Saturday, December 26, 2009

Churchland on dualism, Part II

Let’s continue our look at Paul Churchland’s critical discussion of dualism in his textbook Matter and Consciousness. I have noted that while Churchland neglects even to mention the most important arguments for dualism and devotes space to arguments that dualist philosophers themselves don’t actually put much stock in, he does at least discuss two arguments that many such philosophers do think important: the argument from introspection and the argument from irreducibility.

As Churchland summarizes the argument from introspection, it states that the thoughts, sensations, desires, and emotions we encounter in introspection are just plainly different from electrochemical activity in neural networks. As he summarizes the argument from irreducibility, it states that language, reasoning, the introspectible qualities of sensations, and the meaningful contents of our thoughts cannot plausibly be accounted for in materialist terms; for example, knowledge of the molecular structure of a rose and/or of the brain would not allow a physicist or chemist to predict what it would be like to experience the smell of a rose.

Churchland’s summary of these arguments is superficial. For example, it is clear from his gloss on the argument from irreducibility that he regards Frank Jackson’s famous “knowledge argument” as an important instance of it. Yet he does not actually state Jackson’s argument, thus denying the unwary reader an opportunity to appreciate its full power. (Churchland does briefly discuss Jackson’s argument later in the book, but only after having disposed of dualism and plumped for materialism, thus giving the misleading impression that the argument is merely a puzzle an already-established materialism must solve rather than an independent argument for dualism in its own right.)

Worse than this, though, are the responses he gives to the two arguments in question, which are presented as decisive but are in fact exceedingly feeble. The argument from introspection has no force, Churchland assures us, because introspection cannot be trusted in light of the fact that there are clear cases from the history of science showing that our natural powers of observation have misled us in other domains. What cases are these? “The red surface of an apple does not look like a matrix of molecules reflecting photons at certain critical wavelengths, but that is what it is,” Churchland says; “The sound of a flute does not sound like a sinusoidal compression wave train in the atmosphere, but that is what it is. [etc.]”

The problem with this response should be obvious, at least to someone with knowledge of the history of the mind-body problem and of modern philosophy generally. In particular, there is an obvious reason why the cases Churchland appeals to not only do not make the point he thinks they do, but in fact make the case for dualism even stronger. For the reason the identities in question – red with such-and-such a light wavelength, sound with a such-and-such a wave pattern, etc. – are plausible in the first place is that the early modern thinkers who inaugurated the “mechanical” conception of nature that informs modern science introduced a crucial distinction between features of the observable world that are observer-relative and those that are observer-independent – the famous primary quality/secondary quality distinction (spelled out in different ways by Galileo, Descartes, Locke, et al.). Colors, sounds, heat, cold, and the like as common sense understands them were relegated to the “observer-relative” side of the divide, and color, sound, heat, cold, etc. as objective, physical properties were, accordingly, redefined in terms of wave activity, the motions of particles, or some other “observer-independent” phenomena.

To see how this works in the case of one of Churchland’s examples, let’s distinguish between RED (in caps) and red (in italics) as follows:

RED: the qualitative character of the color sensations had by a normal observer when he looks at fire engines, “Stop” signs, Superman’s cape, etc. (which is different from the qualitative character of the sensations had by e.g. a color blind observer)

red: whatever physical property it is in fire engines, “Stop” signs, Superman’s cape, etc. that causes normal observers to have RED sensations

Now what seems to common sense to be very different from “a matrix of molecules reflecting photons at certain critical wavelengths” is RED. And sure enough, what science has shown to be identical to “a matrix of molecules reflecting photons at certain critical wavelengths” is only red, not RED. Indeed, part of the reason for distinguishing red and RED is precisely that RED seems clearly not to be identical to something like “a matrix of molecules reflecting photons at certain critical wavelengths,” since the “matrices of molecules” etc. are what they are regardless of who is looking at them while qualitative character is observer-relative.

Part of the problem with Churchland’s response to the argument from introspection, then, is that it commits a fallacy of equivocation: The sense of “red” in which “Red seems different from any property of a matrix of molecules etc.” (i.e. RED) is different from the sense of “red” in which “Science has shown that red really is just a property of a matrix of molecules etc.” (i.e. red). A similar fallacy is committed when he appeals instead to sounds or any other sensory qualities. Thus his examples do not show that our powers of observation have misled us in other domains, and thus should not be trusted in the case of introspection.

That’s one problem with his response. Another is that when we understand what is really going on in the history-of-science examples Churchland appeals to, we can see that they actually strengthen the case for dualism rather than undermine it. For if colors, sounds, heat, cold, etc. as common sense understands them – that is, in terms of their qualitative, phenomenal character – exist only in the mind of the observer and not in the physical world (which is comprised of nothing more than colorless, odorless, soundless, tasteless particles in motion, or whatever), then it seems clear that they cannot exist in the brain, or in any other physical object or system of physical objects, either. Hence they must be immaterial. As I have noted before, that was exactly the conclusion explicitly drawn by early modern thinkers like Cudworth and Malebranche – and at least implicitly by Descartes, Locke, and the other early modern advocates of the “mechanical philosophy” who also happened to be dualists – and by several philosophers since. Their view was that dualism, far from being a pre-scientific holdover destined to be abandon once we have sufficient knowledge of the brain, in fact follows from the very mechanistic conception of matter taken for granted in modern science. The basic problem was one of the themes of Thomas Nagel’s celebrated 1974 article “What is it like to be a bat?” (though Nagel is less committal there about precisely what philosophical conclusion we ought to draw from the problem). It was explicitly appealed to in defense of dualism in Richard Swinburne’s 1986 book The Evolution of the Soul.

Now Churchland or some other materialist might think there is a way to carve up the conceptual territory that doesn’t have such an implication. Fine and dandy, let’s hear it and evaluate it. But he oughtn’t to pretend that the “reductions” in question clearly favor materialism when in fact, historically, they were taken to favor the opposite view! And, especially, he oughtn’t to convey this false impression when purporting to offer an evenhanded presentation of the case for dualism.

Churchland’s treatment of the argument from irreducibility is equally bad. As evidence that our powers of reasoning can in fact be accounted for in materialistic terms, he appeals to the existence of electronic calculators. As evidence that language can be similarly accounted for, he appeals to the existence of “computer languages.” He fails even to mention the most glaringly obvious reply to such “explanations” – that they involve nothing more than a couple of bad puns, since so-called calculators don’t literally “calculate” and computers don’t literally possess “language.” Rather, both electronic calculators and computers generally are inherently devoid of any intentionality or powers of reasoning whatsoever, and have simply been designed by human beings – who do have genuine powers of reasoning and language – to carry out certain operations that aid us in our exercises in calculation and the like by simulating certain mental processes. To “explain” mental phenomena in terms of what computers do is thus precisely to get things back-asswards, since what computers do cannot be accounted for apart from the human minds which assign to their states and operations whatever meanings they have.

Again, the point isn’t that Churchland might not have a way to respond to such arguments. The point is that he pretends that the claims he makes easily and uncontroversially rebut the argument from irreducibility when in fact his claims are extremely controversial even among non-dualists. (John Searle and Hubert Dreyfus are only the two most prominent non-dualist philosophers to have criticized the suggestion that mental processes can be explained in terms of “computational” ones.) The hapless beginning student coming away from Churchland’s discussion would have no idea that his “Gee whiz, look what computers can do!” shtick is, by itself anyway, philosophically about as serious as “proving” that time travel is theoretically possible based only on what one saw once in a Star Trek episode.

Churchland also suggests that whatever explanatory difficulties materialism has are at least equally matched by any dualist attempt to explain mental phenomena in terms of “nonphysical mind-stuff.” Here again Churchland proves only that he doesn’t understand what the main arguments for dualism actually say. As I noted in my first post in this series, those arguments are not quasi-scientific “explanatory hypotheses” in the first place, but rather attempts at metaphysical demonstration. They do not “postulate” “mind-stuff” (whatever that is) any more than mathematicians “postulate” the existence of the number 48 as the “best explanation” of why 47 and 49 do not fall right next to each other in the series of natural numbers. If the arguments fail, they do not fail for the sorts of reasons that explanatory hypotheses fail (considerations of parsimony, lack of fit with existing empirical theory, etc.), any more than an attempted mathematical proof, when it fails, can fail for such reasons.

But that brings us to Churchland’s positive arguments against dualism, which we’ll look at in a third post.

25 comments:

  1. ED

    Would it be fair to say that Churchland's talk of 'red sensations' leadssto the 'represationalist' theory of reality advocated by Descarte and all the associated problems.
    Would it also be fair to say that in order to get back to sanity we must first demonstrate the validity of realist metaphysics, demonstrate the minds ability to dirctly know reality and proceed from there in order to get back to the external world?

    Happy St Stevens day
    Jack

    PS I'm enjoying the series on the mad natrulistst but I wondered if there is any chance of the scholastic bookshelf series of posts being revived?

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  2. Hi Jack,

    It doesn't necessarily entail representationalism, and the status of "secondary qualities" is in fact something Neo-Scholastic writers disagreed about (other than universally rejecting any suggestion that dealing with these qualities requires either a non-realist account of perception or a non-hylemorphic account of the material world).

    I do intend to return to the Scholastic's Bookshelf series, and soon. Sorry for the delay!

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  3. "The red surface of an apple does not look like a matrix of molecules reflecting photons at certain critical wavelengths, but that is what it is."

    I wonder how it is that Churchland knows that the red surface of an apple does not look like a matrix of molecules reflecting photons at certain critical wavelengths. If you ask me, that's precisely what it looks like.

    "The red surface of an apple does not look like a matrix of molecules reflecting photons at certain critical wavelengths, but that is what it is."
    Let's rephrase this:

    The red surface of an apple IS a matrix of molecules reflecting photons at certain critical wavelengths.

    Is this true?

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  4. Part of the problem with Churchland’s response to the argument from introspection, then, is that it commits a fallacy of equivocation: The sense of “red” in which “Red seems different from any property of a matrix of molecules etc.” (i.e. RED) is different from the sense of “red” in which “Science has shown that red really is just a property of a matrix of molecules etc.” (i.e. red). A similar fallacy is committed when he appeals instead to sounds or any other sensory qualities. Thus his examples do not show that our powers of observation have misled us in other domains, and thus should not be trusted in the case of introspection.


    I wonder. Is this the reason for why Churchland thinks we have no qualia, or is his denial of qualia responsible for this?

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  5. Scott,

    I wonder how it is that Churchland knows that the red surface of an apple does not look like a matrix of molecules reflecting photons at certain critical wavelengths. If you ask me, that's precisely what it looks like.

    Yes, I recall my undergrad phil of mind prof (who used Churchland's book) making the same point. In fairness to Churchland, though, I think he could say: "I'm just speaking with the vulgar here. The man on the street might say 'Red doesn't look like a bunch of molecules to me,' but that just means he hasn't thought carefully enough about what molecules behaving in such-and-such a way would in fact look like to someone with our visual apparatus etc."

    Is this true?

    Well, as I say, it depends on what one means by "red."

    Matthew,

    No, Churchland in fact sometimes tends more toward reductionism than eliminativism where qualia, specifically, are concerned. His eliminativist tendencies have to do instead with the propositional attitudes (beliefs, desires, etc.) (In general, different eliminative materialists are sometimes eliminativists about different aspects of the mind.)

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  6. "I do intend to return to the Scholastic's Bookshelf series, and soon. Sorry for the delay!"
    Hi Ed,

    Enjoyed TLS, started your volumes on Aquinas and Locke. You've engendered a hunger to learn more.

    I have Freddoso's translations of Franscisco Suarez on Efficient Causality. Do you know if his Disputations on the other 3 Arostotelian causes are available in English?

    Perhaps you could comment on his work in the future.

    Regards

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  8. Holy secondary qualities, Batman, this is a great series!

    Seriously, thanks for slicing and dicing Churchland. The one about how red doesn't look like a matrix of molecules is an absolute howler.

    I hope you'll let W4 readers know about these posts.

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  11. “The red surface of an apple does not look like a matrix of molecules reflecting photons at certain critical wavelengths, but that is what it is,” Churchland says; “The sound of a flute does not sound like a sinusoidal compression wave train in the atmosphere, but that is what it is. [etc.]”

    I do not at all mean to denegrate Mr Feser's response to Churchland, but rather to point to another fundamental flaw of his reasoning -- 'materialists' *always* (for they must) either ignore or obscure the truth that to say what a thing is made of is not to say what the thing is: a house is not simply a quantity of wood and nails, bricks and mortar; a human being is not simply a quantity of common (and cheap) chemicals.

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  12. I meant to say, "to say what a thing is made of is not [necessarily] to say what the thing is"

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  13. I am not sure why Churchland didn't point to such examples, but there is ample evidence in the psychological literature that people make numerous, huge mistakes in judging purely psychological matters (their beliefs about their own motivations, for example, are clearly contradicted by their patterns of behavior). That fact seems somewhat relevant to evaluating introspective evidence.

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  14. Hello Aaron,

    Yes, that would be a better consideration for Churchland to have appealed to. But of course, the relevance of such evidence to the specific question at hand is not obvious.

    Compare: Suppose someone has bad eyesight and consistently mistakes dogs for cats, distant cars for trucks, etc. We would naturally tend to doubt much of his testimony about whether such-and-such observable events really happened the way he says they did. But what we would not necessarily do is doubt that something happened that was at least very generally in the ballpark. In particular, we would not doubt that he has really experienced a world of physical objects existing independently of him, even if he isn't very good at telling us about some of the important details. And of course, there is also the fact that we know his testimony is bad only because we have better perceptual evidence to compare it to.

    Similarly, while the psychological evidence you allude to may indeed cast doubt on the reliability of certain aspects of certain kinds of introspective reports under certain conditions, it does not follow that it casts doubt on introspection as such, or that it shows that we are wrong about the general character (and not just the occasional detail) of the objects of introspection. But something like this more radical sort of conclusion would seem to be what Churchland would need in order to cast serious doubt on the argument from introspection.

    (BTW, I do not myself think the argument from introspection, at least in the simple form in which Churchland presents it, is a key argument for dualism or terribly probative. Or at least, I don't think it establishes the immateriality of things like qualia. But then, as an Aristotelian I have a very different understanding of "matter" than moderns do -- the argument may be stronger if one assumes a modern, mechanistic conception of matter.)

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  15. But do human persons *always* "make [] huge mistakes in judging purely psychological matters?" That is, after all, what Churchland's position entails.

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  16. And, assertions in "the literature" notwithstanding, is it really the case that human persons' "beliefs about their own motivations, for example, are clearly contradicted by their patterns of behavior," or is it that human persons frequently lie to themselves?

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  17. Hello Ilion,

    That is, after all, what Churchland's position entails.

    Yes indeed -- now if only he could come up with a coherent account of what a "mistake" is, consistent with eliminative materialism...!

    or is it that human persons frequently lie to themselves?

    Good point. If I say I believe P but act in a way that seems irrational given that I believe P, it doesn't follow that I don't really believe P -- I may just be irrational (either because I have contradictory beliefs, or refuse to see what follows from believing P, or whatever). Presumably the relevant psychological literature addresses this consideration, but it reinforces the point that a materialist would have to do more than cite that literature to cast serious doubt on the argument from introspection.

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  18. It would seem that people having the contradictory beliefs you describe, Ed, would already be reason to be suspicious of their introspective data; they're going wrong somewhere. Similarly, I'm not sure how it works when people lie to themselves, but it would seem that if they're ever successful, that again should make us suspicious of their introspective reports. This is of course all the sort of thing that Dennett talks about when he talks about heterophenomenology.

    Of course, I recognize that your central arguments depend on your Aristotelianism, not things like this introspection argument. Naturally, I further think that much of modern philosophy and science constitute an extended lesson in how important it is to free yourself from Aristotle's faulty assumptions. Just as you think naturalists don't really pay enough attention to the details of the Aristotelian position, it seems to me that you don't pay enough attention to the details of the criticisms of Aristotelianism to be found in Hume and Kant (and countless others, of course, but they're perhaps the biggest). I further suspect that well-motivated Humean and Kantian sentiments lie behind the attitudes of most modern naturalist philosophers, even if they (unsurprisingly) give much simpler arguments when they are called upon to, as they see it, beat the dead Aristotelian horse.

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  19. Aaron,

    Ed does discuss Hume, Kant and others in TLS. Certainly they come up often enough on this blog. I don't think it's correct to say that Ed's not paying attention to them or their criticisms of A-T. Maybe you think he's not properly presenting their positions, but if so I'm curious what you'd say were the key criticisms. As I understand Ed, his position is mostly that the important parts of Thomism, Aristotleanism, etc haven't even been argued against so much as ignored ("Formal and final causality is difficult, so let's stick with efficient causality and see how far we go") and then treated as refuted ("Well clearly formal and final causality are wrong, since we never talk about them").

    As for "introspective data", I think you're casting one hell of a broad net there. If the fact that Churchland and other naturalists are being woefully inconsistent is yet more proof that "introspection can go wrong", then apparently "introspection" covers everything. Logical arguments, philosophical arguments, how we interpret external world data like scientific data and empirical studies, etc. And at that point it seems what's being argued for isn't "naturalism" or "materialism" but across the board skepticism or, lacking that, acknowledgment of fideism (at least if we're going to be honest).

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  20. Hello Aaron,

    Well, it would be good to know exactly which details you think I'm ignoring. I would say that the standard Humean and Kantian moves in fact presuppose the falsity of classical philosophy, and particularly Aristotelian-Scholastic philosophy, rather than do anything to refute them. And as Crude points out, defending the Aristotelian position against Hume, Kant, et al. is a big part of what The Last Superstition is all about.

    In any event, it's not only the details the moderns ignore that are importnat. It's also -- and especially -- all the stuff they "know" about Aristotle, Aquinas, et al. that ain't so. Again, see TLS for details.

    I am of course aware that most contemporary academic analytic philosophers think Aristotelianism is a dead horse. I used to think so too. I was wrong. Or if I wasn't, merely reminding us of what most people think doesn't settle anything.

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  21. I was trying to suggest that a lot of what people think they know about the "standard Humean and Kantian moves" are gross oversimplifications of Hume and Kant. I do, however, further think rather more modern philosophers have learned the Humean and Kantian lessons than claim allegiance to Hume and Kant; many seem to think some more recent favored thinker has shown a new and better path when the more recent thinker has really only repeated a less well known part of Hume or Kant. But the path is indeed better, and that's what really matters.

    But it's true that things are more complicated than can be settled in a comments thread. I will add that philosophy which rejected Aristotle's assumptions has made impressive progress, and it is some kind of evidence against a claim that knowledge seems to advance when you make the assumption that it's false. Thus, I think even as you describe things (again, not that I concede your description is accurate), it would not be entirely fair to say that modern philosophy has merely presupposed that Aristotle was wrong.

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  22. Hello Aaron,

    I assume that by "advance" you mean the theoretical and technological successes of modern empirical science. But if so, then the problem with that is that it simply presupposes a modern conception of what counts as an "advance." Classical philosophy in general and Scholasticism in particular were not primarily interested in the first place in the prediction and control of nature for the sake of bettering our material condition, a la Bacon and Descartes. They regarded philosophy and science as properly concerned instead with ultimate causes and purposes. And the practical advantage of this was always understood, not in terms of new gadgets, improved hygiene and medicine, etc. but rather in terms of improvement of the soul. Hence the relative otherworldlness even of Plato and Aristotle, not to mention the medievals.

    What the moderns do is essentially to change the subject: Let's forget all that stuff and re-orient our efforts to improving the here and now. Quantitative methods will facilitate that, so let's re-define science in quantitative terms and ignore whatever doesn't fit that approach. This will allow us to become "masters and possessors of nature" and improve our lot in this world. The next life can take care of itself. Etc.

    Now this change of orientation may or may not be a good thing. But what it is not is in any way a refutation of the older view, which wasn't trying to do the same thing in the first place. The difference between classical/medieval thought and modern thought isn't primarily a difference in methods but a difference in ends. The trouble is that what started out as "Let's ignore those aspects of reality and focus instead on these ones" has gradually hardened into a dogmatic "Those purported aspects of reality don't really exist at all, only these ones do." And the "argument" for this is nothing more than a question-begging "If it doesn't fit our quantitative methods or further our this-worldly ends, it must not be real."

    Anyway, all of this is examined in detail in The Last Superstition.

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  23. Our Host: "I assume that by "advance" you mean the theoretical and technological successes of modern empirical science. But if so, then the problem with that is that it simply presupposes a modern conception of what counts as an "advance.""

    Unless one has an actual, and known, goal to which one is advancing -- unless one has an objective criterion (or set of criteria) against which to measure one's present state, and former states(s) -- then all words such as 'advance' and 'progress' are meaningless, denoting at most mere change of state. And in that case, any old change will do.

    The particular problem to which you're drawing attention here isn't so much in presupposition, per se -- all human endeavors make use of presuppositions, it cannot be otherwise for us -- but that the scientistic/positivistic presuppositions render human life/existence, and “progress,” meaningless.

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  24. "Anyway, all of this is examined in detail in The Last Superstition."

    And the summation you've given here is excellent!

    Might I suggest incorporating the content of this last post into the next edition of TLS? Kind of a "this is case of the modernist mind-set, and how it differs from the pre-modern, and the understanding which it is the purpose of this book to impart" statement.

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  25. "It would seem that people having the contradictory beliefs you describe, Ed, would already be reason to be suspicious of their introspective data; they're going wrong somewhere. Similarly, I'm not sure how it works when people lie to themselves, but it would seem that if they're ever successful, that again should make us suspicious of their introspective reports."

    And they figure all of this out by introspection, right?

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