Markie and Dretske on Appearances

Over coffee yesterday, Peter told me of the following Dretske view (it’s in one of the recent Blackwell volumes edited by Steup, I think, but I don’t recall which one Peter said). To be appeared to banana-ly, one must be appeared to yellow-ly and some-particular-shape-ly. The banana appearance causes the belief that the object is a banana, and the other appearances cause their respective beliefs as well. So the banana belief is noninferential, but it depends on the more basic perceptual states in a way that requires for its justification some reason to think that yellow things shaped in this particular way are usually bananas.

Peter and I thought this account mistaken. It is true that there are basic perceptual properties, such as color ones, and non-basic perceptual properties, such as those involving natural kind terms. It may also be a necessary truth, at least for beings who learn from perceptual mechanisms. The initial cognitive activity of a belief-forming system relies on the existence of the basic properties, and uses these to develop the ability to perceive non-basic properties. This etiological point may also carry on throughout the life of the belief-forming system, so that in every case of perceiving non-basic properties, the basic ones are there as well and the non-basic ones depend at that very moment on the basic ones. Dretske describes this dependence as, according to Peter, “logical dependence”, and presumably means to contrast this kind of dependence with the etiological point made earlier.

But the logical dependence point is mistaken, both of us thought.

There’s no reason I can see why a perceptual system can’t be designed so that you have to climb a conceptual ladder in order to acquire the capacity to perceive non-basic properties, a ladder the first rung of which involves basic perceptual properties. But once one has climbed enough to be able to perceive non-basic properties, it’s not clear why the basic ones can’t just disappear. I think we’re somewhat familiar with this phenomenon from thinking about the artist’s perception of a scene versus our own. We see visually stunning sunset, and the basic color properties of the scene have to be reconstructed with some difficulty, rather than being there in one’s phenomenology all along. More generally, there’s no reason to think that a system can’t be designed to function this way, even if we don’t. The system has to develop it’s perceptual capacities from basic perceptual abilities, but once it does, there’s no reason to think that the non-basic perceptions require the presence of the basic ones anymore (even if this is a psychological fact about us).


Comments

Markie and Dretske on Appearances — 7 Comments

  1. This is a very interesting issue, Jon. Let me see if I am clear about what you claim to be possible. Is it that we might start out perceiving Bs (bananas, e.g.) by having perceptions with intrinsic visual characteristic Y (yellowish, being appeared to yellowly, what have you) plus others, but later we learn to perceive Bs even though we’ve lost the ability (or the opportunity) to have perceptions with intrinsic character Y? Thus perceiving Bs does not logically require the presence of Y experiences. That seems right, but would we still be perceieving them as Bs that are Y (yellow bananas) even if we could say, and believe, “ripe (but not overripe) bananas are yellow”? I may be completely off track here about your suggestion, though.

    It seems to me that our ability to perceive Bs will still require the presence of symptomatic perceptual experiences of some sort. What may be radical, but true, is that the intrinsic properties of the experiences are irrelevant: it’s what they are OF or ABOUT that enables us to use them in the identification of Bs. So if there is a systematic correlation of the presence of Bs with experiences having any intrinsic features X (fill in the blank), having X experiences will provide us with the ability to perceive Bs, indeed will be experiences OF Bs, no matter what their intrinsic character. (I wish this were an original suggestion but it is developed in detail with an ingenious thought experiment in Paul Churchland’s *Scientific Realism and the Plasticity of Mind* by means of an ingenious thought experiment that has, to my knowledge, received surprisingly little discussion in the literature. As I recall, Churchland’s view was, in turn, suggested by a JPhil article by Feyerabend called “Science Without Experience.” I keep meaning to get around to discussing this material in greater detail…)

  2. Andy, it is true that one’s perceptual field will still include the color and shape that Dretske refers to. That’s not sufficient for the phenomenology to be as he describes, however, and working through the problem of the speckled hen shows that at a minimum the phenomenology involves attending to features of the perceptual field. That’s what I was thinking when I said the logical dependence claim was false–the color and shape will still be there, but not attended to in the way required for them to play a role in the phenomenology.

  3. Dretske’s paper in the Steup-edited volume (Contemporary Debates in Epistemology) is on closure. I don’t remember it having anything about this issue — though I may be forgetting, and I only briefly re-skimmed it to see. Perhaps what Peter Markie was thinking of is Dretske’s entry on ‘Perceptual Knowledge’ in the 1992 Blackwell Companion to Epistemology? It’s a really interesting paper. There Dretske does express a view like the one you attribute to him, though he doesn’t mention appearances or phenomenology at all. Of course I’m no expert on the Dretske corpus, so perhaps there’s another more recent paper of his I haven’t read that contains the relevant material.

    His argument there that my knowledge that there’s a banana before me is “indirect, dependent or derived” is that such knowledge is “derived from the more basic facts we use to make the identification. In this case the facts we come to know about it [to wit, that it’s a banana] are different than the facts that enable us to know it”. So we see that it’s a banana by seeing that it’s yellow and banana-shaped. By contrast (I guess), we see that it’s yellow by seeing that it’s yellow — hence that knowledge is direct.

    In any event, I agree with your criticism, and I think it works against Dretske even if it’s not couched in terms of appearances. I think it’s just not true that I see that something’s a banana (in part) by seeing that it’s yellow, even if I did at one point. And even if I did, if I don’t infer that it’s a banana from seeing that it’s yellow, the sense in which the former seeing depends on the latter seems to me to be a purely causal one, leaving it up in the air just what epistemological import this dependence relation has.

    One comment: the argument you give for the distinction between basic and non-basic properties leaves it (I think) a contingent matter of psychology just what the basic properties represented in perception are. As long as you’ve got some set of properties a creature is naturally set up to perceive, you can use those to learn to perceive other properties. This is very interesting, though some (including you?) might want to avoid it, because it means there is no special epistemic feature (like indubitability, transparency, or whatever) the basic properties need to have. It also means that you can’t be so quick to say that properties involving natural-kind terms aren’t basic. We might be set up in such a way that we perceive that something’s water, or that someone’s angry (or, in appearance-talk, appearing watery and appearing angry might be basic perceptual properties), and that we never learn to perceive these properties by perceiving other, more basic properties. Indeed, I think it’s highly likely that that is the case.

  4. Geoff, I agree that it is a contengent matter of psych. just what the basic properties are, and that it is contingent whether experience of nonbasic properties remains dependent on experience of basic properties. And any claim about natural kind terms not indicating basic properties would also be a contingent claim, though I think a true one for natural kind terms like “banana” and “water”. I take it you think otherwise, but if that were true, I don’t see why we can test infants for color perception and find out that they detect differences, but we wouldn’t be able to do so for natural kind terms. To set up the experiments, you’d have to make sure that the infant was detecting the property in question, rather than some associated property (such as color or shape), but one you control for those factors, I’d bet the farm that the infant won’t pass the test.

  5. Jon,

    I was thinking that the argument you give in the original post shows (if it’s sound) that creatures who can learn to perceive properties must come “built in” with the ability to perceive a certain set of properties. These are the “basic” ones. You imply in your comment that these are also the properties we’re born being able to perceive. But it seems plausible to me that there are some properties we can’t perceive ex utero but which, given normal brain development, we acquire the ability to perceive later on — not as the result of learning in the way that we learn what a banana is but as something more akin to learning a language, which you do more-or-less automatically given the right stimuli. I would lump such properties together with the basic ones like being red and being round, rather than with non-basic ones like being a skyscraper or being a jellyfish. (As for “banana”, I’m pretty sure it’s non-basic; “water” I’m less sure about. “Angry” and “happy” and “wants x” I’m think are basic in this sense; same with “human” and “face”. I’m don’t know whether those are natural kind terms, but they’re not color and shape terms, either.)

    It seems to me that the philosophically interesting distinction between basic and non-basic properties is here; our knowledge about properties we’re naturally set up to perceive is “direct” and “noninferential” if any knowledge is.

    Note too that some people think (and there’s evidence to suggest) that infants can discriminate between red and orange some months before they can discriminate between different shades of red — even when the differences in the wavelengths between the two pairs of colors are the same. If you think that the basic properties are whatever ones we’re born being able to perceive, this would put pressure on you to say that “red” and “orange” are basic but “scarlet” and “crimson” are not. Maybe that’s fine; I would think it more natural to say that all the colors are equally basic, even if we have to wait a little while to be able to perceive some of them.

  6. Geoff, I don’t think I said or implied that basic properties are ones one is born having the capacity to detect, though I do think that such beings are possible. I’m not sure what in the above led you to think I held that view, but I hereby renounce it thoroughly… I did mention initial cognitive activity, but that has no logical connection with birth.

  7. Jon,

    Sorry, I was sloppy. You are of course right that cognitive activity need not begin at birth. I shall try to put the point more carefully.

    If you are a creature who is able to learn to perceive new properties, there must be some set of properties you can perceive without learning how to do so. That strikes me as a plausible claim, and it suggests a nice criterion for distinguishing between basic and nonbasic perceptual properties: those one learns how to perceive are nonbasic, and those one does not are basic. Now there might be properties you can perceive without learning how to perceive them, and yet which you cannot perceive at the beginning of your cognitive life — you just automatically acquire the ability to perceive them as you develop. If there are such properties, then according to the criterion they are basic. But then the fact (if it is a fact) that infants of a certain age can distinguish between red and blue but not between water and milk does not show that being water is not perceptually basic.

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