Churchland Again: How to Duck Some Objections

Other minds have been debating my Churchland post over at DuckRabbit, attributing to a certain H.A. Monk (a name I have assiduously but unsuccessfully tried to excise from this blog, since it is internally related to my identity on my other blog, The Parrot's Lamppost) various assertions that concede a bit too much to both materialist and Cartesian views on the mind-body problem. Though the discussion seems to have ended up in a debate on ducks and rabbits (which I thought would have been settled long ago on that site; in any case, see my "Aspects, Objects and Representations" - in Carol C. Gould, ed. Contructivism and Practice: Toward a Historical Epistemology, Rowman and Littlefield, 2003 - for yet another contribution to the debate) Duck's original post offers a number of points worth considering. (Have a look also at N.N.'s contribution at Methods of Projection. N.N. picked the right moniker, too, maybe because there are also two n's in "Anton".) Here is a version of what I take to be Duck's central criticism of what I said about Churchland:

It's true that the materialist answer "leaves something out" conceptually; but the reply cannot be that we can bring this out by separating the third-personal and first-personal aspects of coffee-smelling, and then (by "turn[ing] off a switch in his brain") give him only the former and see if he notices anything missing. That the two are separable in this way just is the Cartesian assumption common to both parties. (Why, for example, should we expect that if he simply "recognize[s] the coffee smell intellectually" his EEG wouldn't be completely different from, well, actually smelling it?) I think we should instead resist the idea that registering the "coffee smell" is one thing (say, happening over here in the brain) and "having [a] phenomenological version of the sensation" is a distinct thing, one that might happen somewhere else, such that I could "turn off the switch" that allows the latter, without thereby affecting the former. That sounds like the "Cartesian Theater" model I would have thought we were trying to get away from.

While I appreciate the spirit of this comment, I must say that I think it does not merely concede something to Churchland, it is more or less exactly what Churchland is saying, though you might want to add "seen through an inverting lens". Churchland indeed wants to deny that "the two are separable in this way"; in fact he takes an imaginary interlocutor sharply to task for asking him to provide a "substantive explanation of the 'correlations' [between "a given qualia" and "a given activation vector"]" because this "is just to beg the question against the strict identities proposed. And to find any dark significance in the 'absence' of such an explanation is to have missed the point of our explicitly reductive undertaking" (Philosophical Psychology 18, Oct .2005, p.557). In other words: if what we have here is really an identity relation - two modes of presentation of things that are exactly, numerically the same - how dare you insist that I should explain how they are related. They are related by being the same thing, Q.E.D.!

My post was largely directed as fishy moves like this. The problem is that we have two things that we can - and lacking any evidence to the contrary, must - identify (pick out, refer to) by two completely different procedures; yet Churchland wants to assert that they are identical. What notion of identity is at work here is hard to say. Since Churchland rejects the notion of metaphysical necessity it cannot be "same in all PW's". But it must be more than "one only happens when the other happens" since that is a mere correlation. Even "one happens if and only if the other happens" could mean nothing more than that some natural law binds the occurrence of the two things together, which does not give us numerical identity. He wants to say "blue qualia are identical to such-and-such coding vectors", and we have to take this as meaning more than that there is evidence for their regular coinstantiation. But to make it theoretically sound, or even plausible, in light of the fact that we recognize the two ideas in totally different ways, he must offer two things, at least: (1) an explanation of why these apparently distinct facts (qualia/coding vectors) are actually one and the same phenomenon (what makes the one thing manifest itself in such dissimilar ways); and (2) experimental evidence of an empirical correlation between them. Yet he also tells us that we are "begging the question" if we ask for an explanation! And as for the empirical correlation, it is not just that no one has sat down and examined a subject's cone cell "vectors" and asked them, "Now what color do you see?"; the fact is that the whole idea of "coding vectors" is a mathematical abstraction from a biological process that almost certainly only approximates this mathematical ideal, even before we get to the question of how regularly the outputs of the process end up as the particular color qualia that are supposed to have been encoded.

I am not saying there is no evidence at all for the analysis Churchland offers (based on the so-called "Hurvich-Jameson net" at the retinal level and Munsell's reconstruction of possible color experiences at the phenomenological level), but that there is not even evidence of a strict correlation. Some of the things that Churchland discusses - for example, the fact that this analysis of color vision is consistent with the stabilization of color experience under different ambient lighting conditions (p.539) - strongly suggest that something about the analysis is right, but do not constitute direct empirical evidence for it. What we are really being offered is a notion of identity that has as its basis neither metaphysics, nor scientific explanation, nor sufficient quantitative evidence to establish a strict correlation. We can be excused for saying "no thanks" to this libation.

And if this unanalyzed notion of the identity of phenomenological and biological facts is also being proffered in the name of some other philosophical position - say, Wittgenstein's - we should be no less skeptical. Merely proclaiming the lack of distinction between phenomenology and physiology, inner and outer, mind and world, something and nothing, etc. does not establish anything as a viable philosophical position on consciousness. Even adding the observation that one gets rid of philosophical problems this way does not establish it as a viable position. One gets rid of problems also by saying that god established an original harmony of thought and matter. If you can just swallow this apple whole, you'll find that the core goes down very easily.

Whoops, what happened to my erstwhile Wittgenstein sympathies? Well, maybe the apple I don't want to swallow is really this interpretation of Wittgenstein. Duck and I agree that being sympathetic to Wittgenstein does not require dismissing all scientific investigation of the brain (or the world in general) as irrelevant. But I don't think we agree on why. Duck quotes the following passage from the PI :

'Just now I looked at the shape rather than at the colour." Do not let such phrases confuse you. [So far so good; but now:] Above all, don't wonder "What can be going on in the eyes or brain?" ' (PI p.211)

What is Duck's view of this recommendation? He is not quite sure, but finally decides that philosophers' conceptual investigations will keep scientists honest, so they avoid causing problems for us philosophers:

In a way this is right... Don't wonder that... you thought that was going to provide the answer to our conceptual problem. But surely there is something going on in the brain! Would you tell the neuroscientist to stop investigating vision? Or even think of him/her as simply dotting the i's and crossing the t's on a story already written by philosophy? That gets things backwards. Philosophy doesn't provide answers by itself, to conceptual problems or scientific ones. It untangles you when you run into them; but when you're done, you still have neuroscience to do. Neuroscience isn't going to answer free-standing philosophical problems; but that doesn't mean we should react to the attempt by holding those problems up out of reach. Instead, we should get the scientist to tell the story properly, so that the problems don't come up in the first place.

For my part I don't think this is the point of Wittgenstein's various proclamations about the independence of philosophy from science. Wittgenstein was concerned that physicalistic grammar intrudes into our conceptual or phenomenological investigations, making it impossible to untangle and lay out perspicuously the grammar of phenomena. This is the root of what we call "philosophical problems". It is not the scientist who we have to get to "tell the story properly", it is the philosopher. The scientist does not have a fundamental problem with importing the grammar of phenomenology, thereby tying her physical investigations into knots. It is the other way around: the magnetic pull of physical concepts constantly threatens to affect conceptual investigation. To take a slightly oversimplified example, we say we can "grasp" a thought, but it is an imperceptible step further along the path of this metaphor that allows us to think we can capture it concretely - say, in a proposition, or a sentence of "mentalese" - in a sense that depends quite subtly on our ability to "grasp" a hammer or the rung of a ladder (picking it out as a unique object, self-identical through time, involved in a nexus of cause-effect relations, etc.). True, it takes quite a leap before you are ready to say, "The thought 'the cat is on the mat' just is this neuronal activation vector'", but that is one logical result of this sort of thinking. That we are ready to call this the solution to a philosophical problem just puts the icing on the cake; it is the dismissal of philosophy per se, in more or less the way we can dismiss morality by pointing out that we are all just physical objects made of atoms anyway, and who could care what happens to that?

When Wittgenstein says, "don't wonder, 'What can be going on in the eyes or the brain?'" he is using duck-rabbit-type phenomena to show that conceptual or psychological problems may not be tracked by any physical difference at all. In fact, there is a passage just after the one cited by Duck in which WIttgenstein lays it out as clearly as anyone could ask. He suggests a physical explanation of aspectual change via some theory of eye tracking movements, and then immediately moves to say,

"You have now introduced a new, physiological criterion for seeing. And this can screen the old problem from view, but not solve it". And again, he says, "what happens when a physiological explanation is offered" is that "the psychological concept hangs out of reach of this explanation" (p.212).

The point is very straightforward, and it is certainly compatible with what I have been saying about Churchland. The physical level of explanation just flies past the psychological concepts without recognizing or accounting for them. But in Duck's view, I am guilty of reintroducing the bogey of dualism and the "Carteisan theater" (I'm planning a post on Dennett soon so I'll avoid this bait right now):

So what's the moral? Maybe it's this. In situations like this, it will always seem like there's a natural way to bring out "what's missing" from a reductive account of some phenomenon. We grant the conceptual possibility of separating out (the referent of) the reducing account from (that of) the (supposedly) reduced phenomenon; but then rub in the reducer's face the manifest inability of such an account to encompass what we feel is "missing." But to do this we have presented the latter as a conceptually distinct thing (so the issue is not substance dualism, which Block rejects as well) – and this is the very assumption we should be protesting. On the other hand, what we should say – the place we should end up – seems in contrast to be less pointed, and thus less satisfying, than the "explanatory gap" rhetoric we use to make the point clear to sophomores, who may very well miss the subtler point and take the well-deserved smackdown of materialism to constitute an implicit (or explicit!) acceptance of the dualistic picture.

Absolutely, a physical explanation or description of consciousness is "conceptually distinct" from a phenomenological one. I can see no other possible interpretation of the passage about the eye-movement explanation of "seeing-as" phenomena. Does this make Wittgenstein a "dualist"? Certainly not in the Cartesian sense. True, Wittgenstein not only studied architecture and engineering and cited Hertz and Boltzmann in his early work; he also read (and failed to cite) Schopenhauer and James and had a deep appreciation of "the mystical", which he further identifies with "the causal nexus"; he says in the TLP that philosophy should state only facts, and that this shows how much is left out when all the facts have been stated. But is he now going so far as to suggest that there are different worlds, of scientific and mental reality? I seriously doubt it; and neither am I. There are different levels of explanation, or in his own terminology, different language games. This is not a Cartesian dualism but a point about the structure of thought. It is the same point that much of the Blue Book is based on.

I have not said much about my view of consciousness in this blog. But we're only just getting started, I've got time. I will say this, though: the resolution of the mind-body problem cannot be as simple as, for example, the New Realist (or "neutral monist") school hoped it would be. There, various aspects of reality were said to consist of a single "stuff" (read "substance", with various proposals for what this would be circulating at the time) which took on physical or psychological "aspects" depending on our interest, point of view, or whatever. This is a nice, compact view, but it does not do justice to the issue. There is a brain without which there is nothing in the world called "thinking", and a world without which nothing in a brain can count as "thought". There is every reason to believe that every event that ever counted as a thought took place in a brain, and that something was going on in the brain without which that thought would not have happened. This all has to be accounted for, and it is not sufficient to say that there are different aspects to some general substance or process. Sure, there are different aspects to everything, but this won't get us very far with the mind-body problem. How did an "aspect" of something that is also matter end up as consciousness? The problem is only pushed back. How can an "aspect" of whatever be self-aware, control its own actions, or compose a piano sonata? These are very peculiar aspects. If we could put them under an electron microscope we would not find out what we want to know about them.

I suspect that something like the following is the case: the various phenomena we call "the mind" are asymmetrically dependent on the brain, but the relationship is so loose that there is never anything like the "identity" relationship Churchland wants, nor a mere difference in points of view between the physical and phenomenological "aspects". We recognize certain psychological phenomena and talk about them and analyze them, and there is no such thing as a specifiable set of neural events that are necessary and sufficient for the instantiation of these phenomena - perhaps not even as types, and certainly not as specific thoughts, volitions, etc. There may be some wave oscillations in the brain that correspond to conscious states, but they are not those conscious states. There are particular portions of the brain that are primarily involved in certain aspects of our intellectual activity - emotions, language, memory, etc. - but there is not a specifiable neural "vector" that is "identical" to Proust's sensation of the taste of his mother's "sweet madeleines", much less to the flood of memories it evokes. Perhaps in Churchand's utopia we can replace Swann's Way with some mathematical specifications of its underlying neural activity without any particular loss, but I am not holding my breath.

Why do I think this, or even have a right to hold it out as a reasonable objection? Just because I think psychological concepts are not he rigid, well-articulated concepts that you find in much analytic philosophy. There is a way you can talk about things that are not uniquely or cleanly definable (Wittgenstein: "You are not saying nothing when you say 'stand roughly there...'"; a quote that is roughly accurate!). Talking about them is intellectually interesting in philosophy, important in clinical psychology and ethics, satisfying in the arts. It has been recognized by some neuroscientists and philosophers (Varela and others) that unless you have some kind of scientific phenomenology to begin with, you can't hope to reduce anything to neurology. But that position presupposes that there is something like a science of folk psychological concepts, on something like the lines that Husserl, Sartre and others tried to give us. And Wittgenstein too, in a certain sense: only his phenomenology of mind is imbued with the understanding that part of the "science" we are looking for involves the recognition of the vagueness or circumstantial relativity of concepts.

So how about a vague specification of cone cell coding vectors? "There is a 95% correlation between this coding vector and observed reports of red sensations." I could live with that. But it still doesn't give us a claim to "identity", nor does it justify saying that these are different "aspects" of the same event. They are different things that generally must happen
in order to recognize something as red. But I can say I dreamed of a red balloon and no one will say, "Oh, but there were no cone cell vectors, you couldn't have." And of course even my memory of a red balloon is a memory of something viscerally red, with no conce cell activity to show for it.

Brain Freeze, or Churchland on Color Qualia

It's been two months since I posted anything here, which is not how it was supposed to go. I have some excuses: replies to three papers at two recent philosophy conferences, a lack of breaking news on the cog sci front, and some personal stuff that I won't get into. Anyway, the last of the conference papers was concerned with a relatively recent paper by Paul Churchland, in which he argues for the "identity" of color "qualia" (an obnoxious Latinate neologism that philosophers use to refer to our mental experience of colors) with "cone cell coding triplets" or "vectors" - an analytic description of how the eye reacts on the cellular level to light of various wavelengths. Churchland further asserts that based on this analysis he can make certain predictions about our color experience in unusual cases, a feat that, according to him, is usually assumed to be beyond the power of materialist identity theories. That is the main point here; the identity of (a) the experience, and (b) the biochemical basis of the reaction, is said to not only account for ordinary experiences like seeing red, but for experiences which most people have not had. Churchland describes how to produce such experiences and provides various full-color diagrams to assist. The predictive power of the theory allegedly shows that the qualia-coding vector relationship is not a mere correlation but an actual identity.

It is not impossible that some philosophers have carelessly suggested that materialism cannot be true because it cannot make predictions about experience. But to rest the case against materialism on this narrow basis is a very bad idea, for the simple reason that there are straightforward and well known areas in which knowledge of the physical structure of the body allows you to make specific phenomenological predictions. For example, recently it was discovered that glial cells, which make up much of the central nervous system, contribute to severe or chronic pain by stimulating the pain-transmitting neurons. Prediction: find a drug that deactivates the glial cells, and with or without more traditional pain-relief methodologies (e.g., those which interfere with the transmission of signals across nerve synapses or attempt to freeze the nerve itself) the patient will feel less pain. There is a perfectly good phenomenological prediction from neurological facts.

And there are even easier cases. We know that the lens of the eye delivers an inverted image, which is subsequently righted by the brain. This suggests that our brains, without our conscious effort, favor a perspective that places our heads above our feet. (It is also possible that it is simply hard-wired to invert the image 180 degrees, but for various reasons that theory does not hold water.) Prediction: make someone wear inverting glasses, and they will see un upside down image at first (the brain inverts it out of habit), but eventually the brain will turn it right side up. It works!

And it gets even easier. After all, there were times long ago when we did not know anything about the internal structure of sense organs. Our auditory capabilities rest on the action of thousands of tiny receptors lodged in hair cells in the Organ of Corti, part of the cochlea of the inner ear. Prediction: dull the function of these receptors and and the subject will experience a loss of hearing. Wow, another phenomenological prediction. I'm sure you could go hog wild with this. Poke your left eye out and you will see in diminished perspective, an amazing prediction in itself. Practice seeing through one eye for a long time and your sense of perspective should increase. Such predictions differ a lot from an example that Churchland presents in another context, that trained musicians "hear" a piece differently than average audiences. That is also a predictable phenomenological fact, but it involves a change in the mental software, through accustomization and training, and does not obviously involve any sensual change. To see a new color or to have fewer distinct sounds reach the brain from the cochlea are sensual changes; to hear more deeply those sounds that do reach the ear, to organize them more efficiently and recognize more relationships between is not a sensual change but an intellectual one that we might metaphorically characterize as "hearing more than others". In fact musicians hear the same thing others hear but understand what they hear in a more lucid way. The sensual phenomena I have mentioned are actual changes in what reaches the brain for processing or in processing at a subliminal level, and do not depend on how we train ourselves to organize the information we receive.

I admit that my predictions are not very interesting; they operate at a more macro level than Churchland's strange color qualia, though not as macro as the following: cut out someone's tongue and they won't taste much. That's about like: cut out someone's brain and they won't think much. That may sound pretty obvious, but it wasn't always. Churchland is playing on the fact that intimate knowledge of how vision works is a relatively recent and still growing science. Thus it sounds like quite an amazing feat that he should be able to "predict" color "qualia".

But actually, although his predictions are more refined than mine, digging deeper into more subtle properties of the visual system, they are no more predictions of "qualia" than the general statement: interfere with some physical property of a sensory apparatus and you will change the sensations experienced by the subject. Refining this down to a specific phenomenological experience does not get closer to predicting "qualia", it merely makes a more specific prediction based on a fairly well fleshed out physical theory. It is roughly at the level of first discovering certain facts about the eye and then discovering that those facts are consistent with seeing a green after-image when exposed to a flashbulb. "I predict a green qual!" Okay, that's a little better than "I predict the stock market with crash - some time..." But it doesn't really do much for materialism. (And I'm not even talking about "eliminative" materialism here, which I said I'd refuse to take seriously, just the more typical materialist identification of experience with physical facts.)

Why? We could gloss Churchland's prediction as follows: "I predict that if you look at this in the right way you will have that experience that is commonly understood to be going on when a person utters the words, 'I see green'". And what is that? Just the very thing that non-materialists bring up as an "explanatory gap". Churchland can't predict we will have particular qualia because he doesn't have even so much as a theory as to what the relationship is between qualia and their scientific background. He seems to think that a correlation which has predictive accuracy is eo ipso an identity relation. But this is just another brain scam. One might say: qualia are a suspect kind of entity anyway, so why should I need a theory to account for them? Fine, but what you can't say is: these qualia you talk about, they just are these coding vectors, and then act like you've explained qualia. For example, suppose you were to say: these UFO's you talk about, they just are marsh gas. Okay, you've explained away UFO's. But you surely haven't explained UFO's. You've submitted the thought: until and unless you give me some specific physical evidence that there are these things, "UFO's", that cannot be explained by any other consistent set of physical facts except that secret aircraft controlled by animate beings are navigating our skies, I deny that UFO's exist as a category of object requiring independent explanation. Similarly, one can say: I can explain everything there is to explain about sensation without reference to "qualia", so why should I be obliged to give you a separate explanation of them? But that is not what is being offered. Rather, we are told, color qualia exist; they are cone cell coding vectors.

"Laughter exists; it is... [insert physical description of lung contractions and facial expressions]"
"Orgasm exists; it is... [insert physical descriptions of male or female anatomical changes during orgasm]"
"Aesthetic appreciation exists; it is... [insert data from brain scans of people listening to Mozart]"
"Religious rapture exists; it is... [insert data from brain scans of people talking in tongues]" (this has actually been studied, by the way)

When is Churchland going to wake up and smell the coffee? I'm not sure, but I don't think we should test it by asking him whether he's awake or not; better check his brain scan and let him know. Then do an EEG and see if he's smelling the coffee. With sufficient training he could be taught to look at the EEG and say, "Why, I was smelling coffee!" (This is the flip side of Churchland's utopia, in which we are all so well-informed about cognitive facts that introspection itself becomes a recognition of coding vectors and the like.) Now for the tricky part: turn off the switch in his brain that produces the coffee-smelling qual, and tell him that every morning, rather than having that phenomenological version of the sensation, he will recognize the coffee smell intellectually and be shown a copy of his EEG. And similarly, one by one, for all his other qualia.

Don't say: well, he doesn't deny these qualia exist, after all; he just thinks they are identical to blah-blah-blah... If he thinks they are identical to blah-blah-blah then he should not object in the least if we can produce blah-blah-blah without those illusory folk-psychological phenomena we think are the essence of the matter. So, on with the experiment. Where do you think he will balk? When we offer to substitute a table of coding vectors for the visual quals of his garden in springtime? An EEG for the taste of grilled tuna? Maybe a CAT scan of soft tissue changes rather than the experience of orgasm? I'd really like to know just how far he is willing to go with this. Would he wear one of those virtual reality visors, having in the program only charts and graphs and other indicators of brain and body function? Maybe Churchland is the only one among us who really understands how to have fun. Personally, I'll keep my red roses, my grilled tuna taste, and... the other stuff, thanks.