form of digests and commenraries, with Aristotle far behind them. The moderns were still rarer, with the exception of André Dulaurens’s L’Anatomie. All of which demonstrates no particular desire on the part of the libraries’ owners to add to their learning. 25. War was waged, as well, against the druggists, who were so bold as to give advice to patients. They were attacked on their own ground, by teaching the public how to create remedies, syrups, teas, juleps, etc. This was the aim of Philbert Guybert's Le Médecin charitable (#46), in which the author lacks charity towards the druggists

but makes it clear that under no circumstances must the patient disregard the doctor’s advice.

26. Doctors were forbidden to consult with charlatans. In 1652, three Paris doctors, Bertin Dieuxivoye, Le Vignon, and Charles Le Breton, were suspended for a year for having consulted a certain Dr. Vallant from Reims, who was Anne of Austria's physician (Delaunay, #651, 302). It is hard to identify this Vallant with the doctor of the same name who was later to become the physician of Madeleine de Souvré, marquise de Sablé, and who was born in Lyon around 1631, practiced medicine in Montpellier, and arrived in Paris only in 1657 (Lévi-Valensi, #756, 519). Perhaps the the man in question was Antoine Vallot. 27. The quarrel between the faculties of medicine of Paris and Montpellier is one of the best-known episodes of French medical life in the seventeenth century. An account of it is found in Delaunay, #651, 304-9, and in Pauly, #798, 646-55.

Notes to Pages 9-11 565 28. See Patin, #74, 2: 539, and Delaunay, #651, 300, as well as the entire chapter on guild life. 29. With few exceptions, the seventeenth-century doctors were recruited from the bourgeoisie and lived as bourgeois. See Delaunay, #651, 14-17, 121-237. Without giving the word bourgeois too precise a meaning, they should particularly be distinguished from “intellectuals” and researchers. Riolan fils is said to have flown into a rage against Jean Pecquet, to the point of “criticizing the research that was being carried out on the human body, and saying that he was not a man to endure the lessening of his income in order to apply himself to new observations” (Bayle, #120, 42). Coming from Riolan, the words are odd and can only be interpreted as ironic. They are, however, indicative of a certain mentality at the time. 30. See the portrait of Guy Patin traced by René Pintard, #802, 1: 311-23. 31. See the titles of courses consulted: #72, #75, and #102. Another course, probably offered at Sedan, bore the title “Compendium .. . physiologiae” (#28), and in fact dealt with all of physics (the word still possessed its broad sense). 32. “Physica magistri Mercier,” #75, is interesting and curious in this respect. Nicolas Mercier vigorously rejected the “principles” of the moderns— Gassendi, Descartes, and the iatrochemists. But he accepted that the effects attributed to the abhorrence of a vacuum were due to the weight of the air. At the same time, he judged it “more probable” (244-45) that the heavenly bodies were moved by intelligences. Unfortunately, we do not know the precise date of this course, which seems to be from after 1650. 33. Mercier’s course, #75, is typical in this regard.

34. Apropos of the question: “Quot et quae sint principia” [“How many principles might there be, and what would they be?”], the “Compendium . . . physiologiae,” #28, cited fifteen philosophers in twenty lines, from the Pythagoreans to Epicurus. 35. The “Pars tertia philosophiae, physica” of 1630 (#72) is possibly even more Aristotelian than the “Compendium . . . physiologiae” of Sedan (#28), which must date from about 1615. 36. On the cost of medical studies, see Delaunay, #651, 37, 116. 37. On the rowdy distractions of the students in the sixteenth century, see ibid., 53-63. Nothing of the sort was encountered in the seventeenth century. 38. Ibid., 35.

39. Ibid., 291-94. |

40. On the forms of civic protection often afforded healers and doctors endowed with suspect diplomas and clever ways, see ibid., 311-18. 41. See, e.g., pp. 214~-15 on the attitude of Rouen College in the Houppeville affair. 42. Riolan fis, #87, 21. 43. On the abuses to which the college system could give rise, see Astruc #568, 95-96. 44. See Patin’s “Préceptes particuliers d’un médecin a son fils,” in Pintard, #803, 63.

566 Notes to Pages 11-14 45. These are the injunctions of the Pragmatics of Philip HI, quoted by Delaunay, #651, 340. This can no doubt be seen as a measure taken against the extension of Protestant-inspired chemical medicine. 46. Harvey, whose degree was from Padua, had to obtain a licence from Cambridge in order to be accepted into the Royal College of Physicians in London, which exercised rigorous surveillance over the practice of the profession, and teaching methods were the same as in France. See Chauvois, #631, 84, 88, and 91 et seq.; and on Harvey's medical life before the English Civil War in general, see 83-125. 47. The majority of the French students in Holland went there to study letters or law. The medical students became more numerous after 1620, as did the mathematicians around 1630. Most of the students were Protestant, and there were few Parisians. See Cohen, #632. Among the professors, few were important physicians and none were innovators. 48. The only great non-Italian European biologist of the period was Harvey, who had studied in Padua and was a disciple of Fabrizio d’Acquapendente'’s. 49. See Ménétrier, #774, 193, and Arnaldez and Massignon, #566, 444-45. 50. See Ménétrier, #774, 194-95, and Arnaldez and Massignon, #566, 439. 51. Accounts of Arab medicine are to be found in Castiglioni, #627, 236-56, and in Histoire générale des sciences, #727, 1: 430-71 (#566).

52. “What [the Arabs] knew about the organization and functioning of the human body came to them from the Greeks. For religious reasons, they did not practice dissection” (Arnaldez and Massignon, #566, 469). 53. See Ménétrier, #774, 119-200, and Beaujouan, #577, 530. 54. William of Saliceto’s Cyrurgia was published in five books in Verona in 1275. See Rivaud, #818, 2: 230. 55. Still, there had been a few direct transmissions. Thus, in the twelfth century, Burgundio Pisano translated some works by Hippocrates and Galen directly from Greek into Latin. See Beaujouan, #577, 527. 56. Callot, #615, emphasizes the revolt of the important minds against tradition and antiquity, citing Leonardo da Vinci, Peter Ramus, Paracelsus, Vesalius, Ambroise Paré, and Bernard Palissy. He is right where these important minds are concerned, but the rank and file did not follow in their wake. Callot himself has to acknowledge that “authority, learning, and dialectic constituted the basic mentality of the Renaissance naturalists” (17). This is precisely how I see it. 57. See Delaunay, #651, 490, and Guardia, #715, 51. Castiglioni does not, however, mention this auto-da-fé in his Storia della medicina, #627, 1: 389-94, and Pagel believes that Avicenna’s Canon was the object of the ceremony (#796, 20-21). Finally, Koyré notes that “in the thirteen volumes published by K. Sudhof, the course given in Basel in 1527 is the only one in Latin” (#737, 48 n. 3). Whatever the merits of the anecdote, it is certain that Paracelsus scarcely wrote except in German. 58. According to Mazahri, #772, Paracelsus owed all of his chemical science and the prescriptions in his pharmacopoeia to Chinese medicine, which he supposedly

discovered in Istanbul. He was, in Mazahri’s opinion, not an experimenter, but a scholar who did not always understand what he read.

Notes to Pages 14-18 567 59. On the thought of Paracelsus, see Koyré, #737, and Pagel, #796. 60. “Gargantua (this is Vallot’s name at court since he killed Gargant, the minister of finance, with his antimony),” writes Guy Patin (#74, 3: 77), but Patin says elsewhere (#74, 2: 287), that Gargant died of “grief, at having lost a million, and having taken three doses of emetic wine at the hands of Guénault and Raissant.” Vallot, a great patron of the Montpellierians in Paris, was one of Guy Patin’s bétes noires. But Francois Guénault, a fashionable physician and a chemist as well, was not in greater favor with him. In any case, once the poison has been identified, what difference does

it make whose hand poured it? , 61. See Guelliot #716, 88. 62. Renaudot, #81, 4: 235. Lecture of Aug. 29, 1639. The prescription is found in Paracelsus’s Archidoxe magique, #69, 29-30. It had been taken up again and defended at length by Helmont in his De magnetica vulnerum curatione..., #48, published in Paris in 1621.

63. For example, the young Gabriel Naudé, then a medical student in Paris, “expressed the conviction that where philosophy and medicine are concerned, tradition and reason are not mutually exclusive. ... The cult of circumspection and good sense went hand in hand in him with gratitude, inspiring a rigorous censure of the iatrochemists, Paracelsists, and hermeticists, — along with praise for the old disciplines” (Pintard, #802, 1: 159). One finds the same attitude in Antoine Menjot, a defender of dogmatic medicine against the “alkalists” (see Menjot, #64, 149-51). This attitude seems to have been shared by the Gassendists in general, and Fontenelle, who thought Paracelsus merely a visionary (see Fontenelle, Dialogues des morts, 2d ser., “Morts modernes,” 2d dialogue), had obviously inherited it. 64. See, e.g., the bedazzlement of Nicholas Fabri de Peiresc in 1622 after his first microscopic “observation” (Hubert, #730). 65. No better example can be given than the discovery of spermatozoa. See pp.

236-47.

66. Pierre de Beauvais, “An aquae minerales mulieres foecundent” [“Do mineral waters possibly render women fertile?”] (baccalaureate, Paris, 1616). 67. Charles du Pré, “An cerevisia nutricibus?” [“Should beer be prescribed for nursing women?’ ] (baccalaureate, Paris, 1629). 68. Charles du Pré, “An dentium dolor, manuum frigiditas amoris signum?” (Vespéries, Paris, Nov. 12, 1631). 69. Pierre Yon, “An intermissa diu Venus suavior? Foecundior?” (Acte pastillaire, Paris, Nov. 28, 1672). Similar topics are to be found in Delaunay, #651, 103-4. H.-Th. Baron put together three volumes of Theses erotico-medicae!

70. See p. 17. 71. Nicolas Régnier, “An a praematura venere sterilitas? Aff.” [“Does sterility come from premature sexual activity? Affrmative”] (baccalaureate, Paris, 1619). 72. Michel Toutain, “An venus virginibus Hystericis? Pallidis?” [“Does sexual activity make unmarried women neurotic? Does it make them pale?”] (Acte pastillaire, Paris, Feb. 27, 1601).

73. See Guy Patin on “suffocations of the womb,” #73, 109.

568 Notes to Pages 18-19 74. A very large number of theses were devoted to the problem of fertility in marriage, and most of the works dealing with reproduction broach this clearly very important question. 75. Charles Le Breton, “Est-ne geminorum primogenitus, qui prior in lucem editur? Aff.” [“Is the older twin not the one who first sees the light of day? Afhrmative”’]

(baccalaureate, Paris, 1638). , 76. “Which is the elder of two twins?” Lecture of July 18, 1639, in Renaudot, #81, 4: 177 et seq. 77. “Comment s’engendrent les masles et les femelles?” in Renaudot, #81, 3: 897 et seq. 78. Quillet, #78 and #79. The latter edition has been consulted here.

79. Venette, #403. The Catalogue des imprimés of the Bibliothéque nationale gives the principal editions of this work. 80. This habit was not peculiar to France. “Natura voluit mares foeminis incumbere in coitu, foeminas vero adhinnere quidem, non autem insilire aut inequitare maritis, infesto et infausto foeminini dominii omine,” Francesco Plazzoni wrote, in a passage I beg leave not to translate (#77, 80). 81. “Esson de pollo édetai € guni tou andros en té mixei pleiona de khronon é o anér,” Hippocrates had written (Peri gonés, in #14, 7: 476). In his edition of 1529, Cornarius adopted this reading (#10, p. 141, col. 2), which he translates as: “Caeterum multo minus delectatur foemina quam vir, longiore tamen quam vir tempore” [Moreover, the woman has far less enjoyment than the man, but it lasts for a longer time than with the man] (ibid., col. 1). But in his edition of 1545, Gorraeus — alias, Jean de Gorris, a Paris physician—presents and translates a text from which the é has disappeared before 0 anér, and that thus attributes to the man not only the greater intensity, but also the longer duration of sexual pleasure (#11, 5-6). In 1549, a Paris edition of Cornarius’s version (#12), adopted Gorraeus’s reading and modified the translation accordingly. It is this corrected translation that one finds, in French, in Guillaume Chrestian’s version (#13, 83), and that would subsequently be found among almost all the physicians of the seventeenth century who quote this text. In the same spirit, Johann Sperlingen thought that the act of nursing a child was “unworthy of men, born for higher tasks,” which was why men had no milk (#97, 15). 82. “To which is one more obligated, father or mother?” Lecture of May 3, 1639, in Renaudot, #81, 4: 89. “Which does a child more resemble, father or mother?” Lecture of Mar. 18, 1641, in ibid., 849. 83. Ibid., 850.

84. Ibid., 851. It is understandable that a writer of love literature such as SaintGabriel would wish to demonstrate the importance of the woman's role in reproduc-

tion (see, e.g., #89, 203-17). } | 85. Gautier-Dagoty, #456, 18.

86. For example, Jean-Francois Callard de la Ducquerie’s baccalaureate thesis, presented in Caen, May 5, 1694, answered the question “An humani partus tempora ad decimum quartum mensem prorogari possunt?” [“Can the time of human parturition be extended to the fourteenth month?”] in the affirmative, citing several ladies

Notes to Pages 19-22 569 in the environs of Caen and of Vire whose children had been declared legitimate even though born between thirteen and eighteen months after the deaths of their putative

fathers (see Gidon, #699, 36, 42). The questions of the duration of pregnancy and of late births were dealt with in almost all writings concerned with procreation, the delays granted nature often being very generous. The social importance of the question is evident. 87. Costeo, #29, I. 88. Renaudot, #81, 4: 853. 89. Thus Janus Orchamus (alias Johann Vorst) showed that the Hippocratic conception of the male seed was implied in the biblical formula egressi e lumbis Abraham [having come from the loins of Abraham] and similar expressions. The existence of a female seed was supported in the same fashion. See Vorst, #409, 22-28. The Aristotelians were generally exempt from these concerns, for, at least as of the sixteenth century, the authority of Aristotle often outweighed that of the Bible considered as a scientific work.

90. Dugardin, #35, 66-67. 91. Sinibaldi, #94, cols. 93-102. Gregory of Nyssa did not hold this opinion, but Molina leaned towards the affirmative, and Sinibaldi agrees with him. He even adds that for Adam and Eve, there existed a “coitus voluptas, regulata quidem, sed longe perfectior et intensior” [sexual intercourse that was a pleasure, controlled certainly, but by far more perfect and more intense] than that of fallen man. Still, Adam and Eve, once created, began by adoring the Creator, whereas the animals immediately coupled, which was possible, for their vasa spermatica were already filled with the necessary seed. One can only admire these clarifications! The question of Adam and Eve’s lovemaking is raised quite often, no matter the scope of the work. 92. Ibid., cols. 56-61. Sinibaldi, whose work dates from 1642 and was republished in 1669, was far from being a fool or a run-of-the-mill intellect. Neither a chemist nor a mystic, he made fun of Paracelsus and his homunculus and was able to adopt a critical stance with respect to the ancients, making him an all the more significant example. Similarly, undertaking in his Quaestiones in Genesim to calculate the tonnage of Noah’s Ark, Father Marin Mersenne omitted “the animals that are born from putrefaction, such as mice, lice, flies, etc.” (quoted, in the original Latin, in Lenoble, #749, 234).

93. Mundinius, #67, fol. 106. 94. Liceti, #58, 243.

95. Feyens, #39, 1-2. 96. Ibid., 128. 97. Ibid., 130. 98. Renaudot, #81, 1: 170-80.

99. Ibid., 172. 100. Ibid., 176.

1o1. Sinibaldi, #94, col. 604. 102. Graindorge, #45, 2. 103. Fernel, #38, 2: 393.

104. Giovanni Costeo saw all these difficulties very clearly when he wrote concerning the development of the embryo: “We can know nothing about it, except through observation of aborted embryos. Now, it is not likely that it would befall someone to see so great a number of embryos, from 6, 9, 15, 27, 30, 35, or 40 days, of I, 2, 3, 4, 5, 6, 7 weeks, and of each month until the ninth. And if someone has been

570 Notes to Pages 22-28 able to see them, it is not easy to draw solid conclusions from them, for the date of conception is rarely known, and hardly by the most attentive women endowed with the most precise sense of things. And even if one knew it, the strength of the formative faculty and of the heat is not the same among all women. And what has been established once cannot be proclaimed a perpetual rule for man” (Costeo, #29, 7-8). 105. See “Historia foetus mussipontani ... ,” #53. The event occurred in 1659. 106. Liceti, #58, 274. 107. The psychological mechanism at work is very simple: the accumulation of circumstantial details is charged with making the account more plausible.

108. Liceti, #58, 273. 109. The story of the Autun egg. 110. Schenck, #91, 134. iI. Liceti, #58, 273. 112. Some of these facts are plausible in the eyes of modern biology, and others are pure fantasy. But in the seventeenth century, the distinction was not always apparent.

113. Weinrich, #103, fol. 7. !

114. Plazzoni, #77, 150. 115. Aldrovandi, #18, 355. 116. “More than from naiveté, he suffers from the intellectual incontinence of the

men of the Renaissance; he is incapable of setting a question aside. He knows and states that certain stories he reports are fables, but he cannot help it, he has got to talk about them!” Robert Lenoble writes of Mersenne (#749, 70). The whole page is worth reading, incidentally, on the difficulty then in “orienting oneself amid the gossip.” As regards the scholarly activity of the period, see, too, Pintard, #802, 1: 89, on the subject of Burgundian magistrates. 117. Riolan pére, #84, fol. 19. 118. Mundinius, #68, 308. 119. Liceti, #58, 234. 120. See Aristotle, Historia animalium 8.28.8, in #1, 1: 525; id., De generatione ant-

I: 216-17. ,

malium [hereafter cited as Gen. an.] 4.3.769b, in #2, 418-19, and 2.4.738b, in ibid., 185; Lucretius, De natura rerum, #15, 5.878 et seq.; Galen, De usu partium 3.1, in #9,

121. Riolan pére, #84, fol. 19. 122. Liceti, #58, 168. 123. This immense subject cannot adequately be dealt with here; but see Lenoble, #751; id., #749, ch. 3.

124. Renaudot, #81, 2: 291. It is interesting to note that the cure for a wound through the weapon remedy was accompanied by the following attentions: “Every morning, the invalid must wash his wound with his urine, or with warm water, while wiping off the pus that would impede closing” (ibid., 290). The use of urine was traditional, and its antiseptic action has been documented by modern medicine. It is a good example of the mixture of the mystical and the empirical that characterized chemical medicine. 125. On all of these points, see Pagel, #796, 56-65. 126. Renaudot, #81, 2: 296. 127. Aristotle, Gen. an. 2.3.769b, in #2, 170-71; #3, 2: 40-41.

Notes to Pages 28-30 571 128. Riolan pére, #84, fol. 7. 129. This list comes from Feyens, #40, 2, who opted for the spiritual soul. 130. Galen, Peri phusikén dunameon (On Natural Faculties), in #9, 2: 219. 131. A “natural” explanation of the existence of “two monstrous brothers living in the same body” (Renaudot, #81, I: 177). 132. On mules, see ibid., 4: 230. 133. Ibid., 235.

134. Demons often made their appearance among the medical concerns of the seventeenth century. It was heatedly debated whether or not they could beget offspring. The question was still being raised, and was resolved in the negative, in 1675 in Rheims, by the bachelier J.-P. de Lespierre. But already in 1637, the doctors of Renaudot’s discussion group were very reticent. Of four speakers, one alone believed that demons could produce offspring. For another, they intruded into dreams, but they could not beget. The last two were radically incredulous, and the fourth specified that supposed interventions by incubi or succubi were merely “a symptom of the animal faculty, accompanied by three circumstances: namely, impeded breathing, hampered movement, and a voluptuous imagination” (ibid., 3: 376-77, discussion of Feb. 9, 1637). In these questions, as in all matters concerning witchcraft, the physicians generally leaned towards natural interpretations. In general, one may say that science was very secularized in the early seventeenth century. It was known that science should be concerned with “secondary causes” and not bother itself with the “Primary Cause.” At Renaudot’s meetings, indeed, the proclamation was made that “it is borrowing from superstition to wish to attribute natural things to their Author, without at all investigating the means through which He produces them.” And even extraordinary facts “have nonetheless their true causes, just like all the rest that occur ordinarily” (ibid., 1: 171). The good sense of the physicians from the schools, their attachment to an ancient tradition free of religious concerns, their prudence, and their lack of interest in the supernatural, all these qualities, which may have derived both from the bourgeois character and from a certain skepticism passed down from the sixteenth century, explain this secularization of science, which led them to set aside the intervention of the supernatural—but not necessarily to foreswear recourse to sacred texts, which was a different matter. What was at issue here, in any case, was the very notion of a “natural” fact. 135. We should recall, in any case, that in the eyes of the Cartesians, Newtonian attraction passed for an “occult quality.” See Fontenelle, “Eloge de Newton,” in #211. 136. “Hardly can one point in nature to a fact certain and constant enough so that it cannot be refuted by some contrary example” (Riolan pére, #84, fol. 17). 137. On spontaneous generation, see Renaudot, #81, 3: 700. 138. Capillaries were to be discovered by Malpighi in 1661. See Guyénot, #718, 172.

139. Thus Parisanus in 1633. Ibid., 173. 140. Chauvois, #631, 209 et seq. 141. Fagon: “An sanguine impulsum cor salit? Aff.” [“Does the heart beat from a pulsation of the blood? Affirmative”]; Lallemand: “An sanguis per universum corpus

572 Notes to Pages 31-36 circulariter moveatur? Aff.” [“Does the blood circulate through the whole body? Affirmative’ ]. 142. Fontenelle, “Eloge de Fagon,” in #211, 1: 36.

143. Mattot, “An motus cordis a fermentatione? Neg.” [“Does the heartbeat come from fermentation? Negative’ ]. 144. Cordelle, “An sanguis per omnes corporis venas et arterias jugiter circumferatur? Neg.” [“Is the blood conveyed continuously through all of the body’s veins and arteries? Negative]. 145. Bazin, “Est-ne sanguinis motus circularis impossibilis? Aff.” [“Is not the circular motion of the blood impossible? Affirmative’ ]. 146. Malebranche, De la recherche de la vérité, #314, 2.2.2. 147. Guyénot, #718, 134. 148. Mersenne, La Vérité des sciences, quoted in Lenoble, #749, 69. 149. Renaudot, #81, 1: 171-76. 150. Quillet, #79, 77 et seq. 151. Fabrizio d’Acquapendente’s 1625 Opera physica was a contrived miscellany of various little works, some of them published during the author’s lifetime, others only after his death. Fabrizio’s ideas on generation are set forth in the treatise De formation ovi et pulli (#37), published in 1621 and reprinted in the 1625 collection. 152. Guy Patin refused, for example, to see a wondrous phenomenon in the Ponta-Mousson fetus (Historia foetus mussipontani, #53, 3) and rejected occult qualities (letter to Belin, Oct. 28, 1631, in #74, I: 9), albeit mostly because he was able to cite against them “more than fifty specific passages from Hippocrates and from Galen.” The bachelier Jacques Mantel also rejected occult qualities in his thesis in 1630.

153. See inter alia the writings of Gaston Bachelard (#570), Léon Brunschvicg (##607-8), Robert Lenoble (#749), and Alexandre Koyré (##736-39). 154. See Pintard, #802, 1: 96. 155. See Brown, #597, 69. 156. Ibid., 136. 157. Le Gallois, Conversations de l’'Académie de M. labbé Bourdelot, #284, 59. Le Gallois’s preface names, among many others, Dodart, Denis, Pecquet, Borelli, Steno, and Régnier de Graaf. 158. Ibid., 62. 159. Le Gallois, #285, 1: 148. 160. Guy Patin, letter to Charles Spon, Sept. 24, 1658, in #74, 2: 436. 161. Renaudot, #81, “Avis au lecteur.” 162. Ibid., 2: 292. 163. Ibid., 3: 370. 164. Le Gallois, #284, 93-94. These conversations are unfortunately not dated. 165. Guy Patin, letter to André Falconet, Jan. 22, 1672, in #74, 3: 795.

Notes to Pages 37-42 §73 Chapter Two 1. Cardelini, #26, 5. 2. “There is nothing in anatomy that has so tortured and exercised the minds of doctors as the formation of our body, a formation that it is far easier to explain by words than to construct in fact” (Riolan ft, #85, 334). 3. Sinibaldi, #94, col. 604. Like Sinibaldi and most of his contemporaries, I am classifying the authors here according to their opinion on the female seed. The Aristotelians did not admit its existence, others admitted it, and it was the central point of the debate. 4. Caspar Hofmann calls Fabrizio a demigod (semi-deus) in #54, preface. 5s. Ibid., 1.

6. See two excellent books, Riolan fis, #85, and Bartholin, #23. 7. Sisinius seems to have confused the two concepts under the same word. Mundinius gave the titles De semine and De genitura to two editions of the same work. When the distinction was made, it was specific to the author. Vittore Cardelini calls the sperm genitura, and the mixture of the seeds, semen, which Giovanni Costeo, on the contrary, calls genitura. For Anton Deusing, genitura signified the materia semtnis ante coitum. For Sinibaldi and Cremonini, genitura was the substance of the seed [male or female], the basis of its activity, and semen designated the male seed as material and active principle. This uncertain terminology was at times a problem. 8. Guyénot, #718, 313 et seq. 9. Aristotle, De generatione animalium (hereafter cited as Gen. an.] 2.2.735a-739a; in #2, 156-65. 10. Galen, “De semine,” #6. 11. These considerations are found among all the authors. The allusion to Aphrodite, which dated back at least to Galen, is still found at the end of the seventeenth century. 12. Leaving aside; for the present, the question of hybrids and teratisms. 13. For simplicity’s sake, I use this single name to designate the diverse authors of the Hippocratic corpus. In any case, the works that interest us here—the De genitura and the De natura pueri—both in fact belong to the School of Knidos (see Rey, #816, 429; Bourgey, #596, 289). Littré considered them the work of the same author, and they do in fact display great unity of thought. The sixteenth-century scholars were not unaware of these difficulties in attribution, which had already existed in Galen’s time. Thus, contrary to Galen, who had attributed the second to Hippocrates himself, Cornarius attributed both treatises to Polybius (see Hippocrates, #10, 144). But the physicians were not much concerned with these questions, and they mostly refer simply to Hippocrates. 14. Rostand, #823, 12-16. 15. Hippocrates, Peri gonés, in #14, 7: 475. 16. [bid., 471. 17. Ibid., 473. 18. Riolan péve, #84, fol. 8.

574 Notes to Pages 42-45 19. Aristotle, Gen. an. 1.18.724a-726a, in #2, 70-89. Aristotle refutes the theory deriving the semen from all parts of the body at length (ibid., 1.17~-18.721b—724