Was Aquinas a materialist?

Denys Turner’s recent book Thomas Aquinas: A Portrait is beautifully written and consistently thought-provoking.  It is also a little mischievous, in a good-natured way.  A main theme of the book is what Turner characterizes as Aquinas’s “materialism.”  Turner is aware that Aquinas was not a materialist in the modern sense.  And as I have emphasized many times (such as at the beginning of the chapter on Aquinas’s philosophical psychology in Aquinas), you cannot understand Aquinas’s position unless you understand how badly suited the standard jargon in contemporary philosophy of mind is to describe that position.  Turner’s reference to Aquinas’s “materialism” is intended to emphasize the respects in which Aquinas’s position is deeply at odds with what many think of as essential to a “dualist” conception of human nature.  And he is right to emphasize that.  All the same, as I have argued before, if we are going to use modern terminology to characterize Aquinas’s view -- and in particular, if we want to make it clear where Aquinas stood on the issue that contemporary dualists and materialists themselves think is most crucially at stake in the debate between dualism and materialism -- then “dualist” is a more apt label than “materialist.”

Chomsky on the mind-body problem

I am, to say the very least, not a fan of Noam Chomsky’s writings on politics and foreign policy. But his straightforwardly philosophical work is always interesting and important even when one disagrees with it. A case in point is his view of the traditional mind-body problem. The usual assumption is that we have a clear understanding of what matter is, and that the difficulty has to do with explaining how thoughts, sensations, and other mental phenomena relate to material processes in the nervous system. Are the former identical to or supervenient upon the latter? Various anti-materialist arguments purport to show that they cannot be either, which seems to entail some form of dualism. But in that case we face the interaction problem. In any event, the “body” side of the mind-body problem is usually taken to be unproblematic; it is mind that raises the puzzles, or so it is thought.

Chomsky rejects this assumption. In his view, “body” is as problematic as mind; so much so that we do not even have a clear idea of what the mind-body problem is. As he writes in Language and Problems of Knowledge: The Managua Lectures:

The mind-body problem can be posed sensibly only insofar as we have a definite conception of body. If we have no such definite and fixed conception, we cannot ask whether some phenomena fall beyond its range. The Cartesians offered a fairly definite conception of body in terms of their contact mechanics, which in many respects reflects commonsense understanding. Therefore they could sensibly formulate the mind-body problem… (p. 142)

[However] the Cartesian concept of body was refuted by seventeenth-century physics, particularly in the work of Isaac Newton, which laid the foundations for modern science. Newton demonstrated that the motions of the heavenly bodies could not be explained by the principles of Descartes’s contact mechanics, so that the Cartesian concept of body must be abandoned. (p. 143)

In other words, when we think of causation in the natural world as Descartes did – that is, as involving literal contact between two extended substances – then the way in which a thought or a sensation relate to a material object becomes mysterious. Certainly it cannot be right to think of a thought or sensation as making literal physical contact with the surface of the brain, or in any other way communicating motion in a “push-pull” way. But when we give up this crude model of causation, as Newton did, the source of the mystery disappears. At the same time, no systematic positive account of what matter as such is has ever really been put forward to replace Descartes’ conception. Hence, Chomsky continues:

There is no longer any definite conception of body. Rather, the material world is whatever we discover it to be, with whatever properties it must be assumed to have for the purposes of explanatory theory. Any intelligible theory that offers genuine explanations and that can be assimilated to the core notions of physics becomes part of the theory of the material world, part of our account of body. If we have such a theory in some domain, we seek to assimilate it to the core notions of physics, perhaps modifying these notions as we carry out this enterprise. (p. 144)

That is to say, we have in Chomsky’s view various worked-out, successful theories of different parts of the natural world, and we try to integrate these by assimilating them to “the core notions of physics,” but may end up altering those core notions if we need to in order to make the assimilation work. As a result, as Chomsky once put it to John Searle, “as soon as we come to understand anything, we call it ‘physical’” (quoted by Searle in The Rediscovery of the Mind, p. 25). But we have no conception of what is “physical” or “material” prior to and independently of this enterprise. And since the enterprise is not complete, “physical” and “material” have no fixed and determinate content; we simply apply them to whatever it is we happen at the moment to think we know how assimilate into the body of existing scientific theory. As a consequence:

The mind-body problem can therefore not even be formulated. The problem cannot be solved, because there is no clear way to state it. Unless someone proposes a definite concept of body, we cannot ask whether some phenomena exceed its bounds. (Language and Problems of Knowledge, p. 145)

Hence, while Chomsky is no dualist, neither does he embrace the standard alternatives: “There seems to be no coherent doctrine of materialism and metaphysical naturalism, no issue of eliminativism, no mind-body problem” (New Horizons in the Study of Language and Mind, p. 91). In short, if the problem has no clear content, neither do any of the solutions to it. Chomsky’s preferred approach, it seems, is just to carry on the task of developing and evaluating theories of various aspects of the mind and integrating them as one can into the existing body of scientific knowledge, letting the chips fall where they may vis-à-vis the definition of “physical” or “material.”

What should we make of this? Chomsky is, I think, absolutely right to emphasize that the concept of matter is no less problematic than that of mind, and that this entails that “materialism” and “physicalism” are far less determinate in content than their adherents typically suppose. (This is something Bertrand Russell also emphasized, as do later philosophers of mind influenced by him, such as Grover Maxwell, Michael Lockwood, Galen Strawson, and David Chalmers.) At the same time, I think it is clear that the concept of the “physical” or the “material” is not in fact as elastic as Chomsky’s remarks might imply, either in the thinking of most scientists or in that of philosophical naturalists.

It is true that the positive content of the notion is fairly indeterminate, subject to fluctuation with every change in the physical sciences. But there is a core of negative content that is more or less fixed. That is to say, whatever matter turns out to be, there are certain features that modern philosophers, and scientists in their philosophical moments, tend to refuse ever to attribute to it.

For at least some of them, this would seem to include sensory qualities like color, odor, taste, sound, and the like as common sense understands them. For the mechanistic revolution Chomsky alludes to was not merely, and indeed not even essentially, committed to the idea that material causation involves literal contact. It was also and more lastingly committed to some variant or other of a “primary/secondary” quality distinction on which there is nothing in the material world that “resembles” our “ideas” of the sensory qualities mentioned (as Locke would put it). If we want to redefine the “red” of a fire engine in terms of how its surface reflects photons at certain wavelengths, we can say that the fire engine is red. But if by “red” we mean the way red “looks” to us when we perceive it, then nothing like that exists in the fire engine, which is (if we think of color in these commonsense terms) intrinsically “colorless.” And so on for sounds, tastes, and all the rest. Color, odor, taste, sound, and the like – again, as common sense understands them (rather than as redefined for purposes of physics) – are reinterpreted by mechanism as projections of the mind, existing only in consciousness. This is the origin of the “qualia problem,” and the puzzle now becomes how to relate these “qualia” or “phenomenal properties” to the intrinsically colorless, odorless, tasteless particles that make up the brain just as much as they do external material objects.

Now if one insists on denying these sensory qualities to matter, then it seems clear that we do have a clear enough conception of “body” to generate a mind-body problem. More than that, we have a conception that clearly implies that the mind (in which alone these qualities exist) cannot be something material or bodily – that, at any rate, is the lesson drawn by early modern thinkers like Cudworth and Malebranche, and by contemporary writers like Richard Swinburne, who take the “mechanistic” conception of matter itself to entail dualism. (I have discussed this issue before in several places, e.g. here, here, and in The Last Superstition.)

A naturalist could, however, decide to reincorporate the sensory qualities into the material world by conceiving of them as the intrinsic properties of matter, which “flesh out” the abstract mathematical structure described by physics. And this is precisely the move made by the writers influenced by Russell whom I mentioned above – Maxwell, Lockwood, Strawson, and Chalmers. To be sure, the resulting position is hardly “materialist” or “physicalist” as those terms are usually understood; some of these writers describe it instead as neutral monist, or panpsychist, or even as a variety of dualism. But they also tend to regard it as nevertheless consistent with a kind of naturalism, even if what is allowed to count as “natural” is thereby expanded considerably. (An exchange between Strawson and Chomsky can be found in Louise Antony and Norbert Hornstein, eds., Chomsky and His Critics.)

There is, however, another, more fundamental and indeed absolutely “non-negotiable” component of the mechanistic picture of the world inherited from the early modern philosophers, one well-known to regular readers of this blog: the rejection of Aristotelian formal and final causes. As I have argued in many places (such as in this recent post, as well as in The Last Superstition and Aquinas), this is the surviving and definitive element of the mechanistic revolution, and the one which naturalists seem to take, either explicitly or implicitly, to be crucial to their position. Whatever else the physical world may turn out to be like, and whatever alterations might be made to scientific practice, the mechanist, and the naturalist, are committed to the view that there is no such thing as goal-directedness or teleology intrinsic to the natural world, and that proper scientific procedure ought never to posit such immanent teleology. (See the quotes in the post just linked to for examples of philosophers who endorse this conception of science.)

If this is correct, then we once again have a conception of matter, albeit a negative one, which is determinate enough to generate a mind-body problem. If nothing in the material world inherently points beyond itself as to an end or final cause, then it is hard to see how that aspect of the mind philosophers call intentionality – the way that a thought “points to,” is “about,” or is “directed at” something beyond itself (such as the way your thought about the Eiffel tower is “about” or “directed at” the Eiffel tower) – can possibly be given a “naturalistic” explanation. As I have argued in several places (e.g. here) a dualism of intentional phenomena and material phenomena seems unavoidable given a mechanistic conception of nature, even if the Russellian naturalist can avoid a dualism of qualitative phenomena and material phenomena by expanding his conception of the “natural” (though even that is not a sure thing).

As Jerry Fodor puts it in Psychosemantics: The Problem of Meaning in the Philosophy of Mind:

I suppose that sooner or later the physicists will complete the catalog they’ve been compiling of the ultimate and irreducible properties of things. When they do, the likes of spin, charm, and charge will perhaps appear on their list. But aboutness surely won’t; intentionality simply doesn’t go that deep. It’s hard to see, in face of this consideration, how one can be a Realist about intentionality without also being, to some extent or other, a Reductionist. If the semantic and the intentional are real properties of things, it must be in virtue of their identity with (or maybe of their supervenience on?) properties that are themselves neither intentional nor semantic. If aboutness is real, it must be really something else. (p. 97)

Of course, Fodor’s “Reductionism” is not really the only option. One could combine Realism about intentionality with dualism instead; or with idealism; or with Aristotelian hylemorphism. But the last of these positions would indeed be ruled out if one agrees with Fodor about what the physicists’ ultimate catalog must look like, and the other two options would certainly be incompatible with at least most naturalists’ understanding of “naturalism.” In any event, the passage illustrates the point that contemporary philosophers do have a determinate enough conception of matter (albeit a negative one) to generate a mind-body problem: Fodor’s point is that given the conception of the physical to which he and like-minded philosophers are committed, intentionality becomes philosophically problematic. The passage illustrates also that the naturalist seems bound at the end of the day to deny the existence of intentionality given his conception of matter. For to say that “if aboutness is real, it must be really something else” is just a cute way of saying that aboutness is not real, and must be replaced in our ontology by some physicalistically “respectable” ersatz. As Searle has complained (e.g. in the book cited above), materialist “reductions” of this or that mental phenomenon never really succeed in “reducing” it at all, but either change the subject or implicitly deny the existence of the phenomenon. Reductionist versions of materialism are really just disguised forms of eliminative materialism.

That is a big topic, but suffice it for now to emphasize two points. First, while Chomsky is right to say that modern philosophers’ conception of “matter” or “the physical” is far less determinate than they often suppose, it is in fact determinate enough to generate a real mind-body problem. Second, the mechanistic assumptions underlying this determination of their conception of matter are, contrary to what they (and Chomsky himself, I imagine) typically suppose, not “scientific” at all, but purely philosophical – and (as my regular readers know) in my view deeply mistaken.

Scientism roundup

In several recent posts we have dealt at least indirectly with scientism, the view that the only real knowledge is scientific knowledge.  Scientism is an illusion, a bizarre fantasy that makes of science something it can never be.  Seemingly the paradigm of rationality, it is in fact incoherent, incapable in principle of being defended in a way consistent with its own epistemological scruples.  It should go without saying that this in no way entails any criticism of science itself.  For a man to acknowledge that there are many beautiful women in the world does not entail that he doesn’t think his own wife or girlfriend is beautiful.  Similarly, to say that there are entirely rational and objective sources of knowledge other than science does not commit one to denying that science is a source of knowledge.  Those who cannot see this are doubly deluded – like a vain and paranoid wife or girlfriend who thinks all women are far less attractive than she is and regards any suggestion to the contrary as a denial of her own beauty.  Worse, like an already beautiful woman whose vanity leads her to destroy her beauty in the attempt to enhance it through plastic surgery, scientism threatens to distort and corrupt science precisely by exaggerating its significance.

Gelernter on computationalism

People have asked me to comment on David Gelernter’s essay on minds and computers in the January issue of Commentary.  It’s written with Gelernter’s characteristic brio and clarity, and naturally I agree with the overall thrust of it.  But it seems to me that Gelernter does not quite get to the heart of the problem with the computer model of the mind.  What he identifies, I would argue, are rather symptoms of the deeper problems.  Those deeper problems are three, and longtime readers of this blog will recognize them.  The first two have more to do with the computationalist’s notion of matter than with his conception of mind.

Conceiving and hallucinating

The “conceivability argument” for dualism holds that (1) it is conceivable that I might exist apart from by body, and therefore that (2) it is metaphysically possible for me to exist apart from my body, so that (3) I am not identical to my body. I put forward a detailed and sympathetic exposition of this argument in chapter 2 of Philosophy of Mind – for it is more interesting and defensible than some philosophers give it credit for – but I do not in fact endorse it. It is essentially a variation on Descartes’ “clear and distinct perception” argument for dualism, and as I’ve argued elsewhere, what’s true in that argument isn’t new and what’s new isn’t true. (As an Aristotelico-Thomist I reject the rationalist assumptions inherent in Descartes’ version, and the Kripke-style modal assumptions inherent in modern versions. But demonstrating the mind’s immateriality does not require committing oneself to these assumptions.)

But as I say, the argument is more defensible than it is often given credit for. Take the thought experiment I discussed in Philosophy of Mind, W. D. Hart’s “seeing without a body” example. (Hart develops this example in his book The Engines of the Soul and in his article “Dualism” in Samuel Guttenplan, ed., A Companion to the Philosophy of Mind. Follow the links and you can read the relevant sections online via Google books.) Hart asks you to imagine that you wake up one morning, look in the bathroom mirror, and see staring back at you two empty eye sockets where your eyeballs used to be. This is no doubt physically impossible, but it does seem that we can at least conceive of having such an experience. There is no apparent contradiction or incoherence in the idea. Seeing without eyeballs is thus arguably metaphysically possible even if it is not physically possible.

Hart then asks us to extend the thought experiment in various ways. For example (and as I suggested extending it in the book) you might imagine that instead of seeing two empty eye sockets staring back at you, what you see in the mirror is the stump of your neck where your head used to be – a headless body, arms raised in horror. Seeing without a head, and thus without a brain, seems perfectly conceivable, then, and therefore (by the reasoning of the conceivability argument) at least metaphysically possible even if not physically possible. And if that is conceivable, so too is it conceivable to have the experience of seeing without arms, legs, torso, or any body at all; in which case (the argument claims) it is metaphysically possible to see without a body. But since seeing is a kind of mental state, it is therefore metaphysically possible to have a mind without a body.

Now, to evaluate the conceivability argument, we have to determine (a) whether what seems to be conceivable in this case really is conceivable, (b) whether conceivability really does entail metaphysical possibility, and (c) whether the metaphysical possibility of A existing without B really does entail that A and B are non-identical. I commend Hart’s discussion of these various issues (and also my discussion in Philosophy of Mind) to the interested reader. What I want to focus on here is just (a), and in particular on one possible challenge to (a).

A friend of mine sometimes reads this blog at work. (“I’m that bored,” he explains.) He’s been reading Philosophy of Mind, and when I saw him the other day he asked vis-à-vis the Hart example: “What does that prove? Isn’t it just obvious that I would be hallucinating?” That’s a fair question. We might put the objection this way: For the conceivability argument to work, we have to be able to show that (among other things) it really is conceivable to see without a body. But Hart’s example shows at most only that it is conceivable that we might have an experience that seems like the experience of seeing without a body. And that’s not good enough, because such an experience might be hallucinatory. “Seems like” does not entail “really is.” Therefore, “We can conceive of it seeming like such-and-such is the case” does not entail “We can conceive of such-and-such really being the case.”

But I think the objection fails. The reason is that hallucination seems parasitic on veridical experience in a way that ensures that if we can conceive of hallucinating something, it follows that we can conceive of really experiencing it. Consider that it isn’t just impossible to conceive of seeing a round square. It is also impossible to conceive of hallucinating a round square. And this is so, surely, precisely because it is impossible to conceive of seeing one. Hallucinating (or visually hallucinating, anyway) is just a kind of defective seeing. So, what’s impossible for seeing in general is impossible for hallucinations in particular. But then, if it were impossible for us to see without a body, it would also be impossible for us to hallucinate seeing without a body. So, since the Hart example at least shows (by the objector’s own admission) that the latter is possible, that suffices to show that the former is possible as well.

Or so it seems to me. The conceivability argument may or may not fail on other grounds, but I think that at least to this extent it is on solid ground.

Warby on Philosophy of Mind

Over at the online edition of Australia's Quadrant magazine, Michael Warby kindly reviews my book Philosophy of Mind. As Warby notes, the book is now out in a revised edition. (The first edition has the subtitle "A Short Introduction" and a surrealist cover illustration. The new edition, pictured at left, has a "brain in a vat" cover with the new subtitle "A Beginner's Guide." The only difference in content is the addition of an eight-page Postscript to the new edition.)

You can find a sample chapter here. Like the book in general (which first appeared in 2005), it is perhaps a tad too Cartesian and "representationalist" in spirit. Were I writing it today, I would make it more thoroughly Aristotelian-Thomist. (The philosophy of mind related portions of The Last Superstition reflect my transition toward a more consistent Thomism.) Still, Cartesianism is better than materialism, to say the very least.

Anyway, for interested readers, here is the complete table of contents:

Preface and acknowledgments

1. Perception

Dreams, demons, and brains in vats
Indirect realism
Skepticism
Appearance and reality, mind and matter
Further reading

2. Dualism

Minds and brains, apples and oranges
The indivisibility argument
The conceivability argument
The interaction problem
Further reading

3. Materialism

Tables, chairs, rocks, and trees
Reduction and supervenience
Cause and effect
Behaviorism
The identity theory
Functionalism
The burden of proof
Further reading

4. Qualia

The inverted spectrum
The “Chinese nation” argument
The zombie argument
The knowledge argument
Subjectivity
Property dualism
Further reading

5. Consciousness

Eliminativism
Representationalism and Higher-Order Theories
Russellian identity theory and neutral monism
Troubles with Russellianism
A more consistent Russellianism
Consciousness, intentionality, and subjectivity
The binding problem
Further reading

6. Thought

Reasons and causes
The computational/representational theory of thought
The argument from reason
The Chinese Room argument
The mind-dependence of computation
Thought and consciousness
Further reading

7. Intentionality

Naturalistic theories of meaning
1. Conceptual role theories
2. Causal theories
3. Biological theories
4. Instrumentalist theories
Eliminativism again
The indeterminacy of the physical
1. Representations
2. Concepts
3. Formal reasoning
Materialism, meaning, and metaphysics
Further reading

8. Persons

Personal identity
Consequences of mechanism
Hylomorphism
Thomistic dualism
Philosophy of mind and the rest of philosophy
Further reading

Postscript (2006)

Glossary

The materialist shell game

Materialists sometimes argue that the mind is bound to succumb to naturalistic explanation, because everything else has. How could it be the only hold-out? As I have argued in several places (most recently and at greatest length in The Last Superstition), far from being the knock-out blow some materialists think it, this argument actually shows how very shallow and historically ill-informed much materialist thinking is. For, whether explicitly or implicitly, materialism is committed to the mechanistic conception of matter inherited from early modern thinkers like Galileo, Descartes, Hobbes, Boyle, and Locke, where the core of this conception – or the only part of it that has survived over the centuries, anyway – is the idea that neither goal-directedness or final causality, nor sensory qualities like color, odor, taste, sound, and the like as we experience them, exist in the objective material world, but only in the mind of the perceiver. Matter, that is to say, was simply defined in such a way that (a) mental properties were taken to be paradigmatically non-material, and (b) certain features that common sense and the Scholastic tradition regarded as inherent to matter were re-defined as mental. This both facilitated the giving of “naturalistic explanations” – since whatever wouldn’t fit the naturalistic-cum- mechanistic explanatory model was simply defined away as a mere mental projection in the first place, not part of the material world at all – but also guaranteed that the mind would be uniquely resistant to the same sort of explanatory procedure. For the mind was made the rug under which everything that wouldn’t fit the naturalistic model could be swept. By definition, as it were, the same “sweeping” strategy cannot possibly be applied to the mind itself.

Victor Reppert kindly draws his readers’ attention to a passage in my book Philosophy of Mind where I made this point. But it is hardly original with me. Reppert also cites a passage from Richard Swinburne’s The Evolution of the Soul which makes the same point. Thomas Nagel’s famous article “What is it like to be a bat?” makes it too. (Most readers of this article wrongly focus on the bat example itself, quibbling over whether analogies with human experience coupled with neuroscientific knowledge might allow us to infer what it is like to be one. But in doing so they miss Nagel’s deeper and more devastating point that it is the “objectivist” way in which contemporary philosophers tend to conceive of matter that makes a naturalistic explanation of mind – not just the conscious experiences of bats, but any “subjective” conscious mental state – impossible in principle.)

Indeed, the point is as old as modern philosophy itself. It was central to the thinking of the Cambridge Platonist Ralph Cudworth (1617-1689) and the Cartesian Nicolas Malebranche (1638-1715), both of whom emphasized that the “mechanical philosophy” necessarily entails dualism. It is also at least implicit in Descartes and Locke. If you are going to insist that matter is comprised only of colorless, odorless, tasteless, soundless particles devoid of any inherent meaning or goal-directedness, then of course qualia and intentionality are going to have to count as immaterial, and color, odor, taste, sound, etc. understood as objective features of nature would simply have to be re-defined (in terms of patterns of motion in particles, or whatever). Hence the reason so few modern philosophers, until very recently, followed Hobbes in his materialism, is not because they were afraid to follow out the implications of modern science, but rather precisely because they did follow out its implications (that is, insofar as modern science tends to take a “mechanical” conception of matter for granted). And the reason so many recent philosophers have followed Hobbes is, I would suggest, that they have forgotten the history of their subject and not thought carefully about the conception of matter they are implicitly committed to. When a contemporary philosopher of mind with naturalistic sympathies does think carefully about this conception, he tends either to come to doubt that naturalistic models of the mind really can succeed (as e.g. Fodor, McGinn, and Levine do in their various ways), or to suggest that it is only by developing some radically new conception of matter that naturalism can be defended (as e.g. Nagel and Galen Strawson do in different ways), or to adopt some “naturalistic” form of dualism (as e.g. Chalmers does explicitly and Searle does implicitly, despite his best efforts to avoid it.)

The upshot is that the materialist’s “everything else has been explained naturalistically” shtick is little more than a shell game. “Everything else” is “explained” only by hiding the recalcitrant features, like a pea, under the shell of the mind. The illusion only works precisely because there is a shell to hide things under, and thus requires dualism. To assume otherwise is like assuming that a shell game scam could successfully be carried out either by hiding, not only the peas, but also every shell under a shell (as reductionist forms of materialism effectively do insofar as they assume that the same strategy applied to explaining heat, color, sound, etc. – that is, carving off and “hiding” the subjective element and re-defining the phenomenon in mechanistic terms – can be applied to mental states themselves) or by getting rid of the shells entirely (as eliminative materialism effectively does). Not even the boldest sidewalk scammer would attempt such folly. For that you need an intellectual in the grip of a theory.

Reading Rosenberg, Part VIII

And now, dear reader, our critical look at Alex Rosenberg’s The Atheist’s Guide to Reality brings us to the pseudoscience du jour.  Wittgenstein famously said that “in psychology there are experimental methods and conceptual confusion” (Philosophical Investigations, II, xiv, p. 232).  He might as well have been talking about contemporary neuroscience -- or, more precisely, about how neuroscience becomes distorted in the hands of those rich in empirical data but poor in philosophical understanding.  Every week seems to bring some new sensationalistic claim to the effect that neuroscience has “shown” this or that -- that free will is an illusion, or that mindreading is possible, or that consciousness plays no role in human action -- supported by arguments notable only for the crudeness of the fallacies they commit.  

Tyler Burge has given the label “neurobabble” to this modern intellectual pathology, and Raymond Tallis calls it “neurotrash,” born of “neuromania.”  I’ve had reason to comment on it in earlier posts (here and here) and an extreme manifestation of the disease is criticized in the last chapter of The Last Superstition.  M. R. Bennett and P. M. S. Hacker subject neurobabble to detailed and devastating criticism in their book Philosophical Foundations of Neuroscience, and Tallis does a bit of housecleaning of his own in Aping Mankind.  Neurobabble is a key ingredient in Rosenberg’s scientism.  Like so many other contemporary secularists, he has got the brain absolutely on the brain, and maintains that modern neuroscience vindicates some of his more outrageous metaphysical claims.  In particular, he thinks that so-called “blindsight” phenomena establish that consciousness is irrelevant to our actions, and that neuroscientist Benjamin Libet’s experiments cast doubt on free will.  (Jerry Coyne, in a recent article, has made similar claims about free will.  What I’ll say about Rosenberg applies to Coyne as well.)

Popper’s World 3

The Self and Its Brain: An Argument for Interactionism, a long exchange between philosopher Karl Popper and neuroscientist John Eccles, is among the most significant 20th century defenses of mind-body dualism. I do not agree with every aspect of their approach, but the book is filled with interesting things and deserves more attention than it has received in contemporary philosophy of mind.

Popper famously distinguished between three “worlds” or levels of reality. (Though whether “levels” of reality is the right gloss on Popper’s theory is not clear. “Kinds”? “Aspects”?) World 1 is the world of physical entities and states – tables, chairs, rocks, trees, fundamental particles and forces, human bodies and behavior, and so forth. World 2 is the world of thoughts, sensations, and mental phenomena in general. World 3 is the world of scientific and philosophical theories, arguments, stories, social institutions, works of art and the like. World 3 differs from World 1 in that the entities comprising it are abstract; for example, though a theory or argument might be embodied in a particular book (a World 1 object) it does not depend for its reality on the existence of that book, or on any book or World 1 object at all. We could still consider the Pythagorean theorem, know it to be true, prove it, etc. even if every geometry textbook that had ever existed were destroyed. World 3 differs from World 2 in being objective or public, whereas World 2 is subjective or private. Your thoughts and experiences are directly knowable only to you, but World 3 objects are equally accessible to everyone.

The objectivity or “autonomy” of such World 3 objects as theories and arguments is especially evident in Popper’s view from the fact that they have logical relations – and in particular, unforeseen implications and unnoticed inconsistencies – that may not be noticed until well after we first consider them, but which were evidently there all the time waiting to be discovered. Naturally, he takes mathematics to illustrate the point vividly, but it is in his view no less evident from empirical scientific theories. The clearest mark of the reality of all three worlds is in Popper’s judgment the fact that World 3 has a causal influence on World 1, and does so only via World 2. For example, the scientific theories which entailed the possibility of nuclear weapons have had an obvious impact on the material world – they have resulted in various nuclear tests, in the destruction of Hiroshima and Nagasaki, and so forth – but only because scientists carried out the mental activity of working out the implications of the theories and applying them.

Popper’s World 3 is often compared to Plato’s realm of the Forms, and Popper himself acknowledges that there are similarities. But he also emphasizes the significant differences between his view and Plato’s, not the least of which is that he takes World 3, despite its objectivity or autonomy, to be something “man-made,” its objects in the strict sense being what the human mind “abstracts” from their World 1 embodiment. Though Popper does not take note of the fact or develop the theme in much detail, this is clearly reminiscent of an Aristotelian or “moderate realist” approach to the traditional problem of universals, as distinct from the “extreme realism” of Platonism. (See here and here for a useful short account of the traditional Aristotelian-Thomistic-Scholastic approach to the issue and its significance.)

In other ways too Popper’s views as expressed in The Self and Its Brain overlap to some extent with Aristotelian ones. The emphasis on abstract thought – and thus on what is unique to human beings – as what is of greatest interest in the debate over dualism is very much in line with the classical Platonic-Aristotelian-Scholastic approach to this subject, which is quite different from the contemporary obsession with “qualia” and the like. There is also Popper’s acknowledgement of the reality of “downward causation” in physical systems and his consequent rejection of physicalistic reductionism even where non-mental phenomena are concerned. And there is his affirmation of the existence of objective “propensities” in nature, which (possibly) hints at something like the Aristotelian notion of potencies. (Though these last two themes take us beyond the World 3 thesis itself.)

On the other hand, there are some decidedly un-Aristotelian themes in Popper as well. There is, for instance, his denial of substance in favor of a “process” conception of the material world; and there is his rejection of essentialism, which he seems to assume is inherently Platonistic and committed to an a priori or “armchair” methodology. (This is a serious misunderstanding, and a very common one, which we Aristotelian-Thomistic (A-T) types find it rather tiresome constantly to have to rebut. See Oderberg’s Real Essentialism for the most thorough rebuttal, and pp. 30-38 for a reply to Popper specifically.)

All the same, any Aristotelian must admire the non-ideological character of Popper’s approach to the mind-body problem. Unlike so many contemporary philosophers of mind, he does not fatuously pretend that a presumption in favor of materialism has somehow been established by modern science, or that dualism rests on “intuitions” or the like. He does not present the problem situation as if it were a matter of determining whether we ought to wedge the evidence of our ordinary experience into the Procrustean bed of naturalism or instead to lop it off entirely – as if these were the only alternatives worth taking seriously. Nor does he have any theological ax to grind; he deliberately avoids getting into the question of the soul’s immortality (and even expresses the view that he would prefer not to be immortal). He merely observes that reality clearly comprises at least the three sorts of thing in question and that any serious solution to the mind-body problem will simply have to accommodate this plain fact. As The Self and Its Brain shows, Popper is also much better informed about the actual history of the mind-body problem than contemporary naturalists tend to be. (As my series of posts on Paul Churchland indicated, many naturalists seem unfamiliar with anything other than the crudest caricatures of what non-naturalist philosophers of mind have actually said.)

In short, at least where the mind-body problem is concerned, Popper does not attack straw men and he respects Butler’s famous dictum that “Everything is what it is, and not another thing.” (I put to one side for present purposes Popper’s views in political philosophy and philosophy of science, contexts in which he is more open to criticism on these grounds.) He thereby stands acquitted of a charge John Searle raised in The Rediscovery of the Mind against his fellow contemporary philosophers of mind:

[W]e let our research methods dictate the subject matter, rather than the converse. Like the drunk who loses his car keys in the dark bushes but looks for them under the streetlight, "because the light is better here,” we try to find out how humans might resemble our computational models rather than trying to figure out how the conscious human mind actually works…

[W]e ought to stop saying things that are obviously false. The serious acceptance of this maxim might revolutionize the study of the mind. (p. 247)

Like Searle, Popper is in my estimation better as a critic than as a positive theorist. (I discussed an important anti-materialist argument of his in an earlier post.) Still, from an A-T point of view even his positive theorizing is closer to the mark than that of most other contemporary dualists.

When Frank jilted Mary

We had reason recently to allude to Frank Jackson’s famous “knowledge argument” against physicalism. You’ll recall that the argument goes like this: Physicalism claims that if you know all the physical facts that there are to know about people, then you know all the facts there are to know about them, period; for human beings are (says the physicalist) entirely physical. But now consider Mary, a master neuroscientist of the future. Mary has lived her entire life in a black and white room, and has never had any experiences of colors. Still, having studied all the relevant neuroscientific literature, she knows everything there is to know about the physics and physiology of color perception. Hence she knows, for example, everything there is to know about what goes on in someone’s brain when he sees a red object, everything there is to know about the surface reflectance properties of red objects, and so forth. Now imagine that she leaves her black and white room and sees a red object herself for the first time. Does she learn something new? Surely she does – she learns what it’s like to see red. But then, physicalism is false. For though Mary knew all the physical facts about human perceptual experience before she left the room, she didn’t know all the facts, since she learned something when she left the room. Hence there are facts about human nature, and in particular facts about conscious experience, that escape the physicalist story – namely facts about “qualia,” the subjective features of a conscious experience in virtue of which there is “something it is like” to have that experience.

Jackson first presented this argument is his 1982 paper “Epiphenomenal Qualia,” and repeated it in 1986 in “What Mary Didn’t Know.” (There were several precursors to the argument, such as Thomas Nagel’s “What is it like to be a bat?”, and similar but independently developed ideas, such as Howard Robinson’s deaf scientist example in his 1982 book Matter and Sense.) The argument has generated an enormous literature. Some of it is collected in the Ludlow, Nagasawa, and Stoljar edited volume There’s Something About Mary: Essays on Phenomenal Consciousness and Frank Jackson’s Knowledge Argument. You will find there also some later essays by Jackson in which he expresses second thoughts about the argument; for by the late 1990s he had recanted and embraced physicalism.

Why? For no good reason, in my view; nor in the view of Jackson’s fellow “knowledge argument” proponent Howard Robinson, whose (characteristically excellent) essay “Why Frank Should Not Have Jilted Mary” offers a penetrating critique of Jackson’s current views. (You can read part of Robinson’s article here, though the anthology in which it appeared – Edmond Wright’s The Case for Qualia – is well worth the purchase price.)

As Stoljar and Nagasawa note in their introduction to There’s Something About Mary, “the argument, [the later Jackson] said, contained no obvious fallacy, and yet its conclusion – that physicalism is false – must be mistaken” (p. 23). Again, why? We might distinguish two components of Jackson’s current position. First, there is Jackson’s justification for claiming that something or other must be wrong with the knowledge argument, even if it seems to be perfectly cogent; and second, there is his strategy for explaining away the apparent cogency of the argument by suggesting where a fallacy is most likely to be found in it. The second component involves appeal to a “representationalist” theory of consciousness, and interested readers will find in Robinson’s essay a useful discussion of the problems with Jackson’s application of this theory. (For my money the main problems are two: First, representationalism is, at the end of the day, merely a riff on functionalism, and thus cannot serve to rebut the knowledge argument any more than – by Jackson’s own lights pre-recantation – older versions of functionalism could. Second, the key notion of “representation” itself cannot be accounted for in physicalist terms, so that even a successful representationalist analysis of consciousness could not vindicate physicalism.)

But it is the first component of Jackson’s current position – and some remarks of Robinson’s that are relevant to it – that I want to focus on here. In his 2002 essay “Mind and Illusion” (available in the Ludlow, Nagasawa, and Stoljar volume), Jackson tells us that:

Much of the contemporary debate in the philosophy of mind is concerned with the clash between certain strongly held intuitions and what science tells us about the mind and its relation to the world. What science tells us about the mind points strongly towards some version or other of physicalism. The intuitions, in one way or another, suggest that there is something seriously incomplete about any purely physical story about the mind.

For our purposes, we can be vague about the detail and think broadly of physicalism as the view that the mind is a purely physical part of a purely physical world. Exactly how to delineate the physical will not be crucial: anything of a kind that plays a central role in physics, chemistry, biology, neuroscience, and the like, along with the a priori associated functional and relational properties, count, as far as we are concerned.

Most contemporary philosophers, when given a choice between going with science and going with intuitions, go with science. Although I once dissented from the majority, I have capitulated and now see the interesting issue as being where the arguments from the intuitions against physicalism – the arguments that seem so compelling – go wrong. (p. 421)

This is a remarkable passage – remarkable for the breathtaking rhetorical sleight of hand it embodies. I do not mean to imply that Jackson is being insincere or intentionally manipulative of his readers; I am sure he is not. But – with all due respect to a philosopher whose work I have long admired, and still admire – that is only because he has evidently now “drunk the Kool-Aid” of physicalism so deeply that he is perhaps incapable of seeing how thoroughly tendentious and question-begging is his characterization of the philosophical situation.

Consider the way Jackson frames the issue here – as a debate between “science” and “intuition.” If that really were what the debate is about, how could any rational person fail to understand why Jackson has come to endorse physicalism? Indeed, how, in that case, could any rational person fail to join him in that endorsement? But in fact that is not what the debate is about; certainly Jackson has given us no reason to think it is. Jackson’s younger self certainly didn’t appeal to “intuition.” There is no such appeal in the formulation of the knowledge argument I presented above, and there is no such appeal in Jackson’s presentation in the two articles in which he first put forward the argument. Indeed, in “Epiphenomenal Qualia,” Jackson explicitly says that it is “unfair” to suggest that a qualia-based objection to physicalism must rest on an unargued intuition, explicitly distances himself from the “modal argument” against physicalism precisely because he takes it to rest on a disputable intuition, and explicitly favors the knowledge argument precisely because he there takes it to embody something more firm than an appeal to disputable intuitions!

Consider too that both sides can play the game Jackson is playing in the passage under consideration. The anti-physicalist could say:

We know from the very nature of “the physical” as that tends to be understood in contemporary philosophy that there can in principle be no physicalistic explanation of conscious experience. Arguments like the knowledge argument illustrate this point. And yet many contemporary philosophers have a strongly held intuition that a scientific view of the world requires a commitment to physicalism. Still, other contemporary philosophers, when given a choice between going with solid philosophical arguments and going with disputable intuitions, go with the solid philosophical arguments. Accordingly, they reject physicalism as a misinterpretation of science.

Is this as plausible as Jackson’s way of framing the issue? I maintain that it is far more plausible. And this brings us to the other problem with the passage from Jackson under consideration. Jackson casually assures us that “what science tells us about the mind points strongly towards some version or other of physicalism.” Physicalists say this all the time, of course. But it isn’t true, and Jackson certainly gives us no reason whatsoever to think that it is true. In fact, modern science points solidly away from physicalism, and the reason has precisely to do with the very issue Jackson thinks is “not crucial,” viz. “exactly how to delineate the physical.” For as I have noted in many places – most recently in a post on Chomsky – notions like “matter” and “the physical,” though they have (as Chomsky has rightly emphasized) at best a very elusive positive content in most modern thinking on the mind-body problem, nevertheless have also a very clear negative content. As I stated in the Chomsky post:

Whatever matter turns out to be, there are certain features that modern philosophers, and scientists in their philosophical moments, tend to refuse ever to attribute to it.

For at least some of them, this would seem to include sensory qualities like color, odor, taste, sound, and the like as common sense understands them. For the mechanistic revolution Chomsky alludes to was not merely, and indeed not even essentially, committed to the idea that material causation involves literal contact. It was also and more lastingly committed to some variant or other of a “primary/secondary” quality distinction on which there is nothing in the material world that “resembles” our “ideas” of the sensory qualities mentioned (as Locke would put it). If we want to redefine the “red” of a fire engine in terms of how its surface reflects photons at certain wavelengths, we can say that the fire engine is red. But if by “red” we mean the way red “looks” to us when we perceive it, then nothing like that exists in the fire engine, which is (if we think of color in these commonsense terms) intrinsically “colorless.” And so on for sounds, tastes, and all the rest. Color, odor, taste, sound, and the like – again, as common sense understands them (rather than as redefined for purposes of physics) – are reinterpreted by mechanism as projections of the mind, existing only in consciousness. This is the origin of the “qualia problem,” and the puzzle now becomes how to relate these “qualia” or “phenomenal properties” to the intrinsically colorless, odorless, tasteless particles that make up the brain just as much as they do external material objects.

Now if one insists on denying these sensory qualities to matter, then it seems clear that we do have a clear enough conception of “body” to generate a mind-body problem. More than that, we have a conception that clearly implies that the mind (in which alone these qualities exist) cannot be something material or bodily – that, at any rate, is the lesson drawn by early modern thinkers like Cudworth and Malebranche, and by contemporary writers like Richard Swinburne, who take the “mechanistic” conception of matter itself to entail dualism.

This lesson, I submit, is precisely what Jackson’s original knowledge argument illustrates. It shows in a new way what early modern philosophers like Descartes, Cudworth, Malebranche, and Locke, and contemporary thinkers like Nagel and Swinburne, already knew and pointed out many times over the centuries – that given the (mechanistic) understanding of “the physical” that all modern philosophers (whether they be Cartesians, idealists, or materialists) tend to take for granted, a “physicalistic” explanation of consciousness is in principle impossible. It is the moderns’ very conception of matter, rather than some “disputable intuition,” that opens the way to dualism. And insofar as modern science has committed itself to this conception of matter, it follows that modern science itself points to dualism and away from physicalism. I hasten to add, though, that this commitment is not really a “scientific” commitment at all, but a purely philosophical one.

And a mistaken one too, from the point of view of Aristotelian-Thomistic philosophers like myself. This brings me to some important remarks from Robinson’s essay. Robinson says:

The dialectical situation in which the knowledge argument is usually taken to be located is the following: it is accepted that physicalism gives an adequate account of non-conscious reality, which constitutes almost 100 percent of the universe, but struggles to accommodate certain features of mental life, namely the “what it’s like” or qualia of certain conscious states. These latter constitute “the hard problem” for physicalism. The fact that they also constitute such a tiny part of the world is presented as a reason for thinking that they cannot plausibly be held to refute a unified physicalist account.

I think that this constitutes a radical misunderstanding of the dialectical situation. What the argument really brings out is that only experience of the appropriate kind can reveal the qualitative, as opposed to purely formal and structural, features of the world. The kind of thing that Mary did not know, generalized from color vision to all the other sensible qualities, is essential to any contentful conception of the world, and physicalism without it would lack any empirical content. (p. 240)

There are two themes here that I want briefly to develop. The first is the entirely illusory character of the widespread assumption that “everything else has been given a physicalistic explanation,” so that the mind cannot plausibly be regarded as immune to such explanation. In fact, the reason it seems that “everything else has been given a physicalistic explanation” is precisely the reason that the mind cannot be “explained” in the same way. For “everything else” has been “explained” in a physicalistic manner precisely by carving off the aspects of mind-independent reality that do not fit the physicalistic model and relocating them in the mind, treating them as mere projections. Again, color, odor, sound, taste, heat, cold, and the like, as common sense understands them, were “explained” only by denying that these qualities really exist in the external physical world at all in the first place. Instead, color, odor, sound, and the rest were for purposes of physics redefined in physicalistically “respectable” terms – color in terms of surface reflectance, sound in terms of compression waves, and so on. Color, sound, etc. as common sense understands them were then reinterpreted as existing only in our conscious experience of the material world, rather than in the material world itself. In short, they are not truly “explained” at all, but just swept under the rug of the mind. (As I have argued before, the problem intentionality poses for physicalism has a similar origin.)

The early moderns generally recognized that this entails a kind of dualism – that it is simply incoherent to suppose that one can get rid of the sensory qualities so reinterpreted by further relocation and redefinition, any more than one can get rid of literal dirt that one has swept under a rug by further application of the “sweep it under the rug” strategy. Contemporary writers like Thomas Nagel see this too – see that it is precisely the physicalist’s own understanding of what “reductive explanation” involves that precludes in principle a “reductive explanation” of conscious experience itself. But contemporary physicalists, forgetful of the history of their discipline, cluelessly draw precisely the opposite conclusion: “Come on, we’ve gotten rid of all the other dirt in the room by sweeping it under the rug; so why wouldn’t we be able to deal with the dirt under the rug in the same way?”

The second theme from Robinson I want to call attention to is his suggestion that “only experience of the appropriate kind can reveal the qualitative, as opposed to purely formal and structural, features of the world.” What he is getting at is this. When the natural world is denuded of the qualitative features common sense takes it to have – color, odor, taste, sound, and the like, as we experience them in everyday life – what we are left with is an entirely abstract structure, the sort of thing physics expresses in the language of mathematics. But it is simply incoherent to regard the mind-independent world as nothing but an abstract structure; there must be something which has the structure. Moreover, to deny the existence of the qualitative features themselves – as some eliminative materialists have suggested doing as a way of “solving,” by brute force, the problem qualia pose for physicalism – would in effect be to cut off the scientific redefinition of nature from any empirical support at all. We would be denying, in the name of science, the very existence of the conscious experience from which scientific inquiry proceeds (a paradox that was not lost on the ancient Greek atomist Democritus, as I noted in an earlier post).

Bertrand Russell, E. A. Burtt, and other early twentieth-century thinkers were well aware of these problems. Russell’s solution was to suggest that the sensory qualities which the moderns had redefined as mere projections of the mind have to be put back into the natural world after all. Accordingly, something like what philosophers now call “qualia” were, for Russell, the intrinsic features of the external physical world – that which “fleshes out” or makes concrete the otherwise abstract structure described by physics. Contemporary philosophers like Michael Lockwood, David Chalmers, and Galen Strawson have followed Russell’s lead, and Robinson’s position seems to bear a family resemblance to theirs. The trouble is that, given the “mental” character modern philosophers tend to attribute to the sensory qualities, this Russellian approach seems to lead to a kind of idealism or panpsychism, on which the natural world is mental through and through (though Russell and Lockwood, at least, try to resist this consequence). This is, I think, a less mad view than physicalism is, but it is mad all the same.

From an Aristotelian-Thomistic point of view, the mistake was opting for a mechanistic-cum-quantitative conception of nature in the first place, and philosophers of mind have been on the wrong track ever since Descartes, Hobbes, and Co. The value of the knowledge argument is that it shows, as Robinson puts it, that “classical physicalism is broken-backed from the start” (p. 243). But Cartesian dualism, property dualism, idealism, panpsychism, etc. are at best only less bad than physicalism. The correct remedy is a full-blown return to Aristotelian-Thomistic hylemorphism, on which alone the quantitative picture of the world presented to us by modern science can properly be understood – as an important part of the correct story about the natural world, but never the whole story.

Give me that old time atheism

Last night I was dipping into Roy Abraham Varghese’s Great Thinkers on Great Questions, an interesting collection of interviews with a number of prominent philosophers (including A. J. Ayer, G. E. M. Anscombe, Alvin Plantinga, Richard Swinburne, Ralph McInerny, Brian Leftow, Gerard Hughes, and many others) on topics mostly related in one way or another to religion. Some of Ayer’s remarks brought to mind how different earlier generations of agnostics and atheists had been, not merely culturally (as Roger Scruton has noted) but philosophically. Ayer, though a notorious lifelong foe of religion, was not a materialist. In his famous book Language, Truth, and Logic, he attempted (as he reminds us in the Varghese volume) to reduce physical objects to “sense-contents,” entities which were intended to be neutral between mind and matter but which were in fact (as Ayer admits) closer to the mental than to the physical side of the traditional mental/physical divide. Hence the resulting position was “much more nearly mentalistic than physicalistic.” And to the end of his life he apparently always rejected any attempt to reduce the mental to the physical.

The reason for this is that even agnostic and atheist philosophers of Ayer’s generation generally recognized that materialism is just prima facie implausible. As I have noted in some earlier posts (here and here), and as I discuss at length in The Last Superstition, dualism was by no means a deviation from the broadly mechanistic conception of matter contemporary philosophy has inherited from the 17th century, but rather a natural consequence of that conception, given its highly abstract and mathematical redefinition of the material world. If matter is what the mechanistic view says it is, then (it seems) there is simply nowhere else to locate color, odor, taste, sound, etc. (as common sense understands these qualities, anyway), and nowhere else to locate meaning (given the banishment of final causes from the material world), than in something immaterial. And until about the 1960s, most philosophers (the occasional exception like Hobbes notwithstanding) seemed to realize that, short of returning to an Aristotelian hylemorphic philosophy of nature, the only plausible alternatives to dualism were views that tended to put the accent on mind rather than on matter – such as idealism, phenomenalism, or neutral monism.

The last of these, as its name implies, was officially committed to the view that the basic stuff out of which the world is constructed is “neutral” between mind and matter, but notoriously it tends to collapse into either phenomenalism or idealism. In my atheist days, it was the version of neutral monism developed by Bertrand Russell (or rather a riff on that version developed by F. A. Hayek) that I took to be the most plausible approach to the mind-body problem. (In recent philosophy, Russell’s views have been developed, in a way that seeks to avoid any sort of idealism, by Michael Lockwood; and, in a way that to some extent or other concedes their idealistic implications, by Galen Strawson and David Chalmers. In my Russellian days I was more attracted to Lockwood’s approach.) After a brief flirtation with materialism while an undergrad, I was more or less inoculated against it by John Searle’s writings, and came to regard the Russellian approach as the most plausible way to defend a naturalistic (if non-materialistic) view of the world.

Most naturalistic philosophers are not at all attracted to this approach, however, precisely (I would suggest) because of its tendency to collapse into some sort of philosophical idealism. For to make mind out to be the ultimate reality is – as the history of 19th century idealism shows – to adopt a view which must surely strike most naturalists as “too close for comfort” to a religious view of the world. To be sure, Chalmers and Strawson do not take their position in anything like a religious direction, but so far few other naturalists have been willing to follow them.

But if they were wise, they would do so. Chalmers and Strawson are in fact among the most interesting philosophers of mind writing today, in part because of their attempt to defend a kind of naturalism while acknowledging the very deep philosophical difficulties inherent in materialism. (Strawson famously dismisses materialism as “moonshine.”) As I have been lamenting in recent posts, most contemporary philosophical naturalists (to say nothing of non-philosophers who are naturalists, such as the New Atheists) have only the most crude understanding of the theological views they dismiss so contemptuously. In the same way, they tend also to be absurdly overconfident about the prospects of a materialist or physicalist account of the mind.

Earlier generations of philosophical atheists or agnostics – Ayer, Russell, Popper, to name just three – knew how difficult it is to defend such an account, and thus avoided grounding their atheism or agnosticism in a specifically materialist metaphysics. Some of their contemporary successors – Lockwood, Chalmers, Strawson, Nagel, Searle, Fodor, McGinn, Levine, among others – have, to varying degrees, some awareness of the same problems. Consequently, at least some of these people realize that naturalism itself (which seems most plausible precisely when spelled out in materialist terms) is by no means obviously right; it is something that requires a very great deal of effort to defend, and cannot blithely dismiss its rivals. Unfortunately, the bulk of contemporary philosophical naturalists – Dennett and Rey being by no means idiosyncratic in this regard – seem forever lost in their dogmatic slumbers.

ADDENDUM: I should note that Strawson does sometimes call his version of Russell's position "real materialism," and that Lockwood has occasionally said similar things. By contrast, Grover Maxwell, another Russellian who influenced both Lockwood and Strawson, repudiates any kind of "materialist" label even though his views are more or less identical to theirs. And Chalmers sometimes characterizes his own variation on Russellianism as a kind of "dualism"! So, the terminology here can get confusing. The point is that all of these authors reject materialism in the standard (Smart, Armstrong, early Putnam, Davidson, Dennett, Churchland, et al.) sense.

Descartes’ “indivisibility” argument

In the sixth of his Meditations on First Philosophy, Descartes writes:

[T]here is a vast difference between mind and body, in respect that body, from its nature, is always divisible, and that mind is entirely indivisible.  For in truth, when I consider the mind, that is, when I consider myself in so far only as I am a thinking thing, I can distinguish in myself no parts, but I very clearly discern that I am somewhat absolutely one and entire; and although the whole mind seems to be united to the whole body, yet, when a foot, an arm, or any other part is cut off, I am conscious that nothing has been taken from my mind; nor can the faculties of willing, perceiving, conceiving, etc., properly be called its parts, for it is the same mind that is exercised [all entire] in willing, in perceiving, and in conceiving, etc.  But quite the opposite holds in corporeal or extended things; for I cannot imagine any one of them [how small soever it may be], which I cannot easily sunder in thought, and which, therefore, I do not know to be divisible.  This would be sufficient to teach me that the mind or soul of man is entirely different from the body, if I had not already been apprised of it on other grounds.

Naturalism in the news

On the subject of naturalism, Raymond Tallis opines in The Guardian, Massimo Pigliucci reports at Philosophy Now, and Daniel Dennett is interviewed at 3:AM Magazine.  James Ladyman, co-author of the influential Every Thing Must Go: Metaphysics Naturalized, gets a prominent mention in each piece.  Which gives me an excuse for some photoshopping fun (with apologies both to Ladyman and to Tim Meadows).

Nagel and his critics, Part VII

Let’s return to our look at the critics of Thomas Nagel’s Mind and Cosmos.  New commentary on Nagel’s book continues to appear, and to some extent it repeats points made by earlier reviewers I’ve already responded to.  Here I want to say something about Mohan Matthen’s review in The Philosophers Magazine.  In particular, I want to address what Matthen says about the issue of whether conscious awareness could arise in a purely material cosmos.  (Matthen has also commented on Nagel’s book over at the New APPS blog, e.g. here.)

Nagel and his critics, Part VIII

Resuming our series on the serious critics of Thomas Nagel’s Mind and Cosmos, let’s turn to Simon Blackburn’s review in New Statesman from a few months back.  Blackburn’s review is negative, but it is not polemical; on the contrary, he allows that the book is “beautifully lucid, civilised, modest in tone and courageous in its scope” and even that there is “charm” to it.  Despite the review’s now somewhat notorious closing paragraph (more on which below) I think Blackburn is trying to be fair to Nagel.

Nagel and his critics, Part IV

Continuing our look at the critics of Thomas Nagel’s recent book Mind and Cosmos, we turn to philosopher Alva Noë’s very interesting remarks over at NPR’s 13.7: Cosmos & Culture blog.  Noë’s initial comments might seem broadly sympathetic to Nagel’s position.  He writes:

Science has produced no standard account of the origins of life.

We have a superb understanding of how we get biological variety from simple, living starting points. We can thank Darwin for that. And we know that life in its simplest forms is built up out of inorganic stuff. But we don't have any account of how life springs forth from the supposed primordial soup. This is an explanatory gap we have no idea how to bridge.

Science also lacks even a back-of-the-envelop [sic] concept explaining the emergence of consciousness from the behavior of mere matter. We have an elaborate understanding of the ways in which experience depends on neurobiology. But how consciousness arises out of the action of neurons, or how low-level chemical or atomic processes might explain why we are conscious — we haven't a clue.

We aren't even really sure what questions we should be asking.

These two explanatory gaps are strikingly similar… In both cases we have large-scale phenomena in view (life, consciousness) and an exquisitely detailed understanding of the low-level processes that sustain these phenomena (biochemistry, neuroscience, etc). But we lack any way of making sense of the idea that the higher-level phenomena just come down to, or consist of, what is going on at the lower level.

Michael Rea owes Richard Swinburne an apology

Richard Swinburne, emeritus professor of philosophy at Oxford University, author of many highly influential books, and among the most eminent of contemporary Christian thinkers, recently gave the keynote address at a meeting of the Society of Christian Philosophers (SCP).  In his talk, which was on the theme of sexual morality, he defended the view that homosexual acts are disordered – a view that has historically been commonly held within Christianity and the other major world religions, has been defended by philosophers like Plato, Aquinas, and Kant, and is defended to this day by various natural law theorists.  So, it would seem a perfectly suitable topic of discussion and debate for a meeting of Christian philosophers of religion.  Of course, that view is highly controversial today.  Even some contemporary Christian philosophers disagree with Swinburne.  I wasn’t there, but apparently his talk generated some criticism.   Fair enough.  That’s what meetings of philosophers are about – the free and vigorous exchange of ideas and arguments.

Some brief arguments for dualism, Part IV

The arguments for dualism considered so far in this series (see here, here, and here) have been more or less “modern” rather than “classical.” They focus on those aspects of the mind most familiar to contemporary philosophers, namely intentionality (the meaningfulness or directedness beyond themselves of thoughts and the like) and qualia (those aspects of a conscious experience which are directly knowable only via introspection, and thus only by the one undergoing the experience). And they contend that, given the mechanistic conception of matter taken for granted by modern philosophers (dualists and materialists alike), these features of the mind are necessarily immaterial.

Classical arguments for the immateriality of the mind, by which I mean the sort common within Western philosophy prior to Descartes and defended by the likes of Plato, Aristotle, and Aquinas, are very different. You won’t find the latter thinkers going on about either qualia or intentionality, because the very notions of qualia and intentionality, as usually understood, are artifacts of the modern mechanistic re-conception of the material world. “Qualia” are what you get when you deny that matter can have anything like the sensible qualities it seems to have in ordinary experience. “Intentionality” is what you get when you insist that the material world is devoid of anything like final causality, when you go on accordingly to relocate all meaning and purpose within the mind, and when you also go on in turn to characterize mental states as internal “representations” of an external reality. I have said a little bit about all of this in earlier posts, and it is a theme I explore in great detail in The Last Superstition.

For Plato, Aristotle, Aquinas, and other ancients and medievals, the main reason why the mind has to be immaterial concerns its affinity to its primary objects of knowledge, namely universals, which are themselves immaterial. When properly fleshed out and understood, this sort of argument is in my view decisive. Yet it has received very little attention from contemporary philosophers, partly, I think, because of their general ignorance of what the ancients and medievals thought, and partly because the logic of the mechanistic revolution inaugurated by Galileo, Descartes, Hobbes, Locke, et al. has pushed them into so cramped and narrow a conceptual space that they can hardly even conceive any alternative to it. The result is that when they do address the arguments of the ancients and medievals (concerning this subject or any other), they almost always distort them in the most grotesque fashion, anachronistically reading into them assumptions that make sense only if one takes for granted conceptions of matter, mind, causation, etc. that the older thinkers in question would have regarded as deeply mistaken and muddleheaded. (Thus is Aristotle made out to be a “functionalist” vis-à-vis the mind, Aquinas’s Fifth Way is read as if it were an anticipation of Paley’s feeble “design argument,” etc.)

In The Last Superstition, I explain at length why some form of realism about universals is rationally unavoidable. (Whether it is the Platonic form of realism, the Aristotelian one, or the Scholastic one that we should endorse is a separate matter irrelevant to present purposes.) I am not going to attempt to summarize that case here, but the examples to follow should suffice to give a sense of how an argument from the reality of universals to the immateriality of the mind might proceed. Readers wanting a fuller treatment should consult TLS.

Consider that when you think about triangularity, as you might when proving a geometrical theorem, it is necessarily perfect triangularity that you are contemplating, not some mere approximation of it. Triangularity as your intellect grasps it is entirely determinate or exact; for example, what you grasp is the notion of a closed plane figure with three perfectly straight sides, rather than that of something which may or may not have straight sides or which may or may not be closed. Of course, your mental image of a triangle might not be exact, but rather indeterminate and fuzzy. But to grasp something with the intellect is not the same as to form a mental image of it. For any mental image of a triangle is necessarily going to be of an isosceles triangle specifically, or of a scalene one, or an equilateral one; but the concept of triangularity that your intellect grasps applies to all triangles alike. Any mental image of a triangle is going to have certain features, such as a particular color, that are no part of the concept of triangularity in general. A mental image is something private and subjective, while the concept of triangularity is objective and grasped by many minds at once. And so forth. In general, to grasp a concept is simply not the same thing as having a mental image. (Again, see TLS for more details.)

Now the thought you are having about triangularity when you grasp it must be as determinate or exact as triangularity itself, otherwise it just wouldn’t be a thought about triangularity in the first place, but only a thought about some approximation of triangularity. Yet material things are never determinate or exact in this way. Any material triangle, for example, is always only ever an approximation of perfect triangularity (since it is bound to have sides that are less than perfectly straight, etc., even if this is undetectable to the naked eye). And in general, material symbols and representations are inherently always to some extent vague, ambiguous, or otherwise inexact, susceptible of various alternative interpretations. It follows, then, that any thought you might have about triangularity is not something material; in particular, it is not some process occurring in the brain. And what goes for triangularity goes for any thought that involves the grasp of a universal, since universals in general (or at least very many of them, in case someone should wish to dispute this) are determinate and exact in a way material objects and processes cannot be.

As James F. Ross has argued, some of the best-known arguments of twentieth-century analytic philosophy reinforce this judgment. For instance, Quine’s arguments for the indeterminacy of translation and Kripke’s argument regarding “quaddition” show that there is in principle nothing in the facts about human behavior or physiology, or in any other physicalistically “respectable” set of facts, that can determine (say) whether by “gavagai” I mean “rabbit” or “undetached rabbit part,” or whether I am doing addition rather than “quaddition.” Indeed, these arguments show that this same indeterminacy afflicts everything I say or do. Yet it is simply false that everything I say or do is indeterminate in this way. For example, should I deploy modus ponens in defending a Quine- or Kripke-style argument, what I will be deploying is indeed modus ponens and not some mere approximation of modus ponens; certainly it had better be modus ponens and not some mere approximation, otherwise my arguments would all be invalid. Nor will it do to suggest that maybe all my arguments really are invalid, for even to deny that I ever really use modus ponens but only ever approximate it requires that I first grasp determinately what modus ponens is before judging that I never really engage in it. Similarly, if someone wanted to deny that we ever really grasp perfect triangularity, he would first have to grasp it himself before going on to judge (obviously falsely, in that case) that it is something we never grasp.

So, there is no coherent sense to be made of the suggestion that all of our thoughts are indeterminate. But if at least some of them are determinate, and no physical process or set of physical facts is ever determinate, it follows that at least some of our thoughts are not physical. (Ross’s argument, by the way, is elegantly developed in his article “Immaterial Aspects of Thought,” which appeared in the Journal of Philosophy in 1992. A later version of this article is available at his website, in the form of a chapter of his book manuscript Hidden Necessities.)

That is one way an argument from realism about universals to the immateriality of the mind can be developed. There are other ways too, which I will summarize in future posts.

Whatever one thinks of arguments like this, it is important to understand that (like the other arguments I’ve presented in this series) they are not the sort that might be undermined by the findings of neuroscience, or any other empirical science for that matter. They are not “soul of the gaps” arguments which purport to give a quasi-scientific explanation of some psychological phenomenon that we simply haven’t got enough empirical data to explain in a materialistic way. Rather, they purport to show that it is in principle impossible, conceptually impossible, for the intellect to be accounted for in a materialistic way. If such arguments work at all, they establish conclusively that the intellect could no more be identified with processes in the brain than two and two could make five. If they are mistaken, they would be mistaken in the way one might make a mistake in attempting to carry out a geometrical proof, and not by virtue of having failed to take account of this or that finding of brain research.