Thomas Aquinas - God and Explanations 0748609016, 9780748609017

Table of contents :
Introductory Preface
Acknowledgments
Copyright Permissions
The "summa theologiae" as a summary of a divine science;
The nature of science in medieval thought;
The role of questions in the articulation of science;
The signification of a name;
The notion of existence used in answering "an est?";
Demonstrating the existence of a cause from its effect;
The existence of God as a scientific question;
"Does God exist? Apparently not";
The First Way;
The Second Way;
The Third Way;
The Fourth Way;
The Fifth Way.
Select Bibliography
Index

Citation preview

THOMAS AQUINAS God and Explanations

C. F. J. Martin

Edinburgh University Press

© C. F. ]. Martin, 1997 Edinburgh University Press 22 George Square, Edinburgh Typeset in Monotype Ehrhardt by Westkey Ltd, Falmouth, and printed and bound in Great Britain by CPI Antony Rowe, Eastbourne A CIP record for this book is available from the British Library

ISBN 10 0 7486 0901 6 ISBN 13 978 0 7486 0901 7

The right of C. F. J. Martin to be identified as author of this work has been asserted in accordance with the Copyright, Designs and Patent Act (1988).

CONTENTS

Introductory Preface Acknowledgements Copyright Permissions

1. The Summa Theologiae as a Summary of a Divine Science

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1

2. The Nature of Science in Medieval Thought

15

3. The Role of Questions in the Articulation of Science

32

4. The Signification of a Name

37

5. The Notion of Existence Used in Answering an est?

50

6. Demonstrating the Existence of a Cause from its Effect

80

7. The Existence of God as a Scientific Question

97

8. 'Does God Exist? Apparently Not'

110

9. The First Way

132

10. The Second Way

146

11. The Third Way

155

12. The Fourth Way

171

13. The Fifth Way

179

Select Bibliography

207

Index

209

INTRODUCTORY PREFACE 1

Like many other people, I have tended in the past to skip prefaces and introductions. I have always felt that if an author puts something he wishes to say to me outside the body of his book, then I am under no obligation to read it. This is ridiculous, of course, since I am under no obligation to read any of the book at all. But my experience suggests that this ridiculous attitude of mine is fairly common. Let me make a plea: do not skip this preface unless you are sure you want to. What I have to say now cannot properly form a part of what I have to say in the book, but I am sure that it needs saying. I only hope my readers will be sufficiently warned by this first paragraph that if they do skip the reading of it they may fail to understand the book. Worse, if they skip the preface they may find themselves reading something they do not like, or leaving aside something they would like. Since the days in which I was an undergraduate a change of nomencla­ ture has been spreading over the teaching and the writing of philosophy in Britain. When I was young, all those who taught or learnt in philosophy departments were considered to be philosophers, in some sense, and to be doing philosophy. It was out of fashion at the time to try to do philosophy entirely out of one's own head, and I approved and approve of this modest fashion. Since not everyone can manage to do everything, and since tastes differ, what philosophers principally read to support the efforts of their own minds varied. Some read principally Kant; others, principally the empiricists. Some, the kind I liked best, read principally the ancients, and a very few read the medievals, as I have done since those early days in philosophy. Others, meanwhile, were working in more restricted but more rapidly moving fields, and read principally their contemporaries. Each choice was respected by the others, at least to the extent that those who chose to do their philosophy one way recognised the right of others to choose to do philosophy another way. All were willing to concede to the others the right to claim that they were trying to do philosophy, even though they may have thought that those others were not going the best

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way about it. All were more or less aware of the restrictions and advantages of their own choice, and of those of others. (Usually, of course, they were more aware of the advantages of their own choice, and of the disadvantages of the choices of the others, but that is natural.) It was a fairly free and relaxed world, in my recollection of it, and no-one would refuse to cite a contemporary author in support of his or her view of an ancient text, or refuse to cite an ancient author in support of a step in a contemporary debate. We were all philosophers. But between ten and fifteen years ago I began to find that a new name was being given to the kind of studies I was interested in: searching for the wisdom with which to answer problems people have had all through the ages, problems apparently inseparable from the great problem of being a human being, in the writings of those who had been dead for more than seven hundred years. My interests were now being called 'the history of philosophy'. I felt at the time that the name was inappropriate. It is a matter of fact that in almost any schedule of examinations for undergradu­ ates there will be some papers which are to be answered principally by reading material written by people still alive or not long dead, and some papers which are to be answered principally by reading material written by those long dead. It seems to me natural that the latter should be called 'historical' papers, though there might be another half-dozen labels at least as natural. But to call them studies in the 'history of philosophy' seemed, and seems, misleading to me. There is a discipline, or set of disciplines, called 'science'; and there is a separate discipline called the 'history of science'. There is 'art', and there is the 'history of art', quite separate; and there is 'music', and there is the 'history of music', also quite separate. While it is hard for people who know no music to study the history of music, it does not seem to me impossible. But I would claim that it is impossible for those who know no 'philosophy' to study the 'history of philosophy'. (I would also be inclined to make the stronger claim that those who study 'philosophy' and care little for the 'history of philosophy' will remain with a severely limited understanding of 'philosophy', but I do not intend to press this claim at once.) The label, which implies that 'history of philosophy' is not philosophy, seems to be at best misleading. Perhaps I should have said 'I would have made one or other of these claims' for as I found my own studies labelled the 'history of philoso­ phy', inaccurately enough, I began to notice the growth of a subject which could also be called the 'history of philosophy' with a good deal more accuracy, a subject of considerably less interest to me. I found myself increasingly subjected, at conferences and in reading journals, to productions which seemed to me to be lacking in any philosophical

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interest, except incidentally. These productions showed a breadth and a depth of erudition that I could not aspire to: I do not have the necessary patience or eye for detail. But these admirable qualities seemed to be directed indiscriminately to any object, provided that it was within the scope of what people would now or would once have called 'philosophy'. A case in point was the loving care directed to the reading, recovery and elucidation of hitherto wholly neglected medieval texts which dealt with the medieval logic exercise of oppositiones. Listening to or reading these papers I noticed that either the medieval authors or their contemporary commentators were incapable of distinguishing between suggestions for winning strategies and proposals to improve the rules of the game. It seemed clear to me that no logical insight was to be derived from the studies of these texts, and so I neglected them. I was allowed to: I was lucky. A colleague of mine wrote a introductory book on medieval logic, in which he confined himself to those authors and texts which, in his (generous) view could afford valuable logical insights. A distinguished historian of logic said in print that this book should be consigned to the flames. This, besides being a highly offensive thing to say to a Jew, as my colleague is, implies to anyone familiar with the writings of Hume that the book contains nothing but 'deceit and sophistry'. Strong attitudes indeed. I, and those who thought like me, found ourselves in danger of falling between two stools, the only two stools currently permitted. On the one hand was the stool of 'philosophy' which means developing some currently fashionable topic, in however detailed or trivial a way, basing oneself solely on material published within the last few years- or, since the advent of e-mail and the Internet, to be published within the next year or so. On the other hand was the 'history of philoso­ phy', whose exponents seemed to be pure scholars, caring little or nothing for philosophical importance, or even logical importance, but only for the erudition of digging up the past- not, I fear, to learn from it anything that might be of value to anyone today who is exercised by that wonder which is traditionally said to be the origin of philosophy. The case of the history of logic is particularly interesting. It may be objected, perhaps fairly, that I seem to want to go back to a dilettante age, now fortunately superseded, of elegant gentlemen reading the classics for their own improvement. I have no objection to elegance, though I am not elegant, and no objection, other than political and economic, to gentlemen, though I am not a gentleman, and I certainly have no objection to people, of any class or level of elegance, reading anything with the desire, however far-fetched, of 'self-improvement', of making themselves better people. I certainly wish to improve myself, in many senses of the word, and I think

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that reading classic authors, in a broad acceptance of that word, may come to be a way of self-improvement. This criticism passes me by. If the alternatives suggested to me seemed of more value to myself, my friends or to society, then I might consider them. If another Ruskin came to ask me to help build a road to Hinksey village, I might join in. But I cannot see any reason to suppose that to devote myself to what is now called 'philosophy' or what is now called the 'history of philosophy' would contribute in any way to the improvement of myself, to the improvement of anyone else, to the well-being of Hinksey villagers, or even to the innocent gaiety of nations. A more serious criticism would be the following: these gentlemen you seem to admire lacked sufficient grasp of historical perspective. The problems dealt with in, say, the Middle Ages, were not the problems we face today, and the concepts they employed in their answers were not our concepts. We cannot learn from them, because we do not live in their world. One cannot learn to live well from Aristotle's theory of excellence, say, because that theory was developed in a wholly different social and political context from our own; and the same objections apply to Aristotle's medieval heirs. Their world is not our world, our faith is not theirs, and they are in any case as likely to have misunderstood Aristotle as much as your beloved elegant gentlemen did, or as the dons of the early twentieth century did when they insisted on translating Plato's polis as 'state'. Any differences between what Plato said of the polis and what they would be inclined to say about the state could be attributed to a mistake on Plato's part. Collingwood famously pointed out that this was about as sensible as translating Plato's word trieres, a trireme, as 'steamer', and then drawing attention to the odd ideas the Greeks had about steamers. I do not think this criticism is valid. First, I do at least claim to share, for example, a great deal of the faith of Aquinas, and thus I am convinced that it is not impossible for me to share a great many of his concepts, his problems and his answers to these problems. Moreover, I neverthe­ less live among my contemporaries, and though I strongly differ from them in all kinds of mental and moral attitudes, I have little difficulty in understanding them, and little more difficulty in making myself (at last) understood. This last claim, of an asymmetry between my under­ standing of my contemporaries and their understanding of me, is not, I think, arrogance: it is merely recognising my position as a member of a religious or conceptual minority. The average intelligent Jew or Muslim in Britain understands far more about Christianity than the average intelligent Christian understands about Judaism or Islam, and all three

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understand more about secular practical atheism that the average intel­ ligent person in this country understands about monotheistic revealed religion. So in a case where the facts are little in dispute I think I can make good my claim that understanding of an alien way of thought, and learning from it, is not impossible. The case of the history oflogic comes in pat, strongly on the same side. There is no more possibility of denying that logic has made great strides over the last 120 years than there is of denying the similar progress made by aeronautical theory and engineering. (The remembrance of Wittgenstein leads me to put these two examples to­ gether.) No logician in the English-speaking world would deny it, and very few would even refuse to use the very expressions I have used. There does exist a set of undeniable logical principles and propositions, which are better known and better understood than they were in Kant's time, for example. No-one with sufficient knowledge would deny that this set was better known and better understood in, say, Aquinas's or Mair's day than they were in Descartes' day. Thus some writings of medieval phi­ losophers and logicians do have a pure abstract logical interest (while other medieval writings, such as those on oppositiones, just like the logical writings of the period between Descartes and Boole, say, do not), and it would be sensible for a logician of the present day, were he or she skilled enough, to consult them. This is, I think, undeniable. And what is true of logic, is true of other branches of philosophy, though the investigations in these other branches must be carried out with more caution. There really is a set of unchangeably true propositions about, for instance, the relationship between our language and our world. Any human performance of which these propositions did not hold we would not be able to recognise as a language at all. In the same way, there are propositions about our world and about ourselves whose truth we cannot deny, while continuing to live in the same linguistic world as our fellows. That we all must die, that we need to eat, be covered, enjoy ourselves, that we need company and some kind of friendship, that we are animals and have some compulsion to reproduce, none of these can be denied. That we are compelled to look for explana­ tions, and go beyond the intellectual skills which suffice to adapt us to our environment, are also true. That we are puzzled by change and time, by the structure of our world, and that many people have an urge to look for an explanation, not of this or that phenomenon but of the world as a whole, all these are true. They were true in distant ages as well, and though it may seem possible to deny that the thoughts of people of distant ages may

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be of value to us, this denial is no more respectable than is the idea that foreigners are intrinsically funny. I am not arguing for the existence of 'perennial problems' in the sense that our perhaps trivial and transient concerns and methods of investi­ gation can be projected back on to the writers of the past. I have recently published a book in which I argue that such a performance is a mistake. But it is a mistake because it limits our chances of learning from those who have gone before us. If we make this mistake, like the dons satirised by Collingwood, we will look only for the answers to our current problems and have our eyes closed to the perhaps greater problems the ancients or the medievals might have shown us. We may even have our eyes closed to all but the sort of answer we might have been inclined to look for in the first place. At the very lowest level, to go to older writers to look for answers to current problems only will close our eyes to the fact that these writers had their silly and trivial current problems as well, and we will not be able to make the comparison and see many of our own problems as silly and trivial. To read former writers in such a spirit is not what I recommend. But I do protest against the abandonment of any attempt to go back to former writers to learn from them, an abandonment which is implied in the current opposition between 'philosophy' and 'the history of philoso­ phy'. I know I am not alone in this protest and that many better writers have said what I am trying to say. Among the most popular are Martha Nussbaum and Alasdair Macintyre; I think it is not a coincidence that their works are read by people who would not dream of reading anything written in what is now called 'philosophy' or 'the history of philosophy'. But, apart from my lack of talent compared with these two authors, and with many others, I face further difficulties. I am writing on medieval philosophy, which was not accepted as serious or real philosophy when I was an undergraduate, as ancient philosophy was. If I were writing on Aristotle I should face a less difficult task: the task of bringing back something that existed and flourished in the English-speaking world as recently as twenty years ago and which is still practised by some. I have a far harder task. It is noticeable that the vogue for Macintyre has fallen off considerably since he started talking more about the Middle Ages than about the ancients or about the Enlightenment, and still worse, started talking about God. The task I am attempting in this work is that of 'analytical Thomism'. The recently published Oxford Companion to Philosophy tells us that this is a broad philosophical approach that brings into mutual relationship the styles and preoccupations of recent English-speaking philosophy

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and the concepts and concerns shared by Aquinas and his followers. This approach bears some relation to that of those post-war Oxford philosophers, e.g. Austin and Ryle, who sought to reintroduce certain concepts into the analysis of thought and action, such as those of capacities and dispositions, which are prominent within Aristo­ telian philosophy. In the case of analytical Thomists the primary areas of interest have been intentionality, action, virtue theory, philosophical anthropology, causation, and essentialism. The ex­ pression 'analytical Thomism' is rarely employed but it usefully identifies aspects of the writings of philosophers such as Anscombe, Donagan, Geach, Grisez, Kenny and Macintyre. There is pretty clearly no room for analytical Thomism either within 'philosophy' or 'history of philosophy'. It is noticeable that most of the writers mentioned above are of an older generation and achieved a position before this division became accepted or, in some cases, are people of immense and outstanding talent, or are even regarded by 'philosophers' and 'historians of philosophy' alike as marginal, as mere journalists or dilettantes. I have not achieved my position, I am not a person of immense talent, and so I must be content for my work to be marginalised, or to be regarded as a journalist or a dilettante. But having stated what this book is to be - analytical Thomism, neither 'philosophy' nor 'history of phi­ losophy', but the best attempt I can make at what I consider to be philosophy - I can at least avoid those critics who will accuse me of blundering. It is not that I am trying to do both 'philosophy' and 'history of philosophy' in one book, foolishly and, of course, failing. I reject both notions - and I am trying to do something different. I am looking at how Aquinas discusses the question of whether there is an explanation for the world, distinct from itself, and the question of how the search for an explanation in general should proceed. I try to relate the two discussions and I hope that there will be material of interest and value for people who like to read Aquinas, or who like to speculate on the existence of God, or on the nature of the search for explanations. This is a modest aim, and I think I have in part achieved what I set out to do. It is for the critic to discuss how far I have succeeded, or how far what I sought to do is worth achieving. It is not for the critic to jump to the unreasoned conclusion that this work cannot be of any value because it is neither 'philosophy' nor the 'history of philosophy'. If a piece of work has value, it has it independently of current fashions of academic classification. This may sound an excessively arrogant claim, but I conceive that the tyranny of this division between 'philosophy' and 'history of philosophy', and the consequent persecution of those who do not choose to do either,

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has reached a point at which arrogant or harsh reactions are justified. I feel that in present circumstances I have some right to be harsh. It has happened that a tenured lecturer at a British university, an analytical Thomist, and thus neither a 'philosopher' nor a 'historian of philosophy', has found his freedom of association, his freedom of research and his freedom of teaching threatened or actually restricted, at least in part because he was neither a 'philosopher' nor a 'historian of philosophy'. He was driven into illness, depression and resigning his post, with long-term unemployment to look forward to. The matter is thus not of purely academic importance and thus justifies non-academic language in reacting to it. My proposal in writing this book, despite all my fears for the future in Britain of what I still think of as philosophy, is a modest one and a strictly scholarly or educative one: it is to communicate my understanding of St Thomas. This understanding, such as it is, is one which involves connex­ ions and parallels. Perhaps this is true of any kind of understanding: we can only understand in relation to what is familiar to us. What is familiar to me is the English-speaking analytical style of philosophy. Thus the book is directed to those who share this familiarity and wish to extend their philosophical knowledge into other periods and ways of thought. I do not mean to claim that we are limited in our understanding to what, in the writings of another period, finds a direct echo in our own times. It is true that at times we will bump up against ideas which cannot be immediately understood in contemporary terms, or in anything obviously related to these terms. Thank God for that- otherwise we would be shut within an intellectual prison formed by temporal provincialism of outlook. I believe that it is, at least sometimes, possible to make the imaginative leap necessary to get some kind of understanding of what at first seems absolutely alien. But once the leap has been made, if understanding is achieved, this understanding can be, as it were, justified retrospectively. And this retrospective justification consists, to a great extent, in arguing through from the familiar to the imaginatively grasped unfamiliar, and so discovering that the apparently alien can indeed be understood in terms of some analogical extension of the concepts and even prejudices we began with. I offer this understanding, such as it is, in the first place to those who are likely to understand even less than I do: that is, to those who have been reading medieval philosophy for less time than I have. It would be, I think, something of an impertinence for me to offer it to my equals, and still more to offer it to my betters. If my equals or betters happen to find by some chance something in this book that helps their understanding, I shall

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be very pleased and rather surprised. It is meant to be of use to students with some grasp of the usual concepts of analytical philosophy and some slight understanding of medieval philosophy. The whole is supposed to be of value to those interested in the philosophy of St Thomas; the first half may also be of interest to those concerned with the philosophy of science, while the second half concerns what is called the philosophy of religion. (Perhaps I may be permitted to object to this label as well. There is clearly a philosophy of religion, as there is a philosophy of art, and as there ought to be a philosophy devoted to any important human activity. But a philosophical study of the existence and nature of God is not a study of religion or of any human activity. Religion and the philosophical study of God have little in common except their object, God.) The particular object of this study are the Five Ways in which St Thomas offers to prove the existence of God, considered in the context of his theory of science. I do not think that the Five Ways have been properly studied in this context before, but to try to do this is a very natural move. 'Does God exist?' is, for St Thomas, a scientific question; indeed, it is the first substantive question of the new divine science he is seeking to establish. This can be thought of as a science that is Augustinian in 2 project and content, Aristotelian in structure and concept. In the context of such a science, what kind of a question is 'does God exist?' How do we answer such questions? What kind of understanding of the word 'God' is required for us even to start? What notion of existence is involved in giving answers to this question, and how does this notion relate to other notions of existence? How does a question like 'Does God exist?', and the methods used in answering it, relate to other similar questions in other sciences? How do they relate to the sorts of scientific questions we ask and the methods we prefer to use in answering them? Do we in fact, in our scientific endeavour, ever ask such questions as 'Does X exist?' How do all these considerations apply in the special case of God? To what extent do the Five Ways follow the methods of science which I will claim to find outlined in St Thomas's works? What kind of arguments are the Five Ways? How are they structured? How well do they work? In essence, this book is what I have been teaching students in the part dedicated to Aquinas in the medieval philosophy optional course in Glasgow over recent years. Those students have professed themselves happy with what I offered them, but there is always the feeling at the back of one's mind that one's own students are a captive audience. I put this work before the wider public in the hope that others will find it useful and thus, as it were, retrospectively justify my classroom practices over recent years.

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Some readers may be annoyed by the rhetorical, frivolous, and would­ be amusing nature of some parts of the book.3 They may ask, is this rhetorical style worthy of philosophy? Well, the performance I actually achieve probably will not, as it stands, be worthy of St Thomas, but I should like to record my view that the idea that rhetoric and philosophy are mutually exclusive is an error. St Thomas's own technical clarity and brevity is a mode of rhetoric, and they contribute admirably to his philosophy. His style, his rhetoric, is one of the features that makes him a greater man than either Scotus or Ockham. Many philosophers are great in spite of their style, but many others are great both in style and content. Wittgenstein springs to mind, but he is not the only one. It is probably in part the lucidity of Russell's style - i.e. his rhetoric - which helps us to appreciate him (justly) as a much greater philosopher than, say, Moore or Ayer. That may not be quite the point which critics may wish to make against the rhetoric I try to employ here. They will probably be irritated by the fact that I make fun of elements in the empiricist tradition and of important figures in the development of that tradition. The reason why I do this is that people in the empiricist tradition themselves make free use of the weapon of ridicule and it seems to me time that they got a dose of their own medicine. It is the commonest thing in the world for empiricist lecturers so to train their students that they giggle when­ ever they hear the word 'essence', or trot out the ancient joke about 4 'virtus dormitiva' whenever they hear talk of powers. This, I fear, is either ignorance or dishonesty. The lecturers in question probably know that some of the greatest philosophical minds have based their thought about the world on the concepts of essence or of power, and if they pretend that anyone who does so is eo ipso a suitable target for ridicule, they are being dishonest. If they do not know that some of the greatest philosophical minds upheld the concepts of essence and power, then they are so ignorant that I wonder what they are doing in a university at all. To teach young people to laugh at things which you dislike and which you know they don't understand is to my mind not the noblest possible work of an educator. Empiricist lecturers, who may very well not understand the concepts of essence and power themselves, can be sure that their students don't, because they will have taken very good care never to explain them, but only to present a caricature. If my opponents can laugh at me, can I not laugh at my opponents? Particularly since, thank God, I am in a minority. I need not fear that I am teaching my students to laugh at something they do not understand, which has never been presented properly to them; I know that however

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little care I take to present empiricist attitudes to them, however carica­ tured the picture of empiricism I present, my esteemed colleagues will make sure that my students do not remain in ignorance of the best case that can be made for empiricism. I admit, indeed, that I hope to use the weapon of artificially provoked giggles, but my aim is that by so doing we may come to an agreement to end its use once and for all. While only one side uses such a weapon, it will continue to be used. When both sides use it, when some of my colleagues find half their classes breaking out in uncontrollable mocking laughter whenever they hear the words 'constant conjunction', we may be able to reach a truce. Clearly, artificially provoked giggles on both sides are valueless in a philosophical discussion, and once we have reached a state where both sides are suffering from their use we can then perhaps agree to drop them and concentrate on the real points of debate. But while they are used only on one side, the side which uses them will be more successful and will, moreover, be convinced that it is winning the debate. So, curiously enough, those colleagues who may feel that I am using unfair weapons are in fact the object of my dearest concern. I fear that they have become so accustomed to using unfair weapons that they do not recognise them as unfair and valueless. My use of unfair weapons may wake them up to this fact, and they will then be able to stop using them. All being well, everyone will benefit from the process. NOTES 1. I have never properly understood the difference between an introduction and a preface. As far as I can make out, an introduction attempts to explain the oddities of the book, while a preface attempts to explain the oddities of the author. If this is correct, then 'introductory preface' is a good title for this section, in which the oddities of both are exposed, if not explained, pell-mell. 2. A fully developed account of this view of St Thomas's thought can be found in A. Macintyre, Whose Justice? Which Rationality? (London: Duckworth, 1988) and Three Rival Versions ofMoral Enquiry (London: Duckworth, 1990). 3. If you dislike this sort of thing, take a look at the last chapter, where the tone is about as frivolous as I can manage. If you can't bear it, then invest your time and money elsewhere. 4. For this venerable joke, see Chapter 13, pp. 188-90.

ACKNOWLEDGEMENTS

The help I have had in this work from innumerable people, none of whom is in any way responsible for any errors of fact, of argument or of taste that the book may contain, would be impossible to catalogue. My philosophical debt to Professor Geach and Professor Anscombe is immense, as any reader will notice, and I have done my best to make this clear in my notes and citations; but there is much that I owe them which cannot be acknowledged in that kind of detail. The first chapter, obviously, also owes a lot to the work of Alasdair Macintyre. I should like to mention my colleague from Glasgow, Professor Alexander Broadie, and two colleagues from Pamplona, Professor Alejandro Llano (especially for his getting me started on the theme of esse ut verum, being in the sense of the true: see Chapter 5, p. 66 n. 37) and Dr Jaime Nubiola. I also owe a good deal to innumerable students in both places, as well as in Mexico and in Rome, for whose sake and with whom I have been working on this theme. Three of these students stand out as having helped me particularly to clarify my thoughts: Niall Taylor, Craig Russell and Dr Maria Alvarez. I also owe a good deal to the authorities of the University of Glasgow, particularly my Head of Department, Ephraim Borowski, for granting me one term's paid leave after six years' service in the university and a longer period of unpaid study leave thereafter. As is perhaps well known, no-one in Glasgow has any technical right to any study leave at all. Without these leaves the book would not have been written. I wrote this book during this period of leave, a time when I was ill, depressed and distressed. The work I have done would have been wholly impossible, and not just uncongenial and difficult, without the help and kindness of many people. It is beyond my ability to thank them adequately. In the first place are my father and mother, who both died between the completion of the first draft and the reading of the proofs. I owe too an incalculable amount to my very dear friend and colleague Alexander Broadie, already mentioned, to Scott Meikle, also of the Glasgow depart­ ment, and to Dr John Divers of the University of Leeds. In addition I

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should like to thank, however inadequately, my friend, colleague and former student Eileen Reid, whose kindness and generosity to me in these difficult times was so great, and to which I never managed to respond in an appropriate way. I have to thank the people I have been living with over this period, for their forbearance: the residents of Dunreath Study Centre in Glasgow, the residents of Grandpont House, Oxford, and the residents of Residen­ cia Universitaria Monreal in Pamplona. The help I have received from all the members of the sub-faculty of philosophy in the University of Navarre has been immense. In Oxford I owe thanks to Corpus Christi College for offering me common-room rights during my stay. Among other people in Pamplona I wish to thank Andrew and Ruth Breeze for their kind hospitality, and I am especially grateful to Ruth for providing just the right degree of affectionate nagging to get me started and keep me moving on the bulk of the book. The material for this book was partly developed in and through classes and seminars I gave in the University of Navarre, as well as in the University of Glasgow, and the bulk of the book was written in Pamplona, where the University of Navarre is located. The book, if it has any merit, is thus yet another result of the magnificent relations which have been established between the philosophy departments in the two universities. These relations are mostly the fruit of the efforts of Professor Broadie. Perhaps no-one will expect this book to be very good, written as it is by a sick and perhaps embittered man. It is as good as I can make it and, as I have said, I have had many wise and good friends who have helped me make it better than it might have been. That the good is theirs and the bad is mine should be clearer even than it usually is in these cases.

COPYRIGHT PERMISSIONS

Some of the material published here, as part of a larger and more impor­ tant project, has previously been published elsewhere, when I thought it had sufficient importance on its own to interest the learned public. Material used in Chapter 1, dealing with the argument from authority, has appeared in my Introduction to Medieval Philosophy (Edinburgh: Edinburgh University Press, 1996) and in A. J. Hegarty (ed.), The Past and the Present: Problems of Understanding (Grandpont Papers No. l, Oxford, 1993). Material used in Chapters 2 and 3 has appeared in K. Jacobi (ed.), 'Rules for demonstration and rules for answering questions in Aquinas', Argu­ mentationstheorie: Scholastische Forschungen zu den logischen und semantis­ chen Regeln korrekten Folgerns (Leiden: E. J. Brill, 1993). Material used in Chapter 4 has appeared in I. Angellelli and A. D'Ors (eds), 'Significatio nominis in Aquinas', Estudios de la historia de la L6gica (Pamplona: Ediciones Eunate, 1990). Material used in Chapter 13 has appeared in 'Libertad y revocabilidad', Anuario Filos6fico, 1994/ 5, and is about to appear in a collection of Thomistic Papers edited by J. Haldane, under the title 'Voluntary and non-voluntary causality'. I am grateful for permission to re-use this material here.

1 •

THE S UMMA THEOLOGIAE AS A SUMMARY OF A DIVINE SCIENCE

The Summa Theologiae, Aquinas's uncompleted master-work, is, according to its title, a summary of the study of God. This study of God - the ologia - Aquinas himself usually called 'sacra doctrina', sacred teaching, or 'sacra scientia', sacred science. What these titles mean, and why such a study is necessary and opportune, is spelt out by Aquinas in the twelve articles of the first question of the Summa. The study of sacred teaching is necessary, he concludes, it is authentically a 'science', in the Aristotelian sense, it is a single science and it is a speculative science, though it has practical implications. It is superior to any other science, it is a kind of wisdom and it has God as its object. Like other sciences it proceeds by way of argumentation, and it depends on a correct interpretation of God's self­ revelation in Scripture. The first substantive question, which follows the methodological arti­ cles outlined above, is whether God exists, a question which is prefaced by a discussion of whether the existence of God is self-evident and whether it can be proved at all. Once these preliminary questions are settled, though, the first genuinely substantive discussion is, as I say, whether God exists. Is this a philosophical question at all? If so, why does it come here, at the beginning of a summary of theology, of the science of God, studied in and through God's own self-revelation? We need to answer these ques­ tions if we are to be confident that there is any interest of what we would call a philosophical kind in studying Aquinas on this point. To answer them we have to understand what Aquinas meant by a science. Aristotle defined 'episteme', the kind of knowledge that Latin Aris­ totelians called 'scie ntia', as 'definite knowledge through explanations'. 1 There is no doubt that St Thomas thought of this definition as correct, and that he used it out of respect for Aristotle's authority. 2 Both expressions just used are important here. Aquinas thought of this definition as correct, and he used it out of respe ct for Aristotle 's authority.

2

God and Explanations

Before we begin to examine what the definition implies for the study of Aquinas's Summa, and for the philosophical nature of the examination of the existence of God, we need to see how authority and truth were related in St Thomas's mind. For there can be little doubt that this feature of St Thomas's work is one which is extremely alien to the minds of present-day philosophers. Even though, as we shall see, St Thomas undoubtedly thought of the existence of God as what we would call a philosophical question- briefly, a question that can be answered correctly by the natural light of human reason alone, without recourse to the content of God's self-revelation he does not think it at all odd to appeal to the authority of the Bible putatively God's word - in answering it. 'ls there a God?' asks Aquinas and answers 'Apparently not'. He gives the two strongest arguments he can find for believing that there is no God, and then proceeds to explain why this appearance- that there is no God- is deceptive. The process is, as he calls it, argumentative. The arguments he gives against the position he is eventually to take up are the strongest he can find: this is his usual practice. In this case the arguments given continue to be the two most cogent arguments available. But he nevertheless appeals to authority: after giving the arguments against, the objections, as they are known, he at once begins his own response by quoting Scripture. There is a God, he says, because God's own name, as revealed by God, is 'I am who am'. 3 Aquinas was aware that someone who does not believe in God will scarcely be impressed by an alleged revelation. In his earlier summary, the Summa Contra Gentes, designed for the use of missionaries among Mus­ lims, he draws attention to the hopelessness of trying to use against 4 Muslims Scriptures that Muslims will not accept. Muslims, to be sure, believed in God then as they do now; and while it is, I believe, a matter of some dispute among Muslim doctors about whether Christians really believe in the one true God or not, Christian doctors, like St Thomas, normally have no difficulty in concluding that Muslims believe in the Christian God, though they combine it with what a Christian regards as an over-simple view of God's internal life. (Christians, according to Muslims, hold what must be either nonsensical or blasphemous beliefs about a Trinity within God. To what extent these beliefs mean that the Christians are deceiving themselves when they claim to believe in the one God of Abraham and the Prophets is, I think, a disputed question among Muslim theologians.) Was it that St Thomas, though acquainted with Muslims, did not know of the existence of atheists? Surely not. He knew enough history of ancient philosophy to refer to the Epicureans, and they held that there were no

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3

gods, or that if there were, they were only a part of the system of randomly generated worlds of which we also form a part.; He knew, surely, of the various philosophers and sophists labelled by their contemporaries as 'godless' (atheoi). He knew of the existence of the Emperor Frederick II Hohenstaufen - after all, he put to death at least one of Aquinas's family 6 - who was alleged to be an atheist. One who lived so much among the young would not have been more ignorant than was Adelard of Bath, whose young nephew, about a century before Aquinas's birth, told him that many of his contemporaries held that there was no God, or that God was identical with nature.7 Above all, if I may myself use an argument from authority, Aquinas believed in what he read in the Bible, and in the Book of Psalms it twice says 'The fool has said in his heart, there is no God' - a text, incidentally, quoted by St Thomas within the same question as the Five Ways.8 Thus we can be sure that Aquinas knew that his use of an argument from authority would fail to convince in arguing against an atheist, and that there were such people as atheists. Why, then, does he use this 9 argument? The simplest answer is, perhaps, that he always uses such arguments: they are an indispensable part of his argumentative procedure, his way of handling a question. Medieval learning in the universities at this period proceeded by way of the quaestio, the 'question' in a technical sense, that is the discussion for and against a given thesis. This might appear as a real debate, which might or might not be recorded and published, with more or less editorial input; or it might just mean the use of the quaestio-form in a published work. The latter is what we have in the Summa. In either case the question was announced and arguments for and against either side were put. In a live debate, these would be suggested by the students, and the master's assistant (the bachelor) would marshal them into some kind of order - sometimes, for example, playing off one against another and present them to the master. In a composed work in quaestio form the master would do this, more briefly, for himself. The master would then give his 'determination' - his magisterial solution - and then deal with whatever objections to his answer had not already been resolved. The form of the live debate was followed in a streamlined way in works composed in this form. In such a work, like the Summa, the more streamlined questions are at some remove from this process, though not wholly detached from it. But in either case, in a live debate or in a question-based textbook, there was always an appeal to authority, an authoritative text given at the outset of the 'determination', to support the line the master had decided to take.

4

God and Explanations

Clearly this way of proceeding is very foreign to our way of doing philosophy. While even today a typical article in a philosophy journal will contain a high proportion of footnotes that give references, the texts are seldom, it is claimed, being used in an authoritative way. They are typically, or notionally, being used to show that a given author did indeed hold the view that is being ascribed to him, or because the author cited has expressed a point better than the author citing can hope to do. Or at least, this is what we hold. And there seems little doubt that the medievals did not use authorities in this way. It is clear that the medievals took the fact that Aristotle said so-and-so to be a good reason for believing that so-and-so is the case. We do not believe this, or profess that we do not. All contemporary philosophers would at least say that they refuse to accept such an 'argument from authority'. Indeed, one sometimes comes across cases of contemporary authors in philosophy who are inclined to reject a thesis simply because it was said by some older philosopher who has been highly regarded by others. This last attitude is perhaps abnormal and should be dealt with by psychological rather than philosophical or histori­ cal investigation, but the existence of such an attitude highlights the contrast between the modern and the medieval. Given that we at least believe that we do not appeal to authorities in the way that medieval thinkers did, how should we react to their texts? There are two obvious ways of reacting, which I should wish to reject. The first is that of people like Bertrand Russell, who held that the use of the argument from authority shows that the medievals were not doing philosophy at all - or, more modestly, that the medievals were not doing what we call philosophy. This kind of reaction is unfortunate, since one who reacts in this way is unlikely to bother to read the medieval philoso­ phers and is thus unlikely to be able to learn anything from them. Another reaction is more intelligent, and less disastrous, but it still in the long run shows a failure of understanding. This is the reaction of those who are not put off by the use of the argument from authority and read on in the medieval philosophers. Those who do so soon discover that besides these, to us, unacceptable arguments from authority, there are other arguments which are, by our standards, very good indeed. This may lead them to read further, to become interested in medieval philosophy for the modern-style arguments that they can find in it; and they will thus become accustomed to skip the frequent arguments from authority, or to regard them as being of merely historical interest, as indicating the sources of the writer. In short, they will read the medieval writer as if he were a modern. This is a mistake. It is to fail to grasp what is distinctive in the medieval author. Read in this way, the medieval author will not be able to tell us

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5

anything very different from what a modern author would tell us, so we might as well read a modern author. We will not have our eyes opened by the shock of discovering a radically different way of thinking. Above all, we will not really have understood the authors we are studying. The modern who reacts in this way can find some justification even within medieval writings. It is often said that the most important parts of a conceptual framework are those that are never discussed, but taken for granted; but we are fortunate in that there were discussions among the medieval philosophers about the use of arguments from authority, despite the fact that arguments from authority formed an important part of their conceptual framework. The reason for these discussions is not that me­ dieval thinkers had any doubts about the value of authority in general, it is rather that arguments from authority had different values when the authority they were based on was a human authority, and when the authority they were based on was divine. Hence we find these discussions, one of which, perhaps the best known and most accessible, is to be found early on in Aquinas's Summa Theologiae, in the methodological first • question. 1 0 Aquinas says that the argument from a divine authority is the strongest argument of all, while the argument from a human authority is the weakest of all. This conclusion would be supported by most other medieval thinkers. The reason for this distinction is that human minds, even when honestly applied, are quite often mistaken and sometimes may be applied dishonestly, while God cannot be mistaken, cannot be deceived and cannot deceive. Hence 'Aristotle says such-and-such' is obviously of much less weight than 'God says such-and-such'. There are complications, of course. There is the question of the inter­ pretation of the authority: what exactly did Aristotle mean when he said that such-and-such was the case? Every statement needs to be interpreted in the correct way and this means, in practice, that it is rarely necessary to contradict an authority. Perhaps the text of Aristotle seems to say clearly that there are no centaurs, but even if you had seen a centaur, you need not say that Aristotle was wrong. You might argue that Aristotle meant something slightly different from the obvious sense of his words. No-one would be likely to worry about such a trivial case, of course, but the possibility always existed. This made it possible to blur in practice the important theoretical distinction which has been referred to, between the different strengths of divine and human authority. You could never straightforwardly contradict a thesis with divine authority behind it - that, the medievals considered, would have been unreasonable. (And given their premisses, they were surely right.) The argument from divine

6

God and Explanations

authority was stronger than any other. But what was the correct interpre­ tation of the statements made with divine authority? The answer to that question would commonly rest on human authority: the usual or obvious interpretation of Scripture had been made by some human being at some time. It might typically derive from St Augustine. But the argument from Augustine's authority, that this interpretation is in fact the correct interpretation of Scripture, is an argument from human authority. Thus, for example, the Bible tells us that King Solomon made a large round vessel for the Temple, a vessel which measured ten cubits across and thirty cubits round. u The natural interpretation of this passage implies that 1t, the ratio between the diameter of a circle and its circum­ ference, is three. Probably no figure respected as an authority by the medievals ever upheld this natural interpretation - certainly Augustine 12 would not have done so. But if any had upheld this interpretation, the human authority of that writer, which was an argument in favour of this interpretation, no matter how great his authority might be, would have been vulnerable to stronger arguments drawn from the science of geome­ try. The medievals knew that 1t is not three, and so would have claimed that the natural, literal interpretation of God's authoritative statement must in this case be rejected, despite any argument from human authority in favour of that interpretation. The interpretation of this passage in the Bible must be such that we take it to be giving only rough measurements. The argument from God's authority is the strongest of all: it is invulner­ able to any other argument. But the argument from the human authority, which might be brought in favour of the literal interpretation, is the weakest of all arguments: it is vulnerable to any other argument, let alone one as strong as a proof of geometry. It is thus possible for the modern reader to justify his ignoring argu­ ments from authority when he finds them in medieval writers on the grounds that the medievals did not take them very seriously either. The argument from human authority is, even to the medieval reader, the weakest of all; are modern philosophical readers of the medievals not justified in regarding this argument as being so weak as to be negligible? Moreover, modern philosophers probably do not believe in God, or even if they do, they may have very different ideas about what God may be supposed to have said, and how he said it, from the ideas the medievals had. Are modern philosophers not then entitled to believe that what the medievals thought of as the voice of God was in fact a merely human voice, the voice of lsaiah or St Paul? Are they not accordingly entitled to treat it as a human authority, the weakest argument, which modern philosophers regard as negligible?

The Summa The ologiae as a Summary ofa Divine Scie nce

7

This is a fair point, but there is a feature of Aquinas's discussion that should cast doubt over this typically modern reaction. When discussing the thesis that the argument from human authority is the weakest of all arguments, Aquinas cites the human authority ofBoethius in its support. 1 3 This should make us think. The argument from human authority, for Aquinas, though weak, is not negligible, as he is wining to cite it even in support of the weakness of arguments from human authority. We can sum up the difference between the medieval and modern attitudes to authority as follows. For the moderns the voice of authority is no argument at all; for the medievals it was an argument. Admittedly it was the weakest argument of all, so that any other argument was stronger, but it was none the less an argument. You needed another argument to refute it, before you could ignore it. The moderns think they can just ignore it without any other argument. For the medievals, if Aristotle said that centaurs did not exist, and you had no stronger reason for believing that centaurs did exist - for example, the evidence of your own senses - then you had good reason for believing that centaurs did not exist. There was an authoritative statement, so the question 'Do centaurs exist?' was not purely an open one. Since an authority had spoken on the subject, the burden of proof and the form of the question were established. It is therefore a mistake for modern readers to understand the medieval position, that the argument from authority is the weakest of all, as a polite under-statement of their own position, that the argument from authority is no argument at all. This is not what the medievals meant: they meant what they said, that the argument from authority was an argument, even though any other form of argument was stronger. The medieval attitude to authority, then, was different from ours. Do we just have to accept this as a brute fact, or can we come to have some imaginative grasp of what it meant to have this different attitude? Can we even come to understand it, to see that it is at least not totally unreasonable or superstitious, as some modern philosophers might tend to regard it? The best way to go about this task of understanding, I think, is to try to see how our own attitude to authority is itself not self-evidently correct, but stands in need of an explanation, an explanation which is rather hard to find. I think that this self-examination - this instilling into the reader of the philosophy of the past a feeling of strangeness about his or her own unexamined beliefs - is of the greatest value in coming to understand the past, and also is one of the elements of greatest educational value in the study of past beliefs.

8

God and Explanations

It would perhaps be permissible to say that the main attempt of modern philosophy has been to give a firm foundation to knowledge. At the back of our minds all of us moderns have the idea that all our knowledge derives either from experience or from self-evidently true principles. 14 This notion derives from Descartes and his heirs, from the typically modern (i.e. post-Cartesian) project of founding all knowledge on true, certain and indubitable principles. Now, that which we believe because we have been told it - that which we believe on authority - though it may be true, is far from being certain or indubitable, at least by post-Cartesian standards. But we should try to clear our minds of this cant, and consider the matter calmly. If we do, we should be able to realise that most of what we believe we believe because we have been told it: we believe it on authority. Now we should be clear that on our own principles we have no right to believe this. As a result, it is our own attitude to authority that looks odd and in need of explanation, not that of the medievals. It is in fact entirely reasonable to believe what we are told. Most of what we are told is true, and when false, it is usually in itself unimportant, or false in unimportant ways. Moreover, when it is false, we can often correct it - usually, let me add, by being willing to learn from better authorities. To restrict our actions to what we can do on the basis of our own experience and on deduction from self-evident principles would be to restrict our action unreasonably. Also, it is clearly unreasonable to believe what we are told while also believing that we have no right to believe what we are told, which is, in fact, roughly what the modern position is. If we do believe what we are told, as we do - if we do trust in authority, as we do - then we should recognise the fact. Thus, it is reasonable to trust in authority. It is unreasonable to trust in authority and pretend that we don't. We can even go further: it is simply unreasonable not to trust in authority. How do we decide what is reasonable and unreasonable? In particular, how does a modern philosopher come to the conclusion that it is unrea­ sonable to trust in authority? The answer must be, by applying his standards of reasonableness. The crucial question which follows on from this is, how do modern philosophers acquire their standards of reason­ ableness? I am sorry to say - or rather, I am really rather pleased and amused to say - that standards of reasonableness are acquired on authority. When we were children, we were brought up under authority. This teaching to a great extent made us what we are: it introduced us into our community, into our family, into our nation, into the human race (considered as a social phenomenon) as full and active members. There are two things to be

The Summa Theologiae as a Summary of a Divine Science

9

noticed here. The first is that we needed to be introduced - we could not have attained this status on our own. We were made into full members of the club. We had, no doubt, a right to be made members of the club, in virtue of our birth into this species; but without our upbringing, and the use of authority in this upbringing, this right would never have been exercised. The other thing to notice is that this community is not just the community of those now living. My great-grandparents were dead before I was born, but part of what I am I owe to them, physically, psychologically and culturally. Despite all the generation gaps that exist or have existed, what we learn on the authority of our parents about who we are, about what to believe or do, is substantially the same as what they learnt from theirs. The differences which we know to exist between the attitudes of different generations are only noticeable because they stand out against a background of agreement. This is what it is for a culture to exist. It is passed on by authority, and it continues through time by tradition; what is passed on by the authority of a parent generation is mostly passed on by the authority of the child generation to its children. But nowadays we never speak of this. Tradition, like authority, is seen as very much a second-best: something to be superseded, something, perhaps, that is necessary in childhood, or in past centuries, but not at all to be welcomed by adults of today. Instead, we say, we should trust in reason. To see through the fallacy involved in this popular slogan we should notice the fact that if we are to trust in reason we need to know what the standards of reasonableness are. We do in fact have standards of reason­ ableness, as the little child does not. That is why we have to use tradition and authority in teaching children: there can be no dispute about this. But what is seldom noticed nowadays is that we have standards of reasonable­ ness because we have been initiated into our culture by means of tradition and authority. Once we have the standards of reasonableness, we can challenge this or that part of traditional authoritative teaching in the name of these standards of reasonableness: that is, we can challenge doubtful parts of the tradition in the name of more basic parts - perhaps, in the name of the tradition as a whole. But we cannot use part of the tradition to challenge the tradition as a whole: we cannot claim that it is unreason­ able to hold to any tradition, when the very standards of reasonableness which we are employing in this challenge only come to us from tradition. The unreasonableness of such a claim is like the unreasonableness of the following sentence: 'It is impossible for there to be an intelligible sentence written in the English language.'

10

God and Explanations

It should be noticed that what I am myself doing here is precisely issuing a challenge to one part of our culture in the name of the standards of reasonableness that form another part of it. I am challenging our modern attitude to tradition, because it is not reasonable, and I make the challenge in the name of the standards of reasonableness that I hold as the fruit of tradition. This seems itself a reasonable challenge. What I could not do is challenge our modern culture as a whole for being unreasonable as a whole, because my standards of reasonableness derive from the tradition of this culture, with a little help from reflection on ancient and medieval culture. The modern opposition between tradition and reason is as unreasonable as a universal attack on the unreasonableness of modern culture as a whole would be. It would, indeed, be possible to maintain that it is not only unrea­ sonable not to trust in authority: it is also impossible. There is a rabbinical story of a Gentile who came to Rabbi Hillel, asking to be taught the Law. But, he went on, he only wanted to be taught the written Law, not the oral Law; that is, he wanted to be able to read God's written word for himself, without the glosses put on it by the wisdom of the teachers of Israel. The story is of Rabbi Hillel, who was renowned for his kindness and courtesy, so the interview did not end at that point, as it might well have done if the Gentile had gone to another rabbi. Rabbi Hillel began by writing out the Hebrew alphabet on a sheet of paper and telling the Gentile to come back once he had mastered it. The Gentile, nonplussed, replied that he recognised the Hebrew alphabet, and admitted that he would have to master it before he could be taught the written Law, but he didn't know which letter was which. 'Ah,' replied the Rabbi, 'so you want me to tell you which 5 letter is which?' 1 In the same way we need to be taught our very language, on authority, if we are to be able to systematise even our own experience sufficiently to make it into anything that could be a foun­ dation of other knowledge, or to grasp even self-evident truths. Even if trust in authority is necessary, it is still hard for us, in our culture, to appreciate the fact. To help us, we can perhaps draw attention to a number of features of even our society and culture in which authority and tradition are paramount, even though they are not generally recog­ nised. Religion is still mostly a traditional affair, even though many theologians do not seem to realise it, or even deny it. A couple of cases currently in point are the ordination of women and allowing priests to marry. The best argument against women's becoming priests is that this has never been done: that restricting the priesthood to men is something which the Christian Church has done in a traditional faithfulness to the

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inscrutable will of God, as first revealed in Christ's choice of the apostles. Theoretical arguments based on a supposed appropriateness of males for the priesthood certainly exist, but they seem weak. If the argument from authority and from tradition is not accepted, there seem few compelling reasons for continuing to do as has been done up to now; but if authority and tradition are recognised, the reason they give is entirely compelling. The same point is true of the marrying of priests. Journalists, commenta­ tors and even theologians nowadays fail to distinguish between the ques­ tion of whether we should allow or even encourage married men to become priests, and the question of whether we should allow those who have become priests to get married afterwards. This failure to distinguish is based on a failure to recognise the importance of tradition. Different Christian communities, of undeniable apostolic tradition, have over the centuries had different opinions, for different reasons, of whether or not one should allow married men to become priests. No Christian commu­ nity of unquestioned apostolic tradition has ever allowed priests to marry after becoming priests. The tradition is clear and strong, but we seem nowadays incapable of recognising it or regarding it as important. Once it is recognised, other arguments have to be evaluated in terms of whether they are strong enough to overthrow the argument from authority and tradition. The question is not an open one, which we are called upon to answer out of our own heads, as if for the first time. Religious tradition, however poorly understood by religious believers or commentators these days, provides a clear reflection of the attitudes of earlier ages. But there is another parallel: we can compare the pre-modern attitude to the tradition of learning to modern traditions of science. For Plato and Aristotle, to become a learned person, a philosopher, is a process that involves admitting the authority of the philosophical tradi­ tion, involves accepting the attitudes, beliefs, behaviour and standards of that community. These attitudes include attitudes to the history of that community and hence attitudes to the tradition itself. Like the traditional reasonableness of the human race, and like religious traditions, such a tradition has its own standards, which are also accepted on the authority of tradition. These can be used to judge individual parts of the tradition, or individual features of the present state of the tradition in this genera­ tion, which may be found to be defective in one way or another. But of course the tradition as a whole cannot be judged as not up to standard by the standards of that tradition. It could only be so judged by outside standards: and it is not at all surprising that those with different standards should judge it badly. But they are likely to misunderstand it, as much as we misunderstand the medievals. There are no neutral standards.

12

God and Explanations

We can, if we wish, compare the tradition of learning as understood by Plato and Aristotle with the tradition of the scientific community in our own day. This is perhaps the nearest we come in our society to a commu­ nity based on a genuine tradition. The truth about this is disguised from us by the rhetoric used by journalists, philosophers of science and even by scientists themselves about 'reason', but in fact the scientific commu­ nity is a traditional one, based on authority. Those who wish to enter it have to give up whatever other beliefs, standards and attitudes they may have had, and adopt, on authority, the new standards of the scientific tradition. They cannot hope to justify the beliefs, attitudes and standards of science by means of beliefs, attitudes and standards which they bring from outside. Among these attitudes, it is important to notice, is an attitude towards the scientific tradition itself: an attitude to the history, or rather the story of science. The story of the scientific tradition which the newcomer must accept is not a detailed history of everything that any scientist has ever done in the name of science: it is a genuine tradition, a story which picks out only those things which are to be believed at the present day, or have in some way contributed to what is believed at the present day. This is very much the same as the way in which newcomers into a religious tradition are not told about all the heresies there have been: they are told the Faith. Once newcomers have established themselves in the scientific community, they may use the standards of science to correct this or that current or recently past view, but they cannot use the standards of science to overthrow science. It is indeed, no coincidence that while we do not find appeals being made to authority in articles in philosophy journals, we do find them in scientific journals. The average paper in Nature, as Geach has pointed out, contains far more references to past work than does the average article in the Summa Theologiae. 1 6 It will be said that the two cases are not on all fours: that the results cited in an article in Nature are, at least in principle, repeatable, while the authorities cited in the Summa are not. This would involve a confusion. Clearly, the authorities cited in the Summa do not refer to repeatable experiments, since theology is not an experimental science. But they do refer to repeatable reasonings. The experiments are unrepeatable because there are no experiments; but the reasoning is repeatable, which means that it is open to question and open to revision. Notice that there is no contradiction between the attitude of such post-modern contemporaries of ours as Quine and the attitude of St Thomas, while both attitudes are strongly at odds with the modernist, foundationalist conception of science and philosophy. Quine thinks we should regard any proposition which we

The Summa The ologiae as a Summary of a Divine Science

13

hold as being in principle revisable. But this revisability in principle requires that we should hold the rest of our belief system steady while we revise the belief in question, and make whatever subsequent adjustments to the system that thus become necessary. The rest of the belief system can be used as lever and fulcrum to overthrow any given belief because we are able to treat the rest of the belief system as fixed. There is no bedrock truth, but at any time some beliefs must be treated as if they were fixed. Often they will be methodological beliefs: and for this reason St Thomas begins the Summa by setting out his methodology. In the same way some at least of our standards of reasonableness must be received from authority and held fixed if we are to overthrow others. In the same way, within science, our trust in older scientific authors and in the validity of their experimental methodology must be held fixed if we are to believe that their results are even in principle repeatable. To sum up, then, if St Thomas frequently cites Aristotle, or St Augustine, it is because, as I said at the beginning of this discussion, he both has respect for their authority and thinks that what they say is correct. St Thomas's trust in his authorities is not a blind trust, like that which the Pythagoreans are said to have had in the ipse dixit of their master: it is a rational trust. It is not just that St Thomas has this trust - he is able to expect his readers to have it too. His readers are to be students and masters in the schools, people who have a share in the tradition which he is developing. This seems alien to modern philosophy, and indeed it is, but it is not alien to the practice of modern science, and it should not be alien to the philosophy of those who, like Quine, are struggling to throw off the dogmas of modernism, in either its rationalistic or empiricist forms. I have often found, when leafing through university prospectuses, that philosophy is recommended to the prospective student by some phrase such as 'Philosophy teaches you to challenge accepted wisdom and ques­ tion everything' . 1 7 My only comment is, who says so? Is this phrase not a part of accepted wisdom? Should it not then be questioned? In fact, the student who questions everything (and you always get a couple each year) is no more likely to be successful in philosophy than he is in science, engineering or law. Philosophy teaches you to question the things that philosophers usually regard as questionable, no more and no less. There is no doubt that the exclusion of the student who wishes to raise the sceptical doubt in every single philosophy class is a necessary condition of progress in this as in every other form oflearning. That in St Thomas's day the exclusions practised were different from ours should raise no difficulty. That these exclusions were more extensive than ours is a difference of degree and not of kind. Some may feel that any loss that was

14

God and Explanations

incurred through the breadth of medieval exclusions was more than made up for by the speed and intensity of the development that these exclusions made possible. NOTES I. 2. 3. 4. 5. 6. 7. 8. 9.

10. I I. 12.

13. 14.

15.

16. 17.

See Aristotle's Posterior Analytics, I, 2, 72a!0--72b4. See Commentary on the Posterior Analytics, L.I, 1.4, n. 32. Summa Theologiae, I, q. 2, a. 3, sed contra; Exodus, 3 . 14. See Summa Contra Gentes, I, 2. The Epicureans were called atheists in the ancient world, and there seems little doubt that one of Aristotle's objections to Democritus was that he left no room for the divine in his system. He was also, I believe, alleged to be the son of Beelzebub, so one doesn't know how seriously this kind of accusation was meant or taken. Adelard of Bath, Questiones naturales, q. 76, edited by M. Miiller, in Beitriige zur Geschichte und Theologie des Mittelalters, vol. 3 1 , fasc. 2 (Miinster in Westfalen: Aschendorff, 1934), p. 69. Psalms, 14 [13]: I, and 53 [52]: I . St Thomas quotes the latter in Summa Theologiae, I, q. 2 a. I . M y discussion o f the argument from authority, i n this chapter, and o f the figure o f Augustine, derives in great part from A. Macintyre, Whose Justice? Which Rationality? (London: Duckworth, 1988) and Three Rival Versions ofMoral Enquiry (London: Duckworth, 1990). The argument from authority is discussed in a more polemic context in my 'Arguments from authority', The Past and the Present: Problems of Understanding (Oxford: Grandpont Papers, 1993), pp. 25-35, and in a fuller historical context in my Introduction to Medieval Philosophy (Edinburgh: Edinburgh University Press, 1996) pp. 16---44. Summa Theologiae, I, q. I , a. 8. I Kings, 7:23. Augustine pointed out, in discussing to what extent the first two chapters of Genesis need be taken literally, that God's purpose in giving us this book was to make us Christians, not astronomers. His own interpretation of the seven days of Creation was so non-literal that it made no reference to any periods of time whatsoever. Summa Theologiae I, q. I, a. 8, second objection: 'Locus ab auctoritate est infirmissimus, secundum Boethium.' This thesis is dealt with excellently by P. T. Geach in 'Knowledge and beliefin human testimony', in The Past and the Present: Problems of Understanding (Oxford: Grandpont Papers, 1993), pp. 1 5-24. The historical background is dealt with by Macintyre, in Three Rival Versions. To add another argument from authority, Pope John Paul II clearly takes a similar view in Crossing the Threshold of Hope (London: Collins, 1994). I believe I found this story in the notes to the Yale Judaica Series edition of The Sayings of the Fathers, with reference to a quotation attributed to Ben Bag-Bag, but I cannot now be sure. The editors conjectured that the Gentile protagonist of this story was so impressed by Hillel's answer that he eventually converted to Judaism and himself became a rabbi, taking the name written BGBG, because he was the man who had needed to be told the difference between B and G, beth and gimel. Geach, 'Knowledge and belief in human testimony', pp. 1 5-24. Compare, for example, the sections on philosophy in the Glasgow University undergraduate prospectuses for 1993--4 and 1994--5.

2 •

THE NATURE OF SCIENCE IN MEDIEVAL THOUGHT

I have tried to make out what St Thomas thought he was doing in the Summa Theologiae, and to some extent I have tried to make out why he did it. Also I have tried to see why the attempt is not a wholly pointless one. My aim is to elucidate the first substantive question he asks in this study, and to do this it was necessary to examine what kind of a study it is. St Thomas was trying to construct what he thought of as a science: that is, a systematic body of knowledge, a part of wisdom, as he says, out of all the materials available to him. Among the materials available to him are the authorities, and, as we have seen in the previous chapter, it came naturally to a medieval thinker to begin his scientific investigations with an examination of material derived from authority, as it comes natural to us in our ordinary occupations and thoughts. The two authorities whom Aquinas most respects and most uses are Aristotle and St Augustine. The choice of these two is not arbitrary. St Augustine in some sense provided the model, Aristotle the detailed method. The striking feature of the work of St Augustine is his attempt at harmonisation, at reconciliation. This is recognised by any encyclopedia, which will explain Augustine's achievement as that of bringing about a synthesis between Christian and pagan wisdom. But there is more to be said. The synthesis, the harmony, which Augustine first sought was a harmony between his thought and his life. This harmony was something he had been seeking over half a lifetime, but which he had only achieved through making the submission of humility required for his conversion. The well-known story of the moment of his conversion is extremely relevant here, as in the discussion of many other stages of Augustine's thought. The great scholar was only able to harmonise his life and his thought through taking the half-overheard inconsequential babblings of a child as a voice from Heaven. It was this that enabled his will to respond to his intellect and to achieve the harmony oflife that he had been seeking, the lack of which harmony had been torturing him for years.

16

God and Explanations

From this fact stems Augustine's belief that in some sense the under­ standing of faith precedes the understanding of reason: a paradoxical claim, since it seems rather obvious that while God gives reason to all, he gives faith only to some. But for Augustine reason on its own will wander blindly, incapable of understanding even its own truths, unless the rea­ soner submits to the radical conversion to the faith which Augustine himself had undergone, a conversion which threw new light on all his previous learning. At last, he thought, he had achieved an understanding in which his life and his thought could be united. This meant a wholesale re-appraisal of his previous thought. At last, he felt, he could understand Plato correctly, better even than Plato had done. He could at last see why and how Plato had been right (when he had been right) and why and how he had been wrong (when he had been wrong). All human learning could now be seen in the light of faith: it could either be pressed into service to illuminate the understanding of faith, or be definitively rejected as incon­ sistent with the faith. 1 This view of Augustine's developed into a tradition, which enlightened the succeeding centuries. Harmonisation, reconciliation and synthesis became the ideals pursued at the University of Paris, as they had been at the Augustinian-inspired schools which had preceded it. In Aquinas's time this ideal was facing its greatest challenge. The slow, argumentative discussion and development of this unified tradition of human and divine learning had been thrown into turmoil by the re-appearance in the West of the works of Aristotle. Aristotle was already, to the early medievals, a name to which respect was due, an auctor, one with authority. The neo-Platonic philosophy which Augustine had made the basis of the human part of his synthesis of wisdom had already, before Augustine's time, adopted Aristotle's logic to provide it with a structure. Moreover, some of Aristotle's fundamental metaphysical cate­ gories had become known in the West through the writings of Boethius, and had provided a framework for the development of theological specu­ lation about the inner life of God and God's relation to the world. For this reason, the newly discovered writings of Aristotle could not merely be brushed off as unimportant, as trivial and erroneous philosophis­ ing. Moreover, the general philosophy of Aristotle fitted far better, unsur­ prisingly, with the logic of Aristotle which the medievals were used to working with, than it did with the general neo-Platonic philosophy adopted by Augustine. Above all, Aristotle's work presented a fully developed, coherent view of the world as a whole and of the human being's place in it, which was in important respects inconsistent with the view upheld by the Augustinian synthesis. It naturally presented itself as a rival to that view.

The Nature of Science in Medieval Thought

17

Moreover, the Augustinian position itself demanded that it should be able to give some account of this rival. The aim of the Augustinian project was a synthesis of all human wisdom. Any proposition put forward for inclusion in that synthesis, in principle, could be judged in the light of that wisdom. If true, it could be incorporated; if false, it could be shown to be false and rejected. It looked, at this time, as if the philosophy of Aristotle could neither be incorporated nor rejected. Medieval thinkers were all too prone to accuse their opponents of teaching that there could be two separate kinds of truth, a religious truth and a truth of reason. Any thinker who did so hold would have been guilty of abandoning the Augustinian project (as well as the Aristotelian logic which structured it), and it is in fact hard to pin down any medieval thinker as actually having made such a radical claim. But we do have, from the period, the notes of an anonymous student who was confused enough by the problems of the age to note, 'The above [Aristotelian] propositions are true in the Faculty of Arts, but not in the Faculty of Divinity'. 2 It was into this world, facing this problem, that Aquinas came - and he did not shirk the problem. He attempted to establish the framework for, or to make the first step in, creating a new complete synthesis, a synthesis of the Augustinian tradition and the wisdom of Aristotle. The joint importance of these two authors to Aquinas can be brought out in a crude but effective way: in the index of a recent edition of the Summa theologiae, references to both run to over thirty columns, while references to their nearest rival, St Leo, run to only ten. We could say, putting it crudely, that the aim and spirit of St Thomas's project was Augustinian. Aquinas was seeking an understanding which a Christian could live by, and the holiness of his own life may be held by some to have confirmed that he achieved this aim. But in many ways the structure was Aristotelian. Thus in the case at issue, of the discussion of the nature of science: Aquinas is seeking for wisdom, wherever it may be found, and if the beginning of wisdom is the fear of the Lord,3 a necessary preliminary is to establish that the Lord is God. But this wisdom is understood by Aquinas as being an Aristotelian science, a science of the kind for which Aristotle laid down principles in his Posterior Analytics and which he tried to develop in his Metaphysics. The Posterior Analytics is a curious work. It seems to present as the ideal science a system of deductive inferences from stated axioms. A body of knowledge on these lines was well known for centuries in Euclid's geome­ try. We may pause to marvel at Aristotle's perspicuity in laying down rules for what was not to be achieved until several generations after his death,

18

God and Explanations

but our principal reaction is usually one of impatience. Surely no other body of knowledge is, or could be, articulated in such a way. If no other body of knowledge can be an Aristotelian science, then the notion of an Aristo­ telian science is of very little interest to us. Moreover, there is a very apparent contradiction between Aristotle's account of science in the Posterior Analytics and his actual practice in the Metaphysics, the Physics, the Ethics or the De Anima, to say nothing of his practice in his magisterial works on natural history. We find nothing in these that is parallel to the structure of Euclid's geometry. Instead, Aristotle examines common experience, as found either in folk-wisdom or in the writings of the poets or of other philosophers; or, where common experience is lacking, he makes his own observations. He then brings arguments, his own or those of others, against the obvious or usual explanations of these experiences. If these objections can be rejected, as they often are, the common view is held to stand, perhaps suitably modified by criticism, or perhaps with a more developed explanation provided by Aristotle himself. And then on to the next topic. We can make of this what we will. One bizarre, but possible, reaction, might be to reject all of Aristotle's substantive work for not fitting in with his professed methodology. Another, less bizarre reaction, which actually occurred among later scholastics, would be to reduce all of Aristotle's work to the structure suggested in the Posterior Analytics. This, as I say, has actually been done; it is an operation which has in great part been responsible for the bad name that Aristotelian scholasticism still has in some quarters. Another reaction is to reject the Posterior Analytics, a course which has been taken by authors as recent, and as favourable to Aristotle, as G. E. M. Anscombe. 4 5 A sounder reaction is one which has more recently gained favour. This is to observe that what Aristotle is recommending in the Posterior Analytics is not what he thinks he is doing in the rest ofhis works. In the Posterior Analytics Aristotle is laying down what he takes to be the correct articulation of a body of knowledge once achieved: it has nothing to do with the way in which that body of knowledge is acquired. The model in the Posterior Analytics is just that, a model, an ideal. It bears the same relation to what Aristotle does in the rest of his works as a management consultant's flow-chart of the operations and relations aimed at in the operation of a work-space to the processes of designing and constructing an office layout, and hiring and training the staff who will carry out the operations and bear these relations. It is not, in fact, a theory of finding out truths, which, crudely speaking, is what we think a theory of science should be; it is a theory of the relations which should be seen to exist between truths once found out.

The Nature ofScie nce in Me die val Thought

19

Whether the theory in the Posterior Analytics is in fact a good account of the relations between the truths of a science once found out, is a disputable question, which will be examined shortly. What is important to notice here is that Aristotle should not be criticised for doing badly something he never set out to do - giving an an account of finding out and that therefore neither should St Thomas be criticised for imitating him. We might observe, though, that even if Aristotle's account of the structure of a completed science is correct, we may fault him for failing to draw our attention to the difference between this account and an account of the way in which we can find out. Certainly we can criticise him for not giving us a sufficient account of finding out. He gives us no theory of science in the modern sense, no theory of finding out, though he held such a theory, at least tacitly, as we can see by examining his actual practice. This criticism can also be made against St Thomas, but with less force; in his Comme ntary on the Posterior Analytics St Thomas does give more explicit attention than his master to the process of finding out. Nevertheless, we can still criticise St Thomas for a lack of explicitness in distinguishing between a theory of a completed science and a theory of finding out. And we also need to look at whether the theory of the ideal, completed, model science is accurate or not. If it is not accurate, then, we might think, just in so far as St Thomas succeeds in making his new divine science like the model, he will be failing to produce a good science. In the same way, the management consultant's flow-charts may be perfectly well constructed, but they may not help us to achieve what we need to achieve. This reaction would be an exaggerated one. St Thomas would not have thought that what he left at the end of the Summa The ologiae , even if that work had been completed, would have conformed to the model in any detail. The construction of a divine science is not work for one individual. Even in geometry, Euclid's achievement was to put together in a coherent structure the work of innumerable predecessors. Aristotle was proud of being the first to produce a science oflogic, but it was clearly not complete; he knew it was not complete, and St Thomas, who himself provided some interesting developments and corrections of Aristotle's logic, did not take it to be complete. St Thomas would have held that no science, with the possible exception of geometry, was at his time complete: all required more development. The more developed a science was, the more one could hope to see in it the features of the model; and St Thomas does often draw attention to the way in which Aristotle's work often does match the model in important respects. We can expect, then, to find St Thomas holding that in so far as his work is complete it will match the model, but

20

God and Explanations

the fact that the model is based on a misunderstanding, if it is a fact, need not mean that Aquinas's work, when valuable, is so only by mistake. Clearly, though, some examination of the model is in order. Crudely, the model is articulated in a top-down, deductive manner, though any science which has been built up to fit it will in fact have been developed in a bottom-up, inductive or dialectic manner. The process of finding out starts with individuals, and therefore with the contingent, but it eventually reaches the universal and the necessary. A completed science, therefore, has to do with the universal, and it consists of necessary 6 truths. The conception of 'necessity' involved here need not be a very strong one: often it seems to be equivalent to no more than 'universality' or 'everlastingness'. But, for an Aristotelian, there are, strictly speaking, no universal and everlasting contingent truths: there is nothing that just happens to be always the case. The necessity involved in a completed science is at least natural necessity. Though it need not be as strong as logical or mathematical necessity, it is never as weak as pure contingent universality or everlastingness, as what just happens to be always or everywhere the case. It is important to recognise, though, that for a theistic Aristotelian such as Aquinas, all the natural necessities in the world, though genuine necessities, are in a sense conditional necessities, and in that sense are infected with contingency. Aquinas thought, with Aristotle, that the uniform circular motions that had been observed in the heavenly bodies were necessary, both in the sense that they continue for ever, and in the sense that given that there are the heavens that there are, the movements could not have been otherwise. But it was a debatable point whether there could not have been more or fewer heavenly bodies and, for Aquinas, it was indisputably true that the world, with its heavenly bodies, might not have existed at all. What Aristotle would have thought on this question is again disputable, but the medieval thinkers who assimilated Aristotle were unequivocal on this question. The whole question of the necessity of the truths of a completed science is yet more complicated by an observation of Aquinas that the link from effect to cause is necessary, while the link from cause to effect is contin­ gent.7 His point is that this individual effect could not have come to be without this cause - since had it come about any other way we would not count it as 'this individual effect', but as another, qualitatively indistin­ guishable, individual effect - while what in fact caused this effect, in a different overall context, could have had a different effect. Since in the realm of physics, for example, many of the explanatory links in a science

The Nature of Science in Medieval Thought

21

will consist of the efficient causality of which he is speaking here, 8 the distinction between the dialectical, inductive and contingent process of building up a science, and the necessary, deductive nature of the science once constructed, seems doubly threatened, in that the links of bottom­ up, effect-to-cause reasoning employed in the construction of a science, which should be contingent according to the theory, appear to be neces­ sary; while the links of top-down, cause-to-effect reasoning that will be found in a completed science, which should be necessary, appear to be contingent. The problem is intractable. We can perhaps make a start by pointing out that there is no reason to suppose that every useful, interesting or important piece of knowledge which we acquire in building up a science will eventually find its place in the completed science. Certainly, not every necessary connection which we make use of in building up a science will have to form a part of the completed science.9 While it is clear that St Thomas, following Aristotle, regards what he calls a 'science', a completed science, understood as we have said, as a paradigm of knowledge, it is also clear that there is plenty of important knowledge which fits this paradigm only very imperfectly. We need to take a step back, and try to understand, first, why their notion of 'science' is important to Aristotle and to Aquinas, and how one science is related to another in the overall structure of speculative wisdom. Plato, before Aristotle, had drawn attention to the difference between knowledge and true belief, and the distinction may go further back than that, to Socrates. 1 0 Clearly, we are unwilling to grant that a person knows this or that fact simply because she or he very strongly believes it. We are all acquainted with strong, unfounded belief, and it may very well be false. Even when it happens to be true, that it is true is contingent. We expect someone who claims to know some fact to be able back the claim up with reasons, as Plato said in the Meno. We do not, in general, accept that people know that so-and-so is the case, even if so-and-so is the case, unless they have not only reasons, but the right reasons, for claiming that so-and-so is the case. The tag that Plato uses in the Meno to mark out the difference between true belief and knowledge - that knowledge is 'tied down by calculation of reasons' - comes close to Aristotle's own definition of episteme, science, already mentioned, that it is 'definite knowledge through reasons' or 'through explanations'. (The more classical translation, 'certain knowl­ edge through causes', is ambiguous with regard to the 'certain', and too restrictive in modern philosophical English as regards 'causes'. 'Cause' in modern philosophical English tends to mean what Aristotle called the

22

God and Explanations

'efficient cause' or 'efficient mode of explanation', an explanation in terms of how a thing came about. Aristotle famously also recognises explanation in terms of matter - of what a thing is made of; in terms of form - of what makes what it's made of into what it is; and in terms of end - of what it's for). Aristotle and, following him, St Thomas, regard science as the fullest kind of knowledge because the reasons given in science are the right reasons. This appears to mean the following. Let us suppose, to take an example of Aristotle's own which St Thomas discusses, that there is an 11 eclipse of the moon. I can know this by observation. I may go further, and discover, building up a science, that there is an eclipse of the moon because the earth is obstructing the light of the sun. Is this all I need to know? Are my reasons for knowing that there is an eclipse of the moon, and that the Earth is obstructing the light of the sun, as good as they might be? Aristotle holds that they are not. In this case I know that p - that there is an eclipse of the moon - and I know that q - that the Earth is obstructing the light of the sun. I also know that p-be cause-q, that there is an eclipse of the moon because the earth is obstructing the light of the sun. Aristotle clearly thinks that until the order of reasons for my knowledge matches the order of reasons for reality, my knowledge is still imperfect. His ideal is that I should know that p because I know that q, that I should know that there is an eclipse of the moon because I know that the earth is obstructing the light of the sun. To know that the sun is obstructing the light of the sun because I know that there is an eclipse of the moon is an imperfect kind of knowledge, one that falls short of complete science. The example, though Aristotle's own, is in some ways badly chosen, and makes the whole idea of Aristotelian science look more absurd than it need. Aristotle's science is not concerned with individual occurrences: he does not, therefore, have to hold that scientific knowledge is a better way to know whether the moon is in fact at present eclipsed than is looking at the moon, though the way he sets up the example seems to suggest this. What he does have to hold is that if l know that at times the sun's light is obstructed by the earth, and that therefore there are, at those times, eclipses of the moon, I have a better reason for holding that there are at times eclipses of the moon than I would have through having noticed the Moon eclipsed from time to time; and, a fortiori, it is to have a better and more complete kind of knowledge than if I only know that the earth sometimes obstructs the light of the sun because I know that the moon is sometimes eclipsed. This may still seem a little odd: surely, some would say, I could not have better warrant for believing that the moon is eclipsed than my having

The Nature ofScience in Medieval Thought

23

seen the moon eclipsed? I think this is a mistake. I have seen rainbows, and water on tarmac roads on hot days. But I do not believe that there is a physical object called a rainbow, and I do not believe that there is more water on tarmac roads on hot days than on cool rainy days. My having observed eclipses is far from being the best reason I could have for believing that there are physical processes called 'eclipses'. If I am to believe this, I need stronger warrant, which brings my belief in eclipses into an organised system of explanation of how the physical world works. It is because I have no such warrant for a belief in a physical object called the rainbow, or for the existence of water on the road on a hot day, that in the end I come to disbelieve in their existence. Put in this context, Aristotle's position does not look quite so absurd. Moreover, it draws attention to the fact that each piece of knowledge in a scientific system is only as good as the system of science as a whole that supports it. If the best reason I can have for holding that the moon is eclipsed is my knowledge that the earth is obstructing the light of the sun, then it matters a great deal what is the best reason I can have for holding that the earth is obstructing the light of the sun. And the best reason here would be to do with some optical thesis about the way light travels in straight lines, and some astronomical thesis about the relative movements and positions of earth, moon and sun. This explains why the notion of science is important to Aristotle and to Aquinas. A body of science, if achieved, would provide one with the best foundation or warrant for a knowledge-claim that one could have. In the same way, the best foundation or warrant for a claim to know some theorem in Euclid is to be able to demonstrate it from Euclid's axioms. This connects with the next point of explanation. Each 'science' - each articulated body of explanatory knowledge, within a given subject-matter - should, like Euclid's geometry, be traceable back to certain axioms. These will be truths which are taken as basic for the science in question. They will be few and of universal scope. Thus, certain definitions and statements about properties of bodies as such will form the axioms of physics, certain definitions and statements about properties of living beings will form the axioms of biology, and so on for each individual science. It is important to notice that these axioms are taken as fundamen­ tal for the purposes of the science concerned. It is not the task of a science to prove its own axioms; what a science has to do is to draw out the reasonings from them. The axioms can be, and usually are, the conclusions of a more fundamental science: indeed, it is the question of what conclu­ sions are used as the basis for what science that settles the question of which science is more fundamental than which. Thus, strictly, no science

24

God and Explanations

is complete until all sciences are complete. It is hardly to be wondered at that the practice of Aristotle and St Thomas is so different from what they lay down in their model. If there were no reasonable process of construct­ ing a science which differed markedly from the structure laid down for how a completed science should be, there would be no possibility of starting - nothing could be known until everything were known. Although the above remarks may have done something to make the notion of Aristotelian science less thoroughly alien to our conceptions, less absurd, and therefore to that extent more acceptable, little has been done in direct defence of the notion. In fact, little can be done. I shall continue by drawing attention to some other features of the articulation of science which have their effect in the theory of how a science is to be built up, in the hope ofshowing at least that the theory of a completed science, though perhaps in this day and age indefensible overall, is at least comprehensible, and is not likely to give rise to great distortions in the building up of a science in detail. Key elements in the structure of a completed science are definitions. Definitions, for Aristotle and St Thomas, are always real rather than nominal definitions: they are always definitions of what the thing is, not definitions of what the word is. I notice that the distinction between the two is well brought out by the difference between, say, the Oxford English Dictionary and the Spanish Diccionario de la Real Academia. The English dictionary seeks to tell you how the word is used, and thus tell you what it applies to. The Spanish dictionary tells you what the thing is that the word applies to, and thus tells you how the word should be used. Both kinds of dictionary are useful in different ways, and since the word often means what the thing is which the word is used to apply to, the definitions often coincide. But there is an important notional difference at stake. A definition, then, for St Thomas, 1 2 is a formula of words expressing what a thing is. This, too, is likely to be misunderstood. For Aquinas, as for Aristotle, what a thing is is its true essence - what explains why it is the way it is. Thus, to choose a geometrical example, a circle is a plain figure bounded by a line called the circumference, which is such that all straight lines drawn to the circumference from a single point within it are all of equal length one to another. 1 3 This definition explains why a circle has all the features that it has. Equally, a human being is a rational animal; this definition, if it is both true and complete, will explain why human beings have the features which they essentially have. Time is the meas­ urement of movement, according to before and after. And so on. We will see later something of how these definitions are arrived at, in the stage of constructing a science. What is important here is to see what

The Nature of Science in Medieval Thought

25

is their role in a complete science. They are the key steps in its structure. It is clear that very little about the real world of moving bodies follows from those first principles of physics, those axioms mentioned above, which define what it is to be a physical entity subject to change. For those first principles to give reasons for what bodies actually do in the world, we have to add information about what bodies there are in the world and what these bodies are. This information is given by the definitions. I have just said 'what bodies there are' and 'what these bodies are', as if distin­ guishing the question of existence from the question of essence. It is natural to make such a distinction, and indeed it is made by both Aristotle and St Thomas, but it is important to notice that in their minds they are linked. If there are no planets, for example, then there is no 'what' for the planets to be: there is no essence, and therefore no definition, of what does not exist. 14 Equally, to say that the planets have no essence is to say that the planets do not exist, perhaps in the sense that rainbows do not exist; or, if they do exist, that they are mere coincidental phenomena, as we might say the weather is, and not appropriate studies of science. Here we come up against the harder questions which I have been dodging. Do not the limits imposed on the notion of science by Aristotle and St Thomas make it too restricted to be interesting? Indeed, do they not make it too restricted to have any application at all outside the realms of Euclidean geometry and its offshoot, Ptolemaic astronomy? (And since it turns out that Ptolemaic astronomy is false in large and important respects, this is a limited field indeed.) It is true that for St Thomas and Aristotle it seems that there could be no such science as what we call the science of meteorology. For these two authors the phenomena which make up the weather are just that, phenom­ ena, coincidental existents which obey no laws, which have no essence. This is not just ignorance on their part: the fact that we can point to regularities and laws in the weather would probably make no difference to them. The weather, and the entities that make it up, are not substances, things with their own nature or essence, and therefore there can be no unchanging truths about them. 1 5 For it is a well-known fact that Aristotelian science is about eternal, or at least everlasting and unchanging truths. 1 6 This follows from the 'neces­ sity' of the truths of science, which again follows from the aim of science to provide as good a reason for one's beliefs as one could possibly have. We cannot have a better reason for our belief that p than that it could not possibly be that not-p. Hence science aims at necessary truths. And what is necessary is always the case, since what is sometimes not the case can be not the case. Hence science is of unchanging truths.

26

God and Explanations

Aristotle, indeed, may even have held that what is always the case is necessary, that there is nothing that just happens to go on for ever, though 7 the attribution of this view of Aristotle is disputed. 1 But at this point we strike a difference with Aquinas. Part of the reason for holding that Aristotle believed that what is always the case is necessary, is the view that he believed in the principle of plenitude: that whatever can happen, at some time does happen. (There is an interesting parallel with the view of necessity and possibility which is nowadays called extreme modal realism, that whatever can happen does happen somewhere, in some real but non-actual 'possible world'.) Thus, whatever can stop happening, at some time does stop; thus, whatever always happens, happens of necessity. Aristotle was thus committed to a view, which we find him frequently 8 mocked for, of the eternity of, for example, animal species. 1 Since it was clear that it is necessary for kittens to come from cats, in some sense of 'necessary', Aristotle seems to have thought that the series of cats produc­ ing kittens must have existed from eternity. But it is also arguable that all Aristotle meant by 'the eternity of species' was that a natural kind has no tendency to stop existing, as such, while the individuals of a given natural kind generally do have such a tendency. Be that as it may, this is where we begin to see important differences between Aristotle and St Thomas. The latter's metaphysics is creationist; the former's is not. St Thomas believed that the world at some time came into existence and will at some time cease; Aristotle did not. Thus St Thomas cannot have held the principle of plenitude in the form that, it is alleged, Aristotle may have held it. That form of the principle depends on the existence of infinite time in which all real possibilities might be actualised. St Thomas did not believe in an infinite extent of time. St Thomas thus could not glibly identify the necessary, in any sense, with what always happens. Moreover, he had given some thought to the question of mules. Mules had been discussed by Aristotle, but he did not see the metaphysical implications. St Thomas did see the metaphysical 9 implications, and accepted them. 1 A mule is born from a horse. and a donkey, but is neither a horse nor a donkey. It is recognisably a third equine species, another natural kind of the horse family :_ though an imperfect one, as one cannot breed mules from mules. Even if one grants that horses and donkeys might have existed for ever, as far back as the world exists breeding and giving birth to the next generation of horses or donkeys, this cannot be true of mules. It must be the case that species can come into existence; and it must have been obvious to St Thomas that if one took the trouble to keep horses and donkeys apart, that species would cease to exist as well.

The Nature ofScience in Medieval Thought

27

St Thomas, then, does not identify the necessary with what always happens. Nor, given his creationist metaphysics, could he hold that anything created could be in any very strong sense a necessary existent, that it could not have not existed. 20 Be that as it may, there seems to be room in St Thomas's theory for a genuinely necessary science of the contingent. If this is so, he might be able to admit what we call the science of meteorology as a genuine science, in his sense - albeit one which is still in process of completion and not yet completed. The key text for this is the introduction to his Commentary on the Nicomachean Ethics of Aristotle. The subject-matter of ethics, in general, is human action. But human actions are individual, contingent, temporal and temporary. How then can they be the subject-matter of an Aristotelian science, which has to do with the necessary and everlasting? The answer given is to distinguish between a broader and a narrower sense of 'subject-matter'. It is true that in general the subject-matter of ethics is human actions. Human actions form its 'material object', to use scholastic jargon. But clearly this is going to be in any case an insufficient account. Other studies, such as history, or, in our day, psychology and sociology, also study human actions. What is it that distinguishes ethics from these? The distinguishing mark of any science is its 'formal object': the precise aspect under which its material object is studied. Clearly the formal object of ethics will have to do with human actions in so far as they are good or bad. St Thomas prefers to say that the formal object of ethics is the ordering of human actions towards the end of human life, or, since one and the same science deals with contraries,2 1 the extent to which human actions fail to be ordered to their end. There are clearly good reasons for holding that this ordering will be in the relevant sense necessary and unchanging. The end of human life is what human beings are for; and it is a plausible claim, as well as one which Aristotle and St Thomas would certainly endorse, that what human beings are for depends on the very nature which is expressed by the definition of the human being. It is arguable that this end, what human beings are for, does not, will not and cannot change so long as human beings exist. The manner in which human actions are directed towards or away from this end will also be radically unchangeable. Not, of course, that there may not be more or less wicked periods of history, but such a historical study falls outside the scope of ethics. All ethics has to tell us is, for example, that if there are periods in which such-and-such is done, they will be more wicked periods, to the extent that such actions are directed away from their proper end. This kind of thought is not wholly alien to us, though some people nowadays may find its application to the field of ethics troublesome.

28

God and Explanations

(Though in this context it is worth remarking that distinguished contem­ porary moral philosophers in the English-speaking world, at least until very recently, have been willing to take the alleged special 'universal­ isablity' of moral judgements as a mark of the special subject-matter of ethics.) But in other cases we can see the application. Science, we tend to think, in some sense prescinds from the here and the now and aims at timeless validity. Token-reflexive expressions such as 'here', 'now', 'I', 'you', 'yesterday', 'tomorrow', 'over there', have no place in what we would call a scientific discourse. This point is made clearly in Frege's essay, 'The Thought', 22 and Quine lays particular stress on it in, for example, Word and Object. 23 Even experimental results - which are of course achieved in a particular time, in a particular place, by a particular scientist or group of scientists - are supposed to be intrinsically repeatable, and in so far as they fall short of repeatability or are suspected of falling short of repeatability, are to that extent ruled out as being serious scientific discourse. Thus this kind of Aristotelian thought is far from being wholly alien to us. There can, then, be a true Aristotelian science of the apparently wholly contingent field of human actions, provided that the formal object of study is sufficiently clearly delimited to provide us with the necessity and unchang­ ingness that we need. The same point can be made about physics. For Aristotle and St Thomas, most of the movements of terrestrial bodies are in themselves wholly contingent. But there is a necessary and unchanging ordering that they have, which we can make the object of scientific study. Aquinas will also allow us to express ourselves more loosely. We usually say that the subject-matter of natural philosophy is that which is subject to change, rather than speaking more strictly and saying it is 'the ordering of natural things'; and in the same way we can say that the subject-matter of moral philosophy is human performance in its ordering to its end, or human beings in so far as they act voluntarily for an end.24 There are, indeed, more general considerations which help us to the same end. For Aquinas the per accidens, that which is composite or which exists coincidentally (see below, pp. 63-5), cannot properly be the object of scientific study.25 But everything that is per accidens, that exists coinci­ dentally, is made up of the per se, that which exists in its own right.26 And the per se is a proper object of scientific study. Thus there is nothing in the world that falls outside the scope of scientific study, even though not every description which is true of this or that part of the world sufficiently determines it as a possible object of a scientific study. A passage early on in the Summa, later repeated, 27 gives a general epistemological and logical background to this point. The way we

The Nature ofScience in Me die val Thought

29

understand the world need not be the way the world is, in the following sense: our structures of thought need not exactly match the world's structures. To say that the cat is on the mat we need to use a number of words which cannot be all pronounced at once, though if the cat and the mat are not present all together, in the appropriate relation, the sentence will not be true. The relation between the cat and the mat is a spatial relation, while the relation between the words 'cat' and 'mat' is, in spoken English, a temporal one. In written English the relationship between the words is a spatial one, but not the same spatial relationship as that which exists between the cat and the mat. We do not need to perform typo­ graphical prodigies such as:

cat

mat

Meanwhile, in Latin there is no particular spatial or temporal relationship that need exist between the words, and so on. This, as Aquinas says, does not mean that our thought is false. Our thought would be false if it represente d the world as being otherwise than the way the world is. It does not become false merely by itse lf be ing 28 otherwise than the way the world is. This point, which is true of our thought in general, is true also of our scientific thought. It represents, in whatever way, necessary and unchanging aspects of a changing and contingent reality. According to Aquinas, the changeableness and contin­ gency is made up of the coincidence of many strands of unchangeable and necessary causality or explanation. Our scientific thought does not mis­ represent the world: it represents it to us in the only way that we can understand. That some descriptions that are true of the world are not descriptions relative to which we can understand the world adequately, or articulate our understanding, is not surprising. Understanding every­ thing does not mean understanding everything about everything. When we read a book we do not need to know how many characters it contains, and when we examine the world of moving bodies we do not need to know how many moving bodies happen to have collided in the last half-hour between here and the end of the road. The conclusion we can perhaps draw is that the Aristotelian notion of science employed by St Thomas is neither so bizarre nor so restricted as at first sight appeared. We can understand the desire for achieving a science which will be in some sense universal, necessary, and unchanging, and we can see that this desire will not rule out the possibility of genuine scientific knowledge of the contingent and changing world. Neither Aristotle nor St Thomas are partisans of the kind of a priori science that

God and Explanations

30

made the young Kant think he could make an accurate guess at the physical and indeed moral characteristics of the presumed inhabitants of 29 other planets. NOTES 1 . For a defence of this view of the Augustinian project, see A. Macintyre, Three Rival Versions of Moral Inquiry (London: Duckworth, 1990). 2. See Macintyre, Three Rival Versions, pp. 1 07-8. 3 . 'Timor Domini initium sapientiae', Psalms, 1 1 1 [ 1 10): 10. 4. See G. E. M. Anscombe, essay on 'Aristotle', in G. E. M. Anscombe and P. T. Geach, Three Philosophers (Oxford: Blackwell, 198 1 ), p. 6. 5 . See typically the view expounded by J. Barnes, in his translation ofand commentary on Aristotle 's Posterior Analytics (Oxford: Clarendon, 1975). 6. Commentary on the Metaphysics, L.II, 1 .4, n. 323: 'Scientia non est de singularibus' . See also Summa Theologiae, II-II, q. 47, a. Sc. 7. See for example, Commentary on the Perihermeneias, L.I, 1 . 14, n. 1 86; cf. below, Chapter 6, note 45. 8. See Chapter 6 below, note 48. 9. For example, it is surely important to know, as Kripke as pointed out, and as Aquinas also believes, that who you are depends on who your parents are. Thus Socrates is necessarily the son of Sophroniscus and Phaenarete. But such a particular truth as 'Socrates is necessarily the son of Sophroniscus and Phaenarete', though it is both true and necessarily true, and though we might well use it as an example in building up a science of human identity, will have no place in the universal science of human identity once completed, which will ignore all such particular truths. 10. Cf. Plato, Meno, 98a4. 1 1 . See Commentary on the Posterior Analytics, L.I, I. I . 1 2 . Commentary o n the Metaphysics, L.VII, I . I I , 1 528: 'Definitio vero significat quid est res'; and 1 . 12, n. 1 537: 'Definitio enim ratio ratio significans quod quid est.' 13. Euclid, Elements, Book I , section I , defir.ition 1 5 . 1 4 . Commentary o n the Posterior Analytics, L.I, lect. 2 , n . 1 7 . 'Non entium enim non sunt definitiones.' 1 5 . See, for example, Commentary on the Metaphysics, L. VI, 1 .2, 1 172-6: 'scientia non speculat de ente per accidens' ('Science does not examine the coincidentally existent'). 16. See, for example, Commentary on the Posterior Analytics, L.I, 1 .4, n. 32; L.I, 1.16, n. 1 36; L.I, 1 .42, nn. 376-8. 17. See below, Chapter 1 1 , p. 1 57, and the references there made to the work ofKnuuttila and Llano. 1 8 . Though I cannot understand how there can be those who mock Aristotle and yet take seriously the extreme modal realism of, for example, D. Lewis, as an opponent which needs facing. Any difference between them seems to me to count in Aristotle's favour: for example, if he reduces necessity to what always happens, he has as restricted an ideology as Lewis and a far more restricted ontology. 19. See, for example, Summa Theologiae, I, q. 73, a. I, ad 3 . 2 0 . O n this, a discussion i n the first part o f the Summa i s relevant: o n the power o f God (Summa Theologiae, I, q. 25). In article five Aquinas asks whether God could have made things other than he did, and answers that he could; in article six he claims that at least in some sense God could have made things better than he did. The whole discussion takes place against the background of article three, which discusses the almighty power of God, in which St Thomas claims that the only limits to the power of God are logical ones. But on this see the interesting discussion by P. T. Geach, in 'Omnipotence', in Providence and Evil (Cambridge: Cambridge University Press, 1977), pp. 3-28. 2 1 . Commentary on the Physics, L.VIII, 1 .2, n. 977: 'Scientia, licet sit una contrariorum . . . '. 22. In P. F. Strawson (ed.), Philosophical Logic (Oxford: Oxford University Press, 1967). 23. W. V. 0. Quine, Word and Object (Cambridge: M.I.T. Press, 1960); see, for example, p. 142. 24. Commenta�y on the Nicomachean Ethics, L.I, I . I , n. 3. 25. See above, note 1 5 . 26. Commentary o n the Metaphysics, Book V , lectio 9 ; and cf. Chapter 5 below, pp. 63-5 .

The Nature ofScience in Me die val Thought

31

27. Summa Theologiae, I , q. 1 3 , a. 1 2, a d 1 and I q . 8 5 , a . 1 , a d 1 . 28. See P . T . Geach, 'God's relation to the world,' in Logic Matters (Oxford: Blackwell, 1981). 29. In his Allgemeine Naturgeschichte und Theorie des Himmels (Universal Natural History and Theory of the Heavens), Third Part, in Kant 's Werke (Berlin: Reimer, 1 9 1 0), pp. 3 5 1--68. It is worth reading this just to see what Kant meant by 'dogmatic slumbers', and to realise that the influence of Hume was in at least one case highly positive.

3 •

THE ROLE OF QUESTIONS IN THE ARTICULATION OF SCIENCE

The last chapter was an attempt to expound intelligibly, if not entirely to vindicate, the notion of scientific study which St Thomas derived from Aristotle, and to show that such a notion is not so foreign to our own conceptions of inquiry as we might at first sight think. If the ideal of science which they held is one we can, after all, with certain reservations subscribe to, we can also look to them for guidance in a task which is perhaps of more interest to us than it seems to have been to them: a search for an understanding of the processes of coming to acquire a structured body of knowledge, and of the rules that govern that process. If we grant that the Aristotelian/Thomistic scientific project is not so alien to us as it at first appeared, we need to look at the way in which this project is to be carried out. Here, as has been said, their explicit writings on science are not of much help, since these writings give us an account of the relationships between truths once grasped, an account of what is understood by one who has achieved perfect scientific knowledge. What we want is rather an account of how we can begin to build up such a science. Clearly, we can get some hints from the way in which our two authors in fact go to work. In Aristotle's case, this involves the gathering of common opinions, the dialectical challenging of them, and their accep­ tance, modification or rejection. St Thomas follows a similar dialectical pattern with the (to my mind rather slight) difference that he has a body of authoritative writings and opinions which he wishes to reconcile with one another and with his own thought, in so far as possible. But Aquinas at least occasionally gives us some kind of explicit account of the building up of a science, and, in any case, some of the considerations relevant to the structuring of a completed science once possessed are relevant also to the building up of a science. Chief among these is the role attributed to questions. Knowledge, for St Thomas, and afortiori the structured knowledge through explanations

The Role ofQuestions in the Articulation ofScie nce

33

in which science consists, is a series of answers to questions. To ask a 1 question is to want to know, and to know is to be able to answer a question. It is true that the very idea of a completed Aristotelian science means that St Thomas is more interested in what is communicated by the knowledge­ able teacher to the ignorant student, than he is in how the investigator finds out for himself. But even the perennial reference to the teacher, which appears to match the top-down, deductive nature of Aristotelian science, admits of some reference to the process ofinvestigation. For while St Thomas holds that the top-down deductive structure of a completed science is in some sense more intelligible in its own right, the student can best come to understand it by going through a process which follows the 2 process of the discoverer or investigator. Even when it is a question of a student's learning rather than an investigator's discoveries, St Thomas has an interest in making the student find out, as if for himself, rather than allowing him to be told. Be that as it may, however we are to think of the way in which we come to understand the answers to questions, the first thing to grasp is what kinds of questions are scientific questions, and how they are related. St Thomas, following Aristotle very closely, uses two pairs of criteria to establish a four-fold division. The first pair of criteria consists in a distinction between what we could call questions of fact and questions of explanation. It is one thing to ask whether such-and-such is the case, another to ask why it is the case. The other pair is a distinction between questions about a thing and questions about a proposition. We thus have questions about the fact of a thing, and about the fact of a proposition; and questions about the explanation of a thing, and about the explanation of a proposition. The question about the fact of a thing is an est?, does it exist? The question about the fact of a proposition is quia? is it the case? The question about the explanation of a thing is quid est?, what is it? And the question 3 about the explanation of a proposition is propte r quid? why is it the case? These four scientific questions can be set out conveniently in the following diagram:

Fact

Thing Proposition

Explanation

A n es t

Q u i d es t

Quia

Prop ter q u i d

34

God and Explanations

Clearly there is an order of priority among these questions. We need to discover the answers to questions of fact before we can hope to discover the answers to questions of explanation. 4 This is indeed St Thomas's practice: we find him asking 'Does God exist?', as the first substantive question of the Summa, before looking at the question of what God is. (Though as a matter of fact he goes on to remark that in the case of God the best we can hope for is an answer to the question of what God is not. 5 ) But this, of course, is in the context of the construction of a science. St Thomas manages to give us the very strong impression that in a complete science, worked deductively from the top down, the answers to questions of explanation are given first and the answers to questions of fact are conclusions from the explanation. The picture he puts across is that the best possible reason we could have for believing that p is a good grasp of the reason why p is the case: the best reason we could have for believing that x exists is a good grasp of the real essence of x. This kind of science looks chimerical. To return to the example used in the last chapter, it looks as if the best reason we could have for believing that the moon is eclipsed is our belief that the earth is obstructing the light of the sun; indeed, it looks as if St Thomas wants us to hold that until we do know that the earth is obstructing the light of the sun, and that for this reason the moon is eclipsed, our knowledge that there is an eclipse does not count as scientific. Or to use an example that both St Thomas and Aristotle give for the answering of an an est? question, we do not know that thunder exists unless we know that fire is extinguished in clouds, on 6 the (admittedly false, as St Thomas insists ) supposition that thunder is the quenching of fire in the clouds. Though we would be hesitant about admitting so much, we would surely agree that our knowledge that the moon is eclipsed does not form a part of a body of science unless it can be put in some intelligible relation with its explanation, and we might even agree that our knowledge that thunder exists requires tying down to some kind of explanation for us to be able to know what we really mean when we say thunder exists. Compare again the question, 'Does the rainbow exist?' Of course in one sense it does, and in another sense it doesn't: a scientific answer to this question will establish what the rainbow is in order to be able to tell us in what sense the rainbow exists and in what sense it doesn't. Even the picture of the completed science which St Thomas gives us here, which seem to invert the natural order of the questions, is not so bizarre as at first sight it appears. In any case, there is explicit commentary in St Thomas about the order to be followed in answering the questions, when we are constructing a science. This order is the natural order

The Role ofQuestions in the Articulation of Science

35

suggested above: first, questions of fact, and only then questions of . 7 exp1anat1on. We should remember that the answer to the question quid est? is supposed to be a definition, a real definition, a statement of the real essence of the thing in question. It is for this reason, above all, that this question has to follow on after the question an est? That which does not really exist will have no essence, and therefore no definition which really expresses that essence. In modern terms we might want to say that we need to have some grasp of what x is before we can have a chance of discovering whether or not x exists. St Thomas sometimes talks in this way,8 but he normally prefers to restrict the notion of 'what a thing is' in such a way that there is no answer to 'what is it?' when the thing in question does not exist. Clearly, though, he needs to give some account of the knowledge which we need to have previous to any attempt to answer a question an est? and in fact he gives us a very full and detailed account, in terms of his notion of significatio nominis. Before we can begin to ask whether X exists, we need to have some knowledge of what the word 'X' means. NOTES I . On questions, see Chapter 6 below, pp. 80---93: Commentary on the Posterior Analytics, L.II, I . 1 , n. 409. 2. On teaching and learning, see Summa Theologiae I, q. 1 17, a. le. 3 . Perhaps the most important single passage for this doctrine is to be found in Commentary on the Posterior Analytics, L.II, 1 . 1 nn. 408-12: 408. There are four things which are asked about, i.e. that, why, whether it is, and what it is (quia, propter quid, si est, quid est). To these four everything that can be asked about or known can be reduced. (Though in Topics I he divides questions or problems into four another way, all of which kinds of question are included in one of the above kinds, namely the question that. But there he is talking only about the questions which are disputed dialectically.) 409. Then when he says 'For when we ask whether', etc., he makes clear what is meant by the aforementioned questions. First he deals with the composite questions. To make these clear we have to consider that it should be possible to know, and hence ask about, only a statement, since knowledge is only of the truth, and truth is signified only by a statement. But as it is said in De lnterpretatione II, there are two ways of forming a statement. In one way it is formed from a noun and a verb without anything added, as when we say 'a man is', in the other way, when there is some third expression besides, as when we say 'a man is white'. A question can be formed which refers either to the first kind of statement, in which case it is a simple question; or to the second kind, in which case it will be a composite kind of question. This kind of question is also called a 'plural' question, because it asks about the composition of two things. About this kind of statement two kinds of question can be formed. One is, is this which is said true? Aristotle first sets this out by saying that we ask whether a certain thing is this or that. This is in some way plural: for we take two things, one of which is the subject and the other the predicate, as for example when we ask whether the sun is failing in an eclipse or not, or whether man is an animal or not. This is what is called asking that (quia). This is not because the word that is the mark or sign of asking a question, but because we are asking in order to know that it is so. The evidence for this is that when we find this out by means of a proof, we stop asking; and if we had known this at the beginning, we would not have asked whether it was so. For inquiry does not cease until the attainment of what was sought for. And so, since

36

God and Explanations the question we were asking, whether this is this, ceases when we attain the answer, it is so, it is clear what is sought by this kind of question. 410. Then when he says, 'For when we know', etc., he shows us the kind of question that follows from this, which is also plural. He says that when we know that it is so, we ask why (propter quid) it is so. For example, when we know that the sun is failing in an eclipse, or that the earth is moving in an earthquake, we ask why the sun is failing, or why the earth is moving. And we ask this with a plural question. 41 1 . Then when he says, 'There is another way', etc., he shows us two other kinds of question, which are not plural but simple. He says that we ask some questions which are different from the two kinds mentioned, in that they are not plural - as when we ask whether there is a centaur or not. For here we simply ask about a centaur whether it is (an est), not whether it is this, for example, white or not. And just as, when we know that this is that, we ask why, so when we know about something whether it simply is, we ask what it is (quid est), for example, what is God? or what is man? These are all the things that we ask: and when we find out, we are said to know. 412. Then when he says 'For what we are asking when we ask', etc., he shows the relation between the above questions and the middle term . . . . On the first, we must notice that of the above four questions - two plural, two not - he links the first two of each kind together, i.e. the question that and the question whether it is. He says that when we ask about that thi:s is this, or when we ask about something whether it is, we are just asking whether any middle term of what we are asking is to be found or not. This is not something which is said as such in the question. For when I ask whether the sun is eclipsed, or whether there is a man, I do not ask, as far as the form of the question is concerned, whether there is any middle term by which I can demonstrate that the sun is eclipsed or that there is a man. Nevertheless, if the sun is eclipsed, or there is a man, it follows that there is some middle term for me to find to demonstrate what I am asking about. For there are no questions asked about what is immediately known: even though they are true, they have no middle term. This is because such things are obvious, and do not fall under any question. So then, it follows that the person who asks whether this is this, or whether this is simply, is asking whether there is a middle term. For what is being asked in the question whether it is, or the question that, is whether there is something that is a middle term. This is because the middle term is the description of that about which we are asking whether it is this, or simply is, as we shall say below. But it is not being asked for qua middle term.

4 5. 6. 7.

See Commentary on the Posterior analytics L.I, 1 .2, n. 17, and L.11, I . I , n. 410. Summa Theo/ogiae, I, q. 3, preamble. Commentary on the Posterior Analytics, L.11, 1 .7, n. 477. Commentary on the Posterior Analytics, L.11, 1 .7, n. 474. 8. De ente et essentia, 3.

4 •

THE SIGNIFICATION OF A NAME

The last chapter dealt with the crucial role of the asking and answering of questions in the medieval theory of the building up of a science. It also argued for the pre-eminence, among questions, of those of the form 'Does X exist?' or 'Do X's exist?'. Since, as we have remarked, the first substantial question in St Thomas's new science of God is 'Does God exist?', it is clear he is sticking very closely to what his theory prescribes here. But as St Thomas himself is very well aware, no answer to the question 'Do X's exist?' will be forthcoming, and no solid start can be made in attempting to answer a question, without a grasp of what the word 'X' means. St Thomas gives us a very full account of what it is for a word to mean something, and how we can come to find out what it means, and applies these reflections to the special case of the word 'God'. The notion of significatio n omin is, the signification or meaning of a name, plays an important role in St Thomas's account of answers to existential questions, what we have called questions about the fact of a thing; i.e. of how one can come to answer the question an est?, is there such a thing? The principal context in which he explains this notion is his discussion about the language we use about God, and 1 how it signifies. But he also uses it explicitly in his discussion of the 2 logical preambles to the existence of God, and in general discussions of how we can come to give answers to questions of the form 'Does X exist?'. It is worth our while to examine these doctrines closely, in order to see that while the doctrine seems to have been developed to deal with the rather special case of God, it is not a mere ad hoc: it has a clear rationale and a possibility of being applied far more widely. In order to see this more clearly I shall suggest parallels with well­ known doctrines and discussions of Frege and Kripke, which were developed well outside any theological context and are of very wide application.

38

God and Explanations We read in the Commentary on the Posterior Analytics: Before one knows whether something exists, one cannot strictly speaking know what it is: for there are no definitions of what does not exist. Hence the question, does it exist, is prior to the question, what is it. But one cannot prove that something exists, unless one understands what its name signifies.'3

Some of the notions involved here are clarified later: For there is no quiddity or essence of that which does not exist: so no-one can know what something that does not exist is. But one can know the signification of the name, or a description made up out of several names. In this way someone could know what the name 'tragelaphus' (or 'goatstag', which is the same) signifies: he could know that it signifies 'some kind of animal made up of goat and stag'. But it is impossible to know what the goatstag is, for nothing in reality is a goatstag.'4 A 'name' here - and throughout this context - is not a proper name, but a 'name for a nature', nomen naturae, what Frege would call a Begriffiwort, concept-word, or what Geach would call a predicable expression. There are obvious similarities here with Frege's own doctrine, that concept-words have reference. It should be noticed that though St Thomas uses the word 'name' here, as Frege does not, the nature which is so 'named' is not considered to be in Fregean terms an object. A nature is not something complete, selbstiindig, any more than Frege's Begriffe are. St Thomas would say it is 'more something that belongs to an existent 5 than an existent itself. It is, however, something real, something actual, something in the realm of ens. The question of the genuine existence of non-actual or non-real entities, such as numbers, which was so important to the mathematician Frege, is of little interest to St Thomas. Given that for St Thomas the field of interest is the real or actual, there is an even closer parallel between what St Thomas says and Kripke's doctrine on the reference of natural-kind terms. But there is an important difference here, too: Kripke is discussing the naming of natural kinds that we are acquainted with, while St Thomas is more interested in the question of how we can come to know or prove that a nomen naturae which we come across in fact refers to any nature. A nature is 'what a thing is': it is expressed by the definition of the thing. 6 The point being made here is that on the one hand one cannot know what a thing is until one has found and investigated it, while on the other one has to have some notion of it if the search for it - the answering

The Signification of a Na me

39

of the question an est? - is even to begin. This notion is supplied by what the word means, the significatio nominis. Borrowing slightly later jargon, we might say that we cannot have a real definition of a thing until we have found it, and thus know that it exists; but the search for it has to start from a nominal definition. This is made clear a little later on. On the first point, he supposes first that a definition is a description which signifies what a thing is. But if there could be no description of a thing other than its definition, it would be impossible for us to know that a thing exists without knowing what it is. This is because it is impossible for us to know that something exists except by means of some description of that thing. For we cannot know whether a thing that we are completely ignorant of exists or not. But there is such a thing as a description of a thing, apart from its definition. This is either a description which explains what the name signifies, or a description of the thing itself which has the name, which is different from the definition, in that it does not signify what the thing itself is, as the definition does, but perhaps some accident of it.7 It seems possible to neglect the 'other descriptions' referred to here: St Thomas himself seems to do so, and even makes some theoretical diffi­ culty about whether they can be really useful.8 In any case, what does not exist will not have any accidents, any more than it has a nature or quiddity: so when we start from a position of complete ignorance about whether a thing exists only the significatio nominis will be available to us. When St Thomas really sets himself to prove the existence of some­ thing, there is no doubt that the description of the thing he uses is the significatio nominis. His first criticism of what he takes to be St Anselm's ontological argument,9 is that perhaps a person who hears the name 'God' may not understand that it signifies 'something greater than which noth­ ing can be thought of . 1 0 His own Five Ways, on the other hand, are clearly intended to prove the existence of a God, by proving the existence of something which falls under a description which (he claims) anyone would recognise as expressing the signification of the word 'God'. Each of the Ways ends with a tag to the effect that everyone understands that an object which answers to the description of a first cause, etc., is understood by everyone to be God, or. is called God by everyone, or is said to be God by everyone. 1 1 The point is made particularly clearly a little after his discus­ sion of the Anselmian argument: The answer to the second objection is that when a cause is being proved by means of its effect, we have to use the effect in the place of the definition of the cause, in order to prove that the cause exists.

40

God and Explanations This is particularly the case with God, since in order to prove that something exists, we have to take as the middle term [sc. in the 12 demonstration ) what its name signifies, not what it is. This is because the question 'what is it?' follows on from the question 'does 13 it exist?'

But immediately after this we have a complication within the notion of 'what a name signifies'. But the names of God are imposed in virtue of His effects, as will be shown later. Hence when we are proving that God exists by means of His effect, we can take as the middle term what this name 'God' s1gm · "fi1es. 1 4 This is the first appearance in the Summa of a distinction which plays an important role in the discussion of the names of God in I, q. 1 3. The distinction is between 'id a quo imponitur nomen ad significandum' and 'illud quad nomen imponitur ad significandum' (or equivalent phrases) ­ between that in virtue of which a name is imposed, and that which a name is imposed to signify. A good account of this distinction is given early on in the question. The answer to the second objection is that there is sometimes a difference, within what a name signifies, between that in virtue of which a name is imposed, and that which a name is imposed to signify. The name 'lapis', stone, for example, is imposed in virtue of its hurting the foot, 'laedit pedem'. But it is not imposed to signify what 'hurting the foot' signifies, but to signify some kind of body. If it were not so, then anything which hurts the foot would be a 15 stone. The inaccuracy of the etymology (which I believe derives from Isidore of Seville) is not relevant here. What is relevant is that we have a clear parallel here with Kripke's thesis about the difference between the fixing of reference and reference itself. The reference of the word 'helium', to use 16 Geach's illuminating example - which incidentally antedates Naming and Necessity by some time - was fixed in terms of the production of such-and-such lines in the solar spectrum: but the word refers not to a process of production but to an element. A later passage makes the parallel clearer. We have to say that that in virtue of which a name is imposed is not always the same as that which a name is imposed to signify. For just as we come to know a thing from its properties or operations, so we

The Signification of a Name

41

sometimes name the substance of a thing in virtue of some property or operation that it has. So, for example, we name the substance stone in virtue of some action that it has, i.e. its hurting the foot. But this name is not imposed to signify this action, but to signify the sub­ stance stone. 17 This point has already been made, and is familiar to us. Less familiar is a point that follows immediately: But if there are things which are known to us in themselves, such as heat, cold, whiteness, and the like, these are not named in virtue of something else. Hence in such things there is no difference between 8 what a name signifies and that in virtue of which a name is imposed. 1 There may be an attempt here to make something of the same point which Kripke wishes to make for the reference of the word 'pain' later in Na ming and Necessity. Be that as it may, what is of interest to us in this passage, given that we are trying to tease out St Thomas's doctrine about signifi­ cation and its relation to the answering of questions of existence, is that here we catch sight of a three-way distinction, as opposed to the two-way distinction we have seen so far. This is not a one-off slip of the pen: other passages seem to suggest that the three-way distinction appears to be 9 genuinely part of St Thomas's doctrine on signification as a whole. 1 The three-way distinction is as follows. First we have that in virtue of which a name is imposed, then that which a name is imposed to signify, then that which a name does signify. The first complication is that this last notion appears at first sight to be the very notion, that of the signification of a name, within which the distinctions are being made. But this does not of itself argue against St Thomas's claim to be making distinctions within the notion of what a name signifies: he is merely using one and the same expression both in a more generic and in a more specific use. The two uses seem to relate to a sort of a sense-reference distinction: we might say, crudely, that within 'what a word signifies' we can distinguish two other elements beside what the word actually in the end turns out to signify. The verbal complication is easily resolved, and in St Thomas's writing it does not seem to cause any confusion. Perhaps more perplexing is the fact that if we do introduce the notion of 'what a name signifies', in this more specific use, as in the last passage cited, the notion of 'that which a name is imposed to signify' seems to have no recognisable role. We could compare and contrast Kripke, for example: he distinguishes between the fixing of the reference and the reference, which clearly correspond to 'illud a quo imponitur nomen' and 'id quod significat nomen' in this use. Where does the notion of 'that which a name

42

God and Explanations

is imposed to signify' fit in? One might suspect mere confusion. St Thomas in fact sometimes even starts out by making the distinction between 'a quo imponitur nomen' and 'illud ad quod significandum imponitur nomen', but continues by contrasting it with 'illud quod nomen , 20 , ' s1gm fi1cat . On this point, McCabe suggests that when St Thomas distinguishes between 'id a quo nomen imponitur' and 'id ad quod significandum nomen imponitur', he is not simply pointing to the obvious fact that etymology is a poor guide to meaning. He is comparing the very odd difference between knowing how to use a word and knowing what it means when used of God to the difference between the etymology of a word and its , 21 meamng . This at first sight is not of much use for our problem: it tells us nothing about the difference between 'id ad quod significandum nomen imponi­ tur' and 'id quod significat nomen'. What is more, this account lacks the generality which I claimed that this doctrine had: on this account, this is a problem which arises with language about God alone, while I am trying to see here a doctrine of general application. Fortunately there are two texts, which, while related to what McCabe says, bring out all three of the different notions: We must say something else, then: that names of this kind [e.g. 22 'good', 'wise', etc.] signify the divine substance. The answer to the third objection is that these names, 'good', 'wise', and the like, are indeed imposed in virtue of perfections which proceed from God to creatures; but they are not imposed to signify the divine nature, but to signify those very perfections in them­ selves.23 We see here that when such words as 'good' and 'wise' are used of God, what they in fact signify is God's own nature: but that is not what they are imposed to signify, and a fortiori not what they are imposed in virtue of. This, indeed, goes to make McCabe's point. But what McCabe has not noticed is that the point can be generalised. Though St Thomas may have come to make the distinction in order to sort out the theological problem McCabe refers to, it is of wider philosophical interest than that. The theological point being made here is that a name that is imposed to signify a perfection which is usually distinct from the nature of the being which has that perfection, may, when applied to God, signify God's own simple nature. Q!.iite generally, on the other hand, a name which is

The Signification of a Name

43

imposed to signify a certain nature may fail to do so, as the examples we first examined from the Commentary on the Posterior Analytics make clear. The name 'goatstag', though imposed to signify a certain nature, certainly does fail to signify any such nature, as we have seen: and, according to the opinion of for example the Biblical Fool, the name 'God' may so fail as well. 24 St Thomas thus has two notions which he opposes to 'id a quo imponitur nomen': that of 'id quod nomen imponitur ad significandum' and that of 'id quod nomen significat'. It is true that for the most part these double each other uselessly - usually a name is imposed to signify a nature or a perfection, and does so. Most of what we set out to say we succeed in saying, most of what we set out to talk about we succeed in talking about. Hence in most cases it is all one which notion we oppose to the notion of 'id a quo imponitur nomen' - we can start with one and continue with the other. We have seen that in fact Aquinas does this on occasion, without thereby leading the reader into any serious confusion. But sometimes it is not all one: sometimes we need to allow for the possibility of a nomen naturae failing to signify the nature it is imposed to signify, as when we are asking whether there is anything of that nature, or, of course, when we are discussing the application of that word to God. We seem to have here a parallel to Frege's doctrines on proper names - that they can fail to refer. But there is an important difference here, too. Frege does not hold that a concept-word can fail to refer; indeed, he would be very unhappy with the suggestion that such a word can fail to refer merely because there is nothing that falls under the concept. That there is something which falls under a concept is not a mark of a concept - it cannot affect what the concept, the reference of the concept-word, is. 25 'Goatstag' would be a concept-word for Frege, and would thus refer to a concept, even though we cannot truly predicate 'being a goatstag' of anything. So, even though if anything is a goatstag it is an animal of a certain nature, and even though there is no animal of that nature, the word 'goatstag' does not, for Frege, cease to have reference. St Thomas, of course, does not have the Fregean notion of concept. He would say, as we have seen, that the word 'goatstag' is imposed to signify a certain nature, but since there is nothing of that nature there just is no such nature that it in fact signifies. But he does have some grasp of the Fregean point: he holds that names signify realities only mediately, by means of a ratio or conceptio: 'The description which a name signifies is the intellectual conception of the thing signified by the name . . . a name only signifies a reality by means of an intellectual conception'. 26 St Thomas would say, then, that in every case there is a ratio or description under which such a name signifies a nature, so that even if

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God and Explanations

there is no nature that is in fact signified, the word which is imposed to signify a nature still signifies a certain ratio. St Thomas, who is part of a philosophical tradition which ignores the modern problem of privacy, is naturally not bothered with the problem of how something mental, like the ratio, can be common to many thinking subjects. He would agree, moreover, with Frege that what a nomen naturae is true of makes no difference to what it signifies: The answer to the first objection is that there being many names is something that follows the signification of a name, not its predica­ tion. The name 'man', for example, is said in only one sense, no matter what it is said of, whether it be said truly or falsely. The name 'man' would have many senses only if we intended to signify differ­ ent things by it: if, for example, someone intended the name 'man' to signify what really is a man, and another meant to signify by the same name a stone or something else. Hence it is clear that a Catholic who says that the idol is not God is contradicting the heathen who says it is. This is because both are using the name 'God' to signify the true God. For when the heathen says that the idol is God, he is not using the word in the sense in which it signifies 'that which is thought to be God'. If he were, he would be speaking the truth, as even Catholics occasionally use this name with such a signification, as when they say 'All the gods of the heathen are demons'. 27 Apparently, then, the intended signification of a nomen naturae is not in the least affected by what it happens to be predicated of, whether that predication be made truly or falsely. But if this is so, then the intended signification of the name 'goatstag' is still some nature, the nature of some kind of animal composed of goat and stag. But the signification of that name cannot be a certain nature, as there is no such nature. At this point St Thomas seems to be badly in need ofthe Fregean notion of Begriff, concept, but he can still make shift with his own notion of ratio. We could say in Fregean terms that the reference of the name 'goatstag' is to a concept - this reference succeeds. It is intended to refer to a concept that is a nature, but it does not in fact so refer - this more specialised intended reference fails. We have a case here not of failure of reference, but of error of reference. The parallel is not to a proper name such as 'Don Quixote', which is intended to refer to a human being, and has a sense, but no reference; the parallel is rather to the use of proper names by the victims of deception. Tom Castro, the Tichborne claimant, who had spent some time in Australia and in Chile, was called 'Orton' by his opponents and 'Tichborne' by his supporters. 'Orton' was certainly the name of a

The Signification of a Name

45

criminal Australian butcher, and 'Tichborne' was certainly the name of an English aristocrat who had visited Chile. If the claimant was genuine, then the use of the name 'Orton' was mistaken in the following way: it was intended to refer to a human being, a human being who had spent time in Australia, and it did so refer; but it was also meant to refer to a criminal butcher, and it failed to refer to any criminal butcher. If the opponents of the claimant were right, then the name 'Tichborne' was mistaken in the following way: it was intended to refer to a human being, a human being who had spent time in Chile, and it did so refer; but it was also meant to refer to an English aristocrat, and it failed to refer to any English aristocrat. Likewise, 'goatstag' is intended to refer to a certain concept, and does so refer. But 'goatstag' is also intended to refer to a certain nature, and it fails to refer to any nature. Since there are no goatstags to possess that nature, there is no such nature either. St Thomas would have to say: 'goatstag' is intended to signify a certain ratio, and does so signify. But it is also intended to signify a certain nature, which it does not signify- since there are no goatstags to possess that nature, there is no such nature. The notion of 'illud ad quod significandum imponitur nomen', then, is used by St Thomas to double for 'id quod significat nomen' in making the distinction with 'illud a quo imponitur nomen' in order that the distinction can be used in cases where the name does not or may not signify any nature. This doubling or intentionalising of the notion makes this distinction a refinement on Kripke's distinction between the reference of a natural-kind term and that by which the reference is fixed. We have seen how the notion of a name's being imposed to signify a nature relates to Fregean notions of reference, and takes account of the problems which arise when we do not know whether there is anything that has the nature signified. What then of the other half of the distinction, the notion of 'illud a quo imponitur nomen'? Apart from its value to make the Kripkean point about fixing of reference, is it, like the other notion, of any interest in itself? McCabe related this notion to its theological use, but the discussion of questions of existence, with which we are principally concerned, may seem to suggest that there is more to be made of it. We noticed that it was difficult to make sense of the idea of having any ratio (other than the significatio nominis) of the kind of thing whose existence we are proving; we also noticed that St Thomas actually does use the significatio of the name 'God' when proving His existence, and seems to suggest that this is what we should do to prove the existence of the goatstag. But what is this significatio nominis here? It cannot be the significatio nominis in the re­ stricted sense, 'id quod nomen significat': whether the name actually signifies a real nature is just the point at issue when we are asking whether

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God and Explanations

anything of that kind actually exists. The notion of 'id ad quod significan­ dum imponitur nomen' looks more useful: we are certainly going to need to know what the name is imposed to signify. We are going to need to 28 know that it is imposed to signify a nature rather than an individual: and presumably part of knowing what the name is imposed to signify may be knowing that it is imposed to signify a nature rather than a (possibly 29 accidental) perfection, or relation. But beyond that, what notion can we have of something about whose existence we are not sure? We certainly need to have some notion of it, to have some description or ratio: if not, as we have seen, the search could never start. As St Thomas says: 'If there were someone who had no knowledge of God under any description whatsoever, he would not even name Him, except perhaps as we utter words whose meaning we are ignorant of?'. 3 0 In fact, St Thomas gives considerable importance in this context to the notion of 'a quo imponitur nomen ad significandum', as giving us the ratio or rationes we need when we are seeking to prove something's existence. For example, as we have already seen, 3 1 St Thomas considers that the fact that 'nomina Dei imponuntur ab effectibus', God's names are imposed in virtue of His effects, is relevant to establishing 'quid significet hoc nomen Deus', what the name 'God' signifies, with a view to proving that God exists. The same is true of the goatstag passage: the ratio of 'goatstag' that we could use when proving that the goatstag exists or not is one that is 'ex pluribus nominibus compositam', made up out of several names, and it is this that tells us that the name 'goatstag' signifies 'some animal made up out of goat and stag'. This is another case where the significatio nominis is told us by 'a quo imponitur nomen'. St Thomas elsewhere explains the relation between 'a quo imponitur nomen' and the significatio nominis. For example, we have already learnt 32 from passages cited above that the different names of God are imposed from His effects. This remark is refined when we discover that these different names are not synonymous because 'though they signify one thing, they signify it under various different rationes or descriptions'. 33 Different names, that is, have different descriptions under which they signify, and the different names answer to the different effects in virtue of which they are imposed. Hence the ratio or description under which a name signifies, which may be all that we know when we begin to enquire whether that which it signifies exists or not, is known by us from our knowledge of that in virtue of which it is imposed to signify. There is one last text, which helps to bring all these considerations together:

47

The Signification of a Name

So because God is not known to us in His own nature, but is glimpsed by us in virtue of His operations or effects, we can name Him from these, as has been said above. Hence this name 'God' is the name of an operation, in so far as that in virtue of which the name is imposed is concerned, since this name is imposed in virtue of His universal providential care for the world. For everyone who speaks of God understands that 'God' names that which has universal 3 providential care for the world. 4 This passage clearly seems to relate to the tags with which each of the Viae concludes, which I referred to above. Those tags are to be thought of as filling out what the name 'God' signifies, and here St Thomas relates those generally accepted notions of what 'God' signifies to that in virtue of which the name is imposed. We may find his unquestioning use of etymology, and especially of lsidorean etymologies, to help him establish that in virtue of which a name is imposed, and thus what it signifies, rather over-trusting. But this trait does not detract from the value of the account as a whole. It should be of general value to Kripkeans and other essential­ ists when they move on from referring to easily recognisable natural kinds and come to wonder about the problems involved when we are trying to establish the existence of a natural kind or of an individual of such a kind. In any case, it should be clear that when St Thomas asks 'Does God exist?' his question is backed up by a fairly solid account of how we can understand such a word as 'God' in such a question. It remains to be seen whether he also has an equally full account of how we can understand the word 'exists'. NOTES I . Summa Theologiae, I, q. 1 3 . 2. Summa Theologiae, I , q. 2 , a. 2 . 3 . Commentary o n the Posterior Analytics, L.I, lect. 2, n. 1 7 : Antequam sciatur d e aliquo a n sit, non potest sciri proprie d e e o quid est: non entium enim non sunt definitiones. Unde quaestio, an est, praecedit quaestionem, quid est. Sed non potest ostendi de aliquo an sit, nisi prius intelligatur quid significatur per nomen. 4. Commentary on the Posterior Analytics, L.11, lect. 6, n. 461 : Qµia enim non entis non est aliqua quidditas vel essentia, de eo quod non est nullus potest scire quod quid est; sed potest scire significationem nominis, vel rationem ex pluribus nominibus compositam: sicut potest aliquis scire quid significat hoc nomen tragelaphus, vel hircocervus, quod idem est, quia significat quoddam animal compositum ex hirco et cervo; sed impossibile est scire quod quid est hircocervi, quia nihil est tale in rerum natura. 5. 'Magis entis quam ens': Summa Theologiae, I, q. 45, a. 4; see P. T. Geach, 'Form and existence', in God and the Soul (London: Routledge and Kegan Paul, 1969) For a discussion of the notion of 'real existence', see Chapter 5 below, pp. 56, 66-7. 6. Commentary on the Posterior Analytics, L.2, lect. 8, n. 484: '[D]efinitio [est] ratio significativa ipsius quod quid est.' 7. Commentary on the Posterior Analytics, L.2, lect. 8, n. 484:

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God and Explanations Circa primum, supponit primo quod definitio sit ratio significativa ipsius quod quid est. Si autem non posset haberi aliqua alia ratio rei quam definitio, impossibile esset quod sciremus aliquam rem esse, quin sciremus de ea quid est; quia impossibile est quod sciamus rem aliquam esse nisi per aliquam illius rei rationem. De eo enim quod est nobis penitus ignotum, non possumus scire si est aut non. Invenitur autem aliqua ratio rei praeter definitionem; quae quidem vel est ratio expositiva significationis nominis, vel est ratio ipsius rei nominatae, altera tamen a definitione, quia non significat quid est, sicut definitio, sed forte aliquod accidens.

8. As we shall see later, when the question of the existence of God comes up, St Thomas uses the significatio of the name 'Deus', not some other description of God. The same is true of the goatstag mentioned above. On the theoretical difficulty, see Commentary on the Posterior Analytics, L. II, lect. 7, nn. 474-6. 9. St Thomas, like Gaunilo, clearly understands this famous argument of St Anselm in a way which assimilates it to a great extent to Descartes' ontological argument. It is a matter of dispute whether this reading is faithful to the subtleties of St Anselm's thought. IO. Summa Theo/ogiae, I, q. 2, a. 1, ad 1 : 'forte ille qui audit hoc nomen Deus non intelligit significari aliquid quo maius cogitari non possit'. 1 1 . Summa Theologiae, I, q. 2, a. 3, c. 1 2 . St Thomas holds, in the Commentary on the Posterior Analytics, L. II, lect. 1, n. 412, that to ask 'is there such a thing?' is to ask 'is there a middle term which can be used in a demonstration of its existence?' 1 3 . Summa Theologiae, I, q. 2, a. 2, ad 2: Ad secundum dicendum quod, cum demonstratur causa per effectum, necesse est uti effectu loco definitionis causae ad probandum causa esse: et hoc maxime contingit in Deo, quia ad probandum aliquid esse, necesse est accipere pro medio, quid significet nomen, non autem quod quid est, quia quaestio quid est sequitur ad quaestionem an est. 14. Summa Theologiae, I, q. 2, a. 2, ad 2: 'Nomina autem Dei imponuntur ab effectibus, ut postea ostendetur: unde demonstrando Deum esse per effectum, accipere possumus pro medio, quid significet hoc nomen Deus'. 15. Summa Theologiae, I, q. 13, a. 2, ad 2: Ad secundum dicendum quod in si gnificatione nominis aliud est quandoque a quo imponitur nomen ad significandum et aliud ad quod significandum nomen imponitur; sicut hoc nomen, lapis, imponitur ab eo quod laedit pedem, non tamen imponitur ad hoc significandum quod si gnificet laedens pedem, sed ad significandam quamdam speciem corporum, alioquin omne laedens pedem esset lapis. A parallel is to be found at De Potentia, q. 9, a. 3, ad I . 16. P . T . Geach, essay 'Aquinas', in Three Philosophers (Oxford: Blackwell, 1961), p . I 09ff. 17. Summa Theologiae, I, q. 1 3 , a. 8c. Dicendum quod non est semper idem id a quo imponitur nomen ad significandum, et id ad quod significandum nomen imponitur. Sicut enim substantiam rei ex proprietatibus vel operationibus eius cognoscimus, ita substantiam rei denominamus quandoque ab aliqua eius operatione vel proprietate; sicut substantiam lapidis denominamus ab aliqua actione eius quia laedit pedem; non tamen hoc nomen impositum est ad significandum hanc actionem, sed substantiam lapidis. 1 8 . Summa Theologiae, I, q. 13, a. 8c: 'Si qua vero sunt quae secundum se sunt nota nobis, ut calor, frigus, albedo, et huiusmodi, non ab aliis denominantur. Unde in talibus idem est quod nomen significat, et id a quo imponitur nomen ad significandum.' 19. See, for example, Summa Theologiae, I, q. 13, a. 7, ad I . 20. For example, in Summa Theologiae, I , q . 1 3 , a . 8 c and a d 2. 2 1 . In his translation of Summa Theologiae, I, qq. 1 2-13, Blackfriars edn, vol. 3, Appendix 3, p. 105. 22. Summa Theologiae, I, q. 13, a. 2c: 'Et ideo aliter dicendum est quod huiusmodi quidem nomina [sc. bonus, sapiens et huiusmodi] significant substantiam divinam.' 23. Summa Theologiae, I, q. 13, a. 9, ad 3 : A d tertium dicendum quod haec nomina, bonu, sapiens, e t similia, imposita quidem sunt a perfectionibus procedentibus a Deo in creaturas. Non tamen sunt imposita ad significandum divinam naturam, sed ad significandum ipsas perfectiones absolute.

The Signification of a Name

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24. 'The fool has said in his heart, there is no God', Psalms, 14 [ 1 3]: I , and 53 [52]: I . 25. G . Frege, Grundlagen der Arithmetik (Oxford: Blackwell, 1959), §§ 46, 5 1 , 52. 26. Summa Theologiae, I, q. 13, a. Sc and ad I: 'Ratio enim quam significat nomen est conceptio intellectus de re significata per nomen . . . . nomen non significat rem nisi mediante conceptione intellectus'. 27. Summa Theologiae, I, q. 13, a. 1 0, ad I : Ad primum dicendum quod nominum multiplicitas non attenditur secundum nominis prae­ dicationem, sed secundum significationem. Hoc enim nomen, homo, de quocumque prae­ dicetur, sive vere sive false, dicitur uno modo. Sed tune multipliciter diceretur si per hoc nomen, homo, intenderemus significare diversa; puta, si unus intenderet significare per hoc nomen, homo, id quod vere est homo, et alius intenderet significare eodem nomine lapidem vel aliquid aliud. Unde patet quod catholicus dicens idolum non esse Deum, contradicit pagano hoc asserenti; quia uterque utitur hoc nomine, Deus, ad significandum verum Deum. Cum enim paganus