Perception As A Capacity For Knowledge 0874621798

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THE AQUINAS LECTURE, 2011

PERCEPTION AS A CAPACITY FOR KNOWLEDGE

JOHN MCDOWELL

MARQUETTE UNIVERSITY

PRESS

© 2011 Marquette University Press Milwaukee, Wisconsin 53201-3141 All rights reserved. www.marquette.edu/mupress/

T

he Wisconsin-Alpha Chapter of Phi Sigma Tau, the International Honor Society for Philosophy at Marquette University, each year invites a scholar to deliver a lecture in honor of St. Thomas Aquinas. The 2011 Aquinas Lecture, Perception as a Capacity for Knowledge, was delivered on Sunday, February 27, 2011, by John McDowell. Prof McDowell is a Distinguished University Professor of Philosophy at the University of Pittsburgh.

Under the auspices of the Wisconsin-Alpha Chapter of Phi Sigma Tau LIBRARY OF CONGRESS CATALOGING-IN-PUBLICATION DATA

McDowell, John Henry. Perception as a capacity for knowledge / by John McDowell. p. cm. - (Aquinas lecture; no. 75) Includes bibliographical references. ISBN-13: 978-0-87462-179-2 (hardcover: alk. paper) ISBN-I0: 0-87462-179-8 (hardcover: alk. paper) 1. Perception (Philosophy) 2. Knowledge, Theory of I. Title. B828.45.M43 2011 121:34-dc22 2010051475 Printed in the United States of America. @The paper used in this publication meers the minimum requirements of the American National Standard for Information SciencesPermanence of Paper for Primed Library Marerials. ANSI Z39.48-1992. ~

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discounting the possibility that one's perceptual warrant is defeated in the present circumstances. And Burge insists-plausibly enough-that we should not credit ordinary adult human beings, who may be only minimally articulate and reflective, with the ability to deploy conceptual equipment of that level of sophistication. Thus he goes on: [S]uch a claim [he is still considering a claim like I saw such and such] does not indicate the epistemic role of being in a perceptual state in undergirding the perceptual belief. Understanding the warranting force of being in a relevant-seeming perceptual state and having some grip on the general shape of conditions that undermine such force are part of having a reason [as opposed to just being entitled]. The idea that all human adults with warranted perceptual beliefs have even a conceptualized"know-how" mastery of this territory would, I think, overestimate the conceptual capacities of adult human-kindY

Burge's thought is this: if a subject brings the warrant a perceptual state gives her for believing something about how things are in her environment within the scope of her self-consciousness, she becomes aware that she has something like evidence, in itself inconclusive, for the truth of the belief That is why he thinks that if someone invokes a perceptual state in offering a justi6cation that is supposedly strong enough for her to claim knowl13 Ibid.

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edge, she needs to be able to situate her mention of the perceptual state in an argumentative context involving conceptual apparatus that can be understood only by someone with a high degree of conceptual sophistication. And that is why he thinks that if, with Sellars, we endorse internalism about the warrant for all cases of perceptual knowledge as enjoyed by rational subjects, we commit ourselves to an excessively intellectualistic ~onception of such perceptual knowledge. 7. Everything turns here on the assumption that the warrant a perceptual state provides for a belief cannot guarantee the truth of the belief The Sellarsian idea I am considering is that there is a kind of perceptual knowledge that is special to rational subjects, perceptual knowledge whose instances are positions in the space of reasons. Burge does not see that this idea brings into question his assumption that perceptual states as such can provide only inconclusive warrant for beliefs. His accusation of excessive intellectualism, as I have reconstructed it, depends on supposing that everyone, including Sellars, would accept that the warrant provided by a perceptual state cannot be conclusive. But the Sellarsian idea makes room for a conception of perceptual states on these lines: when *all goes well in the operation of a perceptual capacity of a sort that belongs to its possessor's rationality, " 1-1, ;.(

!.

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a perceiver enjoys a perceptual state in which some feature of her environment is there for her, perceptually present to her rationally self-conscious awareness. This presence is an actualization of a capacity that belongs to the subject's reason. Reason is at work, that is, in the perceptual presence to rational subjects of features of their environment. And if a perceptual state can consist in a subject's having a feature of her environment perceptually present to her, that gives the lie to the assumption that a perceptual state cannot warrant a belief in a way that guarantees its truth. If a perceptual state makes a feature of the environment present to a perceiver's rationally self-conscious awareness, there is no possibility, compatibly with someone's being in that state, that things are not as the state would warrant her in believing that they are, in a belief that would simply register the presence of that feature of the environment. The warrant for belief that the state provides is indefeasible; it cannot be undermined. This conception of the kind of perceptual state a perceiver is in 'When all goes we!! in the exercise of a rational perceptual capacity fits what I think is a perfectly intuitive understanding of the idea of, for instance, seeing something to be so. When one sees something to be so, one is in a perceptual state in which its being so is visually there for one, so that one has a conclusive warrant for a corresponding belief This stands in contrast with the conception of

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seeing that 6gures in Burges accusation of excessive intellectualism: on Burge's assumptions, claiming to see such and such can only be invoking a perceptual state that inconclusively warrants a corresponding belief, while standing ready to argue that on this occasion the warrant is good enough for the belief to count as knowledgeable. This different understanding of what it is for perceptual states to be experiences of, for instance, seeing clearly undermines Burges argument, as I have reconstructed it, that internalizing the warrant for beliefs provided by perceptual states would require a level of conceptual sophistication that is implausible for ordinary adult human beings. One can conceive oneself as, for instance, having knowledge rationally grounded in an exercise of a capacity to enjoy perceptual states in which features of the environment are perceptually there for one, without needing a level of sophistication beyond what might be possessed by someone who was only minimally articulate and reflective. There is no excessive intellectualism in a conception of a capacity in whose exercise a subject acquires knowledge that is grounded, and known by her to be grounded, in the perceptual presence to her of objective states of affairs. An ordinary adult human being might not put it in those terms, but that is what she would mean if she said something like "I can tell a green thing when I see one: It does

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not require much sophistication to be able to claim such capacities. Note that on this picture it is a perceptual state itself that warrants one in a belief that counts as knowledgeable by virtue of having such warrant. That is so even when the warrant is a justi6cation in Burge's sense, not just an entitlement. When one knows something to be so by virtue of seeing it to be so, ones warrant for believing it to be so is that one sees it to be so-not ones believing that one sees it to be so, which would raise the question what warrants one in that belief, the question Burge exploits in order to argue that the Sellarsian picture falls into an excessive intellectualism. When an exercise of a rational perceptual capacity puts a subject in a perceptual state that is her seeing something to be so, the perceptual state that is her seeing it to be so comes within the scope of her self-consciousness, so the warrant it provides, as the perceptual state it is, is ajusti6cation in Burge's sense: warrant that is accessible to the warranted individual, as Burge puts it. But even though the warrant is a justi6cation, not just an entitlement, what warrants the subject in her belief about the environment is the perceptual state, not, as Burge thinks, a belief about the perceptual state. 14 Of 14 See "Perceptual Entitlement'; 529, where Burge insists that the reason that is the warrant when one invokes a perceptual state in offering a justification for

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course one believes what one says when one cites a perceptual state in offering a justification, but it would be a confusion to infer that the warrant one claims to have is constituted by the belief as opposed to the perceptual state. 8. What I am suggesting is this: the difference it makes if we focus on a kind of perceptual knowledge that is rationality at work is not, as Burge thinks, that we can consider rational subjects, at least some of them, as able to embed self-ascriptions of perceptual states that provide inconclusive warrant for beliefs in sophisticated justifications for the beliefs. The difference is rather that rational subjects can be, and can know themselves to be, in perceptual states that make features of the environment present to them, and so provide conclusive warrant for corresponding beliefs. Burge does not so much as contemplate a conception of perceptual states on those lines. Why not~ Burge's accusation of excessive intellectualism turns on the assumption that perceptual states, in themselves, can provide only defeasible warrant for beliefs. What persuades him of that~ I think the answer is that he thinks that it follows from, perhaps even that it merely restates, the undeni-

a belief is a belief about the perceptual state, not the perceptual state itself.

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able fact that any perceptual capacity is fallible. He writes: Because of every individual's perceptual limitations, and because of the nature of empirical warrant, every perceptual state, including those that contribute to warrant (and likewise every perceptual belie£ including warranted ones) could in principle have been in circumstances in which it was prone to error. No perceptual state type can be reliably veridical under all conditions. Perceptual states are components of perceptual competencies. Our perceptual competencies are fallible. All perceptual states (type or token) and all perceptual competencies are subject to possible error. IS The last sentence of that passage implies that in no case in which a subject is in a given perceptual state does the state warrant a belief in a way that excludes the possibility of falsehood. 16 Burge makes that view of perceptual warrant explicit when he says this: It is a fundamental feature of perceptual warrant, hence perceptual entitlement [as we know, he thinks perceptual warrant can only be entitlement j, that it allows that an individual can be fooled while retaining warrant. 17 15 "Perceptual Entitlement'; 535. 16 I think this captures what Burge means by talking of token states. 17 "Perceptual Entitlement'; 536.

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Having a perceptual warrant, according to this passage, is compatible with being fooled-compatible with being wrong in the warranted belief. Perceptual warrant is in itself neutral as to whether a belief it warrants is true or not. It would follow that even in a case in which one is not fooled, the warrant provided by ones perceptual state leaves open, in itself, a possibility that one is fooled. That is why Burge thinks that in justifying a perceptual belief, one would need to place an invocation of the warrant provided by a perceptual state in the context of a sophisticated argument, directed at showing that one is warranted in discounting that possibility. 9. I think this reflects a mistake about the concept of fallibility. And I do not believe the mistake is special to Burge. On the contrary, it is pervasive in epistemology. It is typical for discussions of the epistemology of perceptual knowledge to begin with the assumption I have found in Burge, that experience itself cannot provide better than inconclusive warrant for belief. Often this is quickly taken for granted. But if a ground is offered, it is typically something on the lines of Burges appeal to the fallibility of all our perceptual capacities. Burge thinks a Sellarsian epistemology for perceptual knowledge as enjoyed by rational subjects falls into an unacceptable intellectualism. I have

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suggested this reflects a blind spot for a conception of perceptual warrant that Sellars enables us to frame. And I think the way Burge exploits considerations about fallibility, to underwrite the view about perceptual warrant that is essential to his accusation against Sellars, is exemplary of a widespread tendency in philosophical thinking about perception as a capacity for knowledge. It should be instructive to think this through. Fallibility is a property of capacities, or perhaps of cognitive subjects as possessors of capacities. If a capacity is fallible, or if, to speak in that other way, anyone who has it is fallible in respect of it, that means that there can be exercises of the capacity in which its possessor does not do what the capacity is specified as a capacity to do. That account of fallibility is completely abstract. It puts no restrictions on what a fallible capacity can be a capacity to do. Certainly Burge is right that all our perceptual capacities are fallible. But we can acknowledge that a capacity is fallible without precluding ourselves from saying that what it is a capacity to do is this: to get into states that consist in having a certain feature of the objective environment perceptually present to one's selfconsciously rational awareness. If that is what a capacity is a capacity to do, that is what one does in a non-defective exercise"of it. And I have urged that if a perceptual state can be described in those

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terms, there is no possibility, compatibly with a subject's being in such a state, that things are not as she would believe them to be in the beliefs that the state would warrant. When we acknowledge that a capacity is fallible, we acknowledge that there can be exercises of it that are defective, in that they fail to be cases of what the capacity is specified as a capacity to do. That does not preclude us from holding that in non-defective exercises""of a perceptual capacity subjects perceptual states that provide indefeasible warrant for perceptual beliefs. For instance, a capacity to tell whether things in one's field of vision are green is a capacity -fallible, by all means-to get into positions in which the greenness of things is visibly there for one, present to one's rationally self-conscious awareness. If something's greenness is visibly there for one, one has conclusive warrant for believing that it is green. One's perceptual state leaves no possibility that it is not green. That the capacity is fallible means that a possessor of it can be fooled, as Burge puts it; for instance, if the light is unsuitable for telling the colours of things, one can take something's greenness to be visually present to one when the thing is not green at all. It is wrong to think it follows that even when one is not fooled in an exercise of this capacity, one's position must fall short of having something's greenness visibly present to one, and thereby having an indefeasible

"get "into'

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warrant for believing the thing to be green. That is just what one's position is in a non-defective*"exercise of the capacity. = "-=-..::'- - - If we follow the etymology of the word, fallibility is a possibility of being deceived. That is an imperfection in cognitive capacities. But the mistake I am pointing out may be easier to recognize if we consider its analogue in application to imperfection in other sorts of capacities. Think of the capacity to sink eight-foot putts. Even the best golfers do not sink all their eight-foot putts. The idea I am considering is that there cannot be capacities, acknowledged to be fallible, whose non-defective exercises put their possessors in positions in which they have conclusive warrant for beliefs. One might as well think there cannot be a capacity, of course not guaranteed success in every exercise, in whose non-defective exercises a possessor of it actually sinks eight-foot putts. 10. It might seem that this way of dealing with imperfection in capacities cannot have the kind of significance in epistemology that I am suggesting it does. To say that a perceptual capacity is fallible, or that anyone who has it is fallible in its exercise, is to say that the capacity does not ensure that its possessor is always in a position to discriminate defective exercises from non-defective exercises. If a capacity

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did ensure that, it would be in principle infallible; through carelessness or insufficient attention, someone might still mistake defective exercises for non -defective exercises, but the capacity itself would be perfect. But that sort of perfection is surely not within our reach. That is the point of saying, not just that we are not guaranteed to be correct in all our perceptual beliefs, but that our perceptual capacities themselves are fallible. It is not just that we are prone to carelessness and inattentiveness, but that no perceptual capacity excludes all possibility of defective exercises such that, however careful or attentive one was, one would not recognize them as defective, at least at the time. And now it is tempting to argue like this: even if we grant, perhaps temporarily and for the sake of argument, that a non-defective exercise of a perceptual capacity puts one in a state that consists in having some feature of one's environment present to one, being in such a state cannot have the epistemological significance I have been claiming for it; it cannot provide one with indefeasible warrant for a belief that registers the presence of that feature. Perhaps a perceptual state would give one indefeasible warrant for a suitably related belief if one knew that the current exercise of one's perceptual capacity was non-defective. But to accept, as we must, that the capacity is fallible is to accept that defective exercises of it can be indiscriminable, at least at the time, from

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non-defective exercises. And it can seem to follow that even if the current exercise is not defective, the subject cannot know that it is not defective. It can seem to follow that even on an occasion on which someone is in a perceptual state of the kind I am claiming we can describe in terms of the presence to her of a feature of her environment, her perceptual state is, jor all she knows, not of that kind-her current exercise of her perceptual capacity is,jor all she knows, defective. So surely she does not know whatever it is about the environment that she takes her perceptual state to enable her to know. In response to this, we need to emphasize the connection between reason and self-consciousness. A rational perceptual capacity is a capacity not only to know certain kinds of thing about the environment, but, on an occasion on which one knows something of the relevant kind through the exercise of the capacity in question, to know that that is how one knows it. The capacity-of course fallible-to know, on certain occasions, that one's experience is revealing to one that things are a certain way, which is a bit of self-knowledge, is just an aspect of the capacity-of course fallible-to know through experience, on those occasions, that things are that way. It is a single capacity, self-consciously possessed and exercised. A bit of rational perceptual knowledge includes knowledge that it is through perception that one knows whatever it

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is that one knows about the environment. And we need to avoid that bad inference from the fallibility of the capacity; not only in connection with its guise as a capacity for knowledge about one's environment, but also in connection with its guise as a capacity for self-knowledge. Granted, one can mistake a defective exercise of the capacity for a nondefective exercise. But it does not follow that the capacity cannot be correctly described as a capacity to know things about the environment. And it is just the same point, applied to the same capacity in a different guise, to say this: it does not follow that the capacity cannot be correctly described as a capacity to get into positions in which one knows that it is through ones perceptual state that one knows something about the environment-and so knows that ones perceptual state conclusively warrants one in the belief in question. Defective exercises of a perceptual capacity can be indiscriminable from non-defective exercises. It is a mistake to infer that even on an occasion on which the capacity is working perfectly, the current exercise of it is, for all one knows, defective. Here is Sebastian Rodl's excellent statement of the point: The argument [from illusion1is: Whenever I seem to know something [on the basis of perceptual experience J, I might have been fooled. Had I been fooled, I would not have known that I was. I would not have

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been able to tell my situation apart from one in which I am not fooled. This shows that my grounds do not place me in a position to exclude that I am in such a situation. They do not enable me to exclude that I am fooled.-The argument supposes that, had I been fooled, I would have believed the proposition in question on the same grounds on which I believe it now that I am not fooled. This straightforwardly entails that these grounds do not establish the truth of what I believe and therefore do not provide me with knowledge. But when I know something on the ground that, say, I perceive it to be the case, then I would not, had I been fooled, have believed it on this ground, for, had I been fooled, I would not have perceived it to be the case. Hence, when I am not fooled, my grounds exclude that I am fooled: when I perceive how things are, I am not fooled with regard to how they are. One might object that this grants me grounds that rule out error at the price of making it impossible for me to know whether my belief is based on such grounds. For, when I am fooled, I do not know that I am fooled. So I can never know whether I am not fooled and my beliefs are based on grounds that exclude their truth, or whether I am fooled and such grounds are unavailable to me. This objection repeats the mistake: from the fact that, when I am fooled, I do not know that I am, it does not follow that, when I am not fooled, I do not know that I am not. When I know that p as I perceive it to be the case, then I know that I perceive that p. Thus _!ru.? i~ ~positi~_~_to distinguish my situation from

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any possible situation in which I would be fooled, for, in any such situation, I would not perceive that p, while in the given situation I do. IS

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11. On the view I am recommending, a perceptual state in which some feature of the environment is present to one is an act of a rational capacity for knowledge, a capacity in whose exercises one knows things and knows how one knows them. It is important to keep that in mind. For different purposes, we might work with a different conception of what it would be for things to be present to subjects in their perceptual states, a conception that can be understood in abstraction from whether the perceptual states are acts of rational capacities for knowledge. But we should not think the view I am recommending can be tested by using that conception to interpret it. Let me explain. Consider, for instance, the capacity to know the colours of things by looking at them. Someone who is self-consciously in possession of such a capacity must know that the reliable capacity to get things right that she attributes to herself, when she says something like "I can tell a green thing when I see one'; is restricted to certain conditions of illumination. Her claim of authority for her ob-

servational reports of colour would be more fully expressed by saying "I can tell a green thing when I see one in a good light': She will not make statements about the colours of things for which she claims that authority if she knows, or has reason to believe, that the light is not suitable for exercising the capacity to know the colours of things by looking at them. 19 This brings into view an obvious dimension of the fallibility that attaches to any such capacity. The light can be unsuitable for knowing the colours of things by looking, without there being any clues to the fact. So someone can innocently take herself to be in a position to make observational claims about the colours of things when she is not. Now suppose someone who has learned to recognize colours in the usual way is enrolled in a psychological experiment. She is going to be asked to identify the colours of things she is shown in a succession of tests. There will never be any indication, visual or otherwise, that the light is unsuitable for exercising her capacity to recognize colours. But she is told that in half the tests the light will be unsuitable for colour recognition, though cunningly arranged so as not to seem suspicious in any way; in the other half the light will be a good light for

18 Self-Consciousness (Cambridge, Mass.: Harvard University Press, 2007), 157-8.

19 Sellars exploits this to explain what he calls "the logic of ,looks"; in part III of "Empiricism and the Philosophy of Mind':

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knowing the colours of things by looking at them. And now consider a test occasion on which the light is in fact the kind of light that would be, outside this context, a good light for knowing the colours of things by looking at them, and she is shown a thing that is in fact green. Intelligibly, given the way the light is, her perceptual state in looking at the thing is just like a perceptual state that, outside this context, she would rightly take to warrant her in saying that it is green. Should we conclude that the thing's greenness is visually present to her? If we did, the case would be a counterexample to the view I have been recommending. We would be supposing that a feature of the environment, the thing's colour, is visually present to her. But we cannot suppose she is in a position to know that things are the relevant way in the environment, in a bit of knowledge that includes knowing that it is her perceptual state that is providing her with that knowledge. In these circumstances, she is not in a position to know that things are the relevant waythat the thing is green-at all, let alone to know that it is by being in the perceptual state she is in that she knows that. For all she knows, this case is one of the cases in which the light is undetectably unsuitable for telling the colours of things by looking. 20 20 The case is a simple variant on one that Crispin Wright tries to exploit in "Comment on John McDowell's 'The Disjunctive Conception of Experience as

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It does not seem to matter whether what she is told about the experiment is true or not. Suppose the experimenters were lying. On all the test occasions, not just the one we are considering, the light is in fact the kind of light that would be suitable, outside this context, for knowing the colours of things by looking at them. But our subject has been told, apparently with authority, that on occasions to be determined by the experimenters the light will not be suitable for exercising that capacity of hers. It would be irrational for her to take herself to be in a position to know that the present occasion is not such an occasion. And that implies that she is not in a position to know that the thing is green, even though her visual state is related to the actual colour of the thing in just the way that, outside this context, would equip her to know that. But we should not conclude, in either of these cases, that the thing's greenness is visually present to her in the relevant sense. As I said, a perceptual state in which a feature of the environment is present to a subject, in the relevant sense, would have to be a non-defective exercise of a self-consciously possessed and exercised capacity to get into perceptual states that put the subject in a position Material for a Transcendental Argument"; in Adrian Haddock and Fiona Macpherson, eds., Disjunctivism: Perception, Action, Knowledge (Oxford: Oxford University Press, 2008), 390-404.

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to know, through perception, that things are the relevant way in the environment. And that is not how it is with the subject's perceptual state in the case we are considering. Considered in abstraction from the question whether a capacity to get to know things by looking is in play, her perceptual state is just like a perceptual state in which a feature of the environment is present to her. But it does not follow, nor is it true, that it is a perceptual state in which a feature of the environment is present to her in the sense that matters for the view I am recommending. Is this a cheat? Am I just defining away a difficulty IeS . that will persist in some different shape? It would be embarrassing if, on the assumptions I would need in order to set this case aside, it would turn out that no perceptual state could ever count as, say, making something's colour visually present to its subject. But there is no reason to accept that. In the case of the experimental subject, the experimental set-up confronts her with a specific possibility that the light is, on this occasion, unsuitable for knowing the colours of things by looking at them: a possibility about which we have to acknowledge that, in these circumstances, she does not know that it does not obtain. We have to acknowledge that for all she knows this is one of the occasions that she has been told there will be, on which the experimenters have seen to it that the light is undetectably unsuitable for the exercise of

\/ II'

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that capacity. But outside this kind of context-that is, where there is no s~Eific reason to suspect that the light is unsuitable-there is no corresponding acknowledgment that we have to make. The mere fact that it is possible for lighting conditions to be undetectably unsuitable for knowing the colours of things by looking at them is not a reason to say that for all she knows the present lighting conditions are unsuitable. That would just be a version of that mistaken view about what follows from the sheer fact of fallibility. We go wrong if we generalize from the case of the experimental subject to cases in which no specific possibility that would make knowledge unavailable is in the offing. The experimental subject has a specific reason to think the light may be unsuitable on this occasion, and the fact that she cannot rule out that possibility undermines her capacity to know the colours of things by looking, even on an occasion on which the light is in fact suitable for the capacity. In the general case, in contrast, the sheer fact that lighting conditions can be undetectably unsuitable does not present the subject with a possibility that she would need to rule out before she could claim to know the colours of things by looking. As always, we have to acknowledge that her capacity to know the colours of things by looking is fallible, among other reasons because it is vulnerable to undetectably unsuitable lighting conditions. So in making

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a claim that she takes to be authoritative by virtue of issuing from that capacity, she runs the risk that she will turn out not to have spoken truly, let alone knowledgeably, because the light was undetectably unsuitable. But again as always, the sheer fact of fallibility does not show that on an occasion when she makes such a claim and that risk does not materialize, she was not giving expression to knowledge, and knowledge that she knew she had. I suggested that it does not matter, for the the case of the experimental subject, whether what she is told about the experiment is true, so long as she has reason to believe it. Does it even matter that what she is told, truthfully or not, is that the light will be unsuitable for telling colours half the time, as in the case I described? Suppose the experimenters tell her they are going to determine whether the light will be good or bad for recognizing the colours of things by throwing a die; if it comes up six, the light will be undetectably unsuitable for recognizing colours by looking, but if it comes up any of one to five, the light will be suitable for exercising that capacity.21 Surely in this case too she has no business claiming to know the colour of something in one of the tests, even though the chances are now pretty good that if she says its colour is the colour it looks to have she will be right. Indeed, do the numbers matter 21 Ulf Hlobil suggested a case with this structure.

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at all? Suppose the experimenters tell her they will put her in their special lighting conditions in one in a hundred cases, or in one in a thousand. On any test occasion, she still confronts a specific possibility that the light has been engineered to be unsuitable for the capacity. Surely we have to say, even in these versions of the example, that for all she knows that possibility obtains; and, given her awareness of the way her capacity depends on the lighting conditions, it follows that in these circumstances she cannot claim to know the colours of things by looking, however good the chances are that if she names the colour something looks to her as if it has, she will be naming the colour actually had by the thing she is looking at. A high probability of being correct in what one says is not the right kind of thing to underwrite a claim to know something. Now suppose-no doubt fancifully, but it does not matter for the point I want to make-that statisticians quantify the fallibility of capacities to know colours by looking. Suppose they determine that people who are exercising such capacities are wrong about the colours of things in, on average, one case in a hundred. 22 And compare that with a version of the experimental case in which the story is that the experimenters will arrange for the light to be undetectably unsuitable for the capacity to 22 Here too I am following a suggestion by Ulf HlobiL

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know colours by looking in, on average, one test in a hundred. A good way to bring out what I am suggesting is to say that this match in numbers is irrelevant. When we imagine that fallibility might be quantified, we leave the sheer fact of fallibility, as before, posing no threat to the following idea: when all goes well in the exercise of a fallible perceptual capacity, its possessor is in a position that conclusively warrants her in believing something. The problem for the experimental subject, even in the version of the case in which the probabilities of being right are the same, is not the sheer fact of fallibility but a determinate possibility that the light is unsuitable for the capacity, a possibility that she cannot rule out, and that she would have to rule out if she was to be warranted in taking her perceptual state to one in which the thing's colour is visually present to her. Outside the context of the experiment, we have a subject who in ninety-nine cases in a hundred is in, and knows she is in, a perceptual state that provides conclusive warrant for a belief about the colour of something. In one case in a hundred, the fallibility of her capacity kicks in and she is wrong in taking herself to be in that position. But that does not require us to give up saying that she is in that position in the other cases. In the experimental case, in contrast, we have a subject whose warrant for a corresponding belie£ even on occasions on which

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the light is in fact suitable for knowing the colours of things by looking at them, at best makes it highly probable that it is true-which is not a sufficient warrant for her to count as knowing the colour of the thing she is looking at.

"~ I'

12. I have accused Burge of a blind spot for the possibility of a conception Sellars makes room for. When all goes well in the operation of a rational perceptual capacity, a subject is in a perceptual state that makes a feature of her environment present to her and so provides conclusive warrant for the corresponding belief. And it is not just that there is another option to set alongside the option of conceding that perceptual warrant cannot be better than inconclusive, the only option Burge considers. I do not think anyone would accept that a belief warranted by a perceptual state that leaves open a possibility that the belief is false could nevertheless count as knowledgeable, if that did not seem to be the only possible way to ensure that there is such a thing as perceptual knowledge. I£ as I have been urging, it is wrong to suppose there is no alternative, the idea can be simply dismissed; we can recognize that it does not really accommodate perceptual knowledge at all. If we suppose the warrant for a belief about the environment provided by a perceptual state cannot be better than inconclusive, what are our possibili-

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ties for thinking about knowledge through perception? There are essentially just two choices: scepticism, acknowledging that there is no such thing as perceptual knowledge, and dogmatism, claiming that an inconclusive warrant can be good enough for a belief it warrants to be knowledgeable. 23 But it is hard to see how dogmatism genuinely contrasts with giving in to scepticism. We are to grant that the warrant for a belief leaves open a possibility that the belief is false. I know no convincing explanation of how that can be made out to differ from granting that for all the believer knows her belief may be false. 24 I think the idea that a wedge can be driven there is no better than a philosophers' fantasy, sustained by the false conviction that it is the only possible way of purporting to avoid scepticism about perceptual knowledge. 13. I want to end by going back to a thought I broached near the beginning of this lecture, that knowledge as possessed by rational animals is a species of a genus, which is also instantiated in non-human animals and pre-rational human children. The idea of the genus matters to Burge's rejection of an epistemology that treats perceptual 23 See James Pryor, "The Skeptic and the Dogmatist'; Nous 34.4 (2000), 517-49. 24 See Rod!, Self-Consciousness, 146-51.

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knowledge as enjoyed by rational animals differently from perceptual knowledge as enjoyed by non-rational animals. I want to end with a couple of points about this. Much of Burges motivation for resisting this kind of epistemology is that he thinks it leads its proponents to give insufficient respect to a body of illuminating work in empirical psychology. The first point is that this is misplaced. Perceptual capacities, rational or not, are modes of responsiveness to features of an animal's distal environment that are strikingly underdetermined by impingements on sensory nerve endings in the animal's perceptual equipment. That poses a set of questions about how that perceptual equipment extracts information-as it is natural to say-about the distal environment, of course fallibly, from those immediate sensory impacts. Such questions arise no less urgently for rational perceivers than for non-rational perceivers. And in many cases they are answered, for rational perceivers, by theories that apply also to non-rational perceivers: theories of, for instance, how the visual systems of mammals, or even visual systems that are more widely shared, come to represent aspects of an animal's visible environment in response to the impingements of light on its retinas. The perceptual knowledge that is explained by such theories is typically not restricted to rational perceivers.

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Now it would be wrong to think a focus on perceptual knowledge as a rational achievement commits us to deprecating inquiries that address those questions. It is a fine thing to know how the perceptual systems of human beings and other animals do their work. We could not have our capacities for perceptual knowledge if we did not have perceptual systems whose operations are a topic for that kind of inquiry. But knowing how perceptual systems work is not a substitute for getting straight about perception as a self-consciously possessed and exercised capacity for knowledge. The second point is this. Burge in effect allows the idea of knowledge that is reason at work to apply only to knowledge from reasoning. If we follow him in that, we encourage a conception of reason that separates it from our animal nature. Burge speaks deprecatingly of an outlook in which "God-like critical reasoners" are "paradigms for human cognition': 25 Fairly enough, he complains that such an outlook makes it hard to accommodate human perceptual knowledge, which is not a matter of God-like critical reasoning. But his suggested remedy is to insist on keeping reason, in a sense in which reason is special to human beings, out of our account of human perceptual knowledge. That leaves unchallenged the idea that where reason is 25 "Perceptual Entitlement'; 504.

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operative in human knowledge, it is by way of our capacities for God-like critical reasoning. Now this can make it difficult to make satisfactory sense of the ancient idea that mature human beings are rational animals. Perhaps it is all right to suppose that reason makes us God-like. But if that is the whole of the difference we take reason to make, it becomes hard to integrate reason with animality. There is no such difficulty if we see capacities that belong to reason as operative in our form of responsiveness, mediated by the senses, to features of our environment. Perception as an operation of rationality is our distinctive species of something that is generically animal.

The> ..Aquinas LeCfures 1937-2011 14. St. Thomas and the World State. Robert M. Hutchins (1949) ISBN 0-87462-114-3 15. Method in Metaphysics. RobertJ. Henle, S.J. (1950) ISBN 0-87462-115-1 16. Wisdom and Love in St. Thomas Aquinas. Etienne Gilson (1951) ISBN 0-87462-116-X 17. The Good in Existential Metaphysics. Elizabeth G. Salmon (1952) ISBN 0-87462-117-8 18. St. Thomas and the Object ofGeometry. Vincent E. Smith (1953) ISBN 0-87462-118-6 19. Realism And Nominalism Revisited. Henry Veatch (1954) ISBN 0-87462-119-4 20. Imprudence in St. Thomas Aquinas. Charles J. O'Neil (1955) ISBN 0-87462-120-8 21. The Truth That Frees. Gerard Smith, S.J. (1956) ISBN 0-87462-121-6 22.St. Thomas and the Future ofMetaphysics. Joseph Owens, C.Ss.R. (1957) ISBN 0-87462-122-4 23. Thomas and the Physics of1958: A Confrontation. Henry Margenau (1958) ISBN 0-87462-123-2 24. Metaphysics and Ideology. Wm. Oliver Martin (1959) ISBN 0-87462-124-0 25. Language, Truth and Poetry. Victor M. Hamm (1960) ISBN 0-87462-125-9 26. Metaphysics and Historicity. Emil L. Fackenheim (1961) ISBN 0-87462-126-7 27. The Lure of Wisdom. James D. Collins (1962) ISBN 0-87462-127-5 28. Religion and Art. Paul Weiss (1963) ISBN 0-87462-128-3 29. St. Thomas and Philosophy. Anton C. Pegis (1964) ISBN 0-87462-129-1

THE AQUINAS LECTURES

Published by the Marquette Universiry Press Milwaukee WI 53201-1881 USA http://www.mu.edu/ mupress/ 1. St. Thomas and the Life ofLearning. John F. McCormick, S.J. (1937) ISBN 0-87462-101-1 2. St. Thomas and the Gentiles. Mortimer J. Adler (1938) ISBN 0-87462-102-X 3. St. Thomas and the Greeks. Anton C. Pegis (1939) ISBN 0-87462-103-8 4. The Nature and Functions ofAuthority. Yves Simon (1940) ISBN 0-87462-104-6 5. St. Thomas and Analogy. Gerald B. Phelan (1941) ISBN 0-87462-105-4 6. St. Thomas and the Problem of Evil. Jacques Maritain (1942) ISBN 0-87462-106-2 7. Humanism and Theology. Werner Jaeger (1943) ISBN 0-87462-107-0 8. The Nature and Origins of Scientism. John Wellmuth (1944) ISBN 0-87462-108-9 9. Cicero in the Courtroom ofSt. Thomas Aquinas. E.K. Rand (1945) ISBN 0-87462-109-7 10. St. Thomas and Epistemology. Louis-Marie Regis, O.P. (1946) ISBN 0-87462-110-0 11. St. Thomas and the Greek Moralists. VernonJ.Bourke (1947) ISBN 0-87462-111-9 12.History ofPhilosophy and Philosophical Education. Etienne Gilson (1947) ISBN 0-87462-112-7 13. The NaturalDesirefor God. William R. O'Connor (1948) ISBN 0-87462-113-5 "

I

T(,e> ..Aquinas Letlures 1937-2011 30. The University in Process. John O. Riedl (1965) ISBN 0-87462-130-5 31. The Pragmatic MeaningofGod. Robert O.Johann (1966) ISBN 0-87462-131-3 32. Religion and Empiricism. John E. Smith (1967) ISBN 0-87462-132-1 33. The Subject. Bernard Lonergan, S.]. (1968) ISBN 0-87462-133-X 34. Beyond Trinity. BernardJ. Cooke (1969) ISBN 0-87462-134-8 35. Ideas and Concepts. Julius R. Weinberg (1970) ISBN 0-87462-135-6 36. Reason and Faith Revisited. Francis H. Parker (1971) ISBN 0-87462-136-4 37. Psyche and Cerebrum. John N. Findlay (1972) ISBN 0-87462-137-2 38. The Problem of the Criterion. Roderick M. Chisholm (1973) ISBN 0-87462-138-0 39. Man as Infinite Spirit. James H. Robb (1974) ISBN 0-87462-139-9 40. Aquinas to Whitehead: Seven Centuries of Metaphysics of Religion. Charles Hartshorne (1976) ISBN 0-87462-141-0 41. The Problem of Evil. Errol E. Harris (1977) ISBN 0-87462-142-9 42. The Catholic University and the Faith. Francis C. Wade, S.J. (1978) ISBN 0-87462-143-7 43. St. Thomas and Historicity. Armand]. Maurer, C.S.B. (1979) ISBN 0-87462-144-5 44. Does God Have a Nature? Alvin Plantinga (1980) ISBN 0-87462-145-3

T(,e> ..Aquinas Letlures 1937-2011 45. Rhyme and Reason: St. Thomas and Modes of Discourse. Ralph Mcinerny (1981) ISBN 0-87462-148-8 46. The Gift: Creation. Kenneth L. Schmitz (1982) ISBN 0-87462-149-6 47. How Philosophy Begins. Beatrice H. Zedler (1983) ISBN 0-87462-151-8 48. The Reality of the Historical Past. Paul Ricoeur (1984) ISBN 0-87462-152-6 49. Human Ends and Human Actions: An Exploration in St. Thomas' Treatment. Alan Donagan (1985) ISBN 0-87462-153-4 50. Imagination and Metaphysics in St. Augustine. Robert O'Connell, S.J. (1986) ISBN 0-87462-227-1 51. Expectations of Immortality in Late Antiquity. Hilary A Armstrong (1987) ISBN 0-87462-154-2 52. The Self Anthony Kenny (1988) ISBN 0-87462-155-0 53. The Nature of Philosophical Inquiry. Quentin Lauer, S.]. (1989) ISBN 0-87562-156-9 54. First Principles, Final Ends and Contemporary Philosophical Issues. Alasdair Macintyre (1990) ISBN 0-87462-157-7 55. Descartes among the Scholastics. Marjorie Greene (1991) ISBN 0-87462-158-5 56. The Inference That Makes Science. Ernan McMullin (1992) ISBN 0-87462-159-3 57. Person and Being. W. Norris Clarke, S.J. (1993) ISBN 0-87462-160-7 58. Metaphysics and Culture. Louis Dupre (1994) ISBN 0-87462-161-5

The' -Aquinas Ledures 1937-2011 59. Medi~val Reactions to the Encounters between Faith and Reason. John F. Wippel (1995) ISBN 0-87462-162-3 60. Paradoxes of Time in Saint Augustine. Roland J. Teske, S.J. (1996) ISBN 0-87462-163-1 61. Simplicity As Evidence of Truth. Richard Swinburne (1997) ISBN 0-87462-164-X 62. Science, Religion and Authority: Lessons from the Calileo Affair. RichardJ. Blackwell (1998) ISBN 0-87462-165-8 63. What Sort of Human Nature? Medieval Philosophy and the Systematics of Christology. Marilyn McCord Adams (1999) ISBN 0-87462-166-6 64. On Inoculating Moral Philosophy against Cod. John M. Rist (2000) ISBN 0-87462-167-X. 65. A Sensible Metaphysical Realism. William P. Alston (2001) ISBN 0-87462-168-2. 66. Eschatological Themes in Medieval Jewish Philosophy. Arthur Hyman (2002) ISBN 0-87462-169-0 67. Old Wine in New Skins. JorgeJ. E. Gracia (2003) ISBN 0-87462-170-4. 68. The Metamorphoses of Phenomenological Reduction. Jacques Taminiaux (2004) ISBN 0-87462-171-2. 69. Common Sense: A New Look at an Old Philosophical Tradition. Nicholas Rescher (2005) ISBN-1O:0-87462172-0; ISBN-13:978-0-87462-172-3. 70. Five Metaphysical Paradoxes. Howard P. Kainz (2006) ISBN: 0-87462-173-9; ISBN-13: 978-0-87462-173-0. 71. St. Thomas and Form as Something Divine in Things. Lawrence Dewan, OP (2007) ISBN978-0-87462-174-7. 72. Aristotle's Divine Intellect. Myles F. Burnyeat (2008) ISBN 978-0-87462-175-4.

The' -Aquinas Ledures 1937-2011 73. What Happens after Pascal's Wager: Living Faith and Rational Belief Daniel Garber (2009) ISBN 978-087462-176-1. 74. What Is Reparative Justice? Margaret Urban Walker (2010) ISBN 978-0-87462-177-8. 75. Perception as a Capacity for Knowledge. John McDowell (2011) ISBN 978-0-80462-178-5.

About the Aquinas Lecture Series

The Annual St. Thomas Aquinas Lecture Series began at Marquette University in the spring of 1937. Ideal for classroom use, library additions, or private collections, the Aquinas Lecture Series has received international acceptance by scholars, universities, and libraries. Hardbound in maroon cloth with gold stamped covers. Uniform style. Some reprints with soft covers. Complete set (ISBN 0-87462-150-X ) receives a 40% discount. New standing orders receive a 30% discount. Regular reprinting keeps all volumes available. Ordering information (purchase orders, checks, and major credit cards accepted): Marquette University Press Phone: (800) 247-6553 or order online at: http://www.mu.edu/mupress/ Editorial Address: Dr. Andrew Tallon, Director Marquette University Press P.O. Box 3141 Milwaukee WI 53201-3141 Tel: (414) 288-1564 FAX: (414) 288-7813 email: [email protected]