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.

Fodor’s trinity

What is the mind-body problem? In an article summarizing his work, which he wrote for Samuel Guttenplan’s A Companion to the Philosophy of Mind, Jerry Fodor answers as follows:

[S]ome of the most pervasive properties of minds seem so mysterious as to raise the Kantian-sounding question how a materialistic psychology is even possible. Lots of mental states are conscious, lots of mental states are intentional, and lots of mental processes are rational, and the question does rather suggest itself how anything that is material could be any of these.

For Fodor, then, there are really three mind-body problems: the problem of consciousness, the problem of intentionality, and the problem of rationality. Why are the phenomena in question problematic?

Let’s look at each briefly. (The following characterizations are mine, not Fodor’s.) When light strikes your retinas, a complex series of neural processes is initiated which may result in one of a range of possible behaviors – taking steps to avoid an obstacle, sorting red apples from green ones, or saying “It’s sunny outside.” When light strikes an “electric eye” or photodetector of some sort, electrical processes are initiated which also may result in one among a range of possible behaviors – the setting off on an alarm, for example, or, if the device is associated with a robot, perhaps behavior similar to the sort you might exhibit, such as avoiding an obstacle, sorting objects, or declaring (through a speech synthesizer) that it is sunny. Now, in the case of the electric eye and its associated robot, what we can observe going on in the system is presumably all there is. The system has no “inner life” or conscious visual experience associated with the electrical activity and behavior. But we do have conscious awareness; we do have an “inner life.” There is “something it is like” for us to see things, whereas there is nothing it is like for the robot to “see” something. Or as contemporary philosophers like to say, we have qualia while the robot appears not to. So, what accounts for this difference? It does not seem plausible to hold that it can be accounted for merely in terms of the greater complexity of the human brain, because the difference between conscious systems and unconscious ones seems clearly to be a difference in quality and not merely of quantity. This is the problem of consciousness.

Then there is the problem of intentionality, which concerns, not just intentions, but meaning in general. (The technical term “intentionality” derives from the Latin intendere, which means “to point at” or “to aim at,” as a word or thought points to or aims at the thing that it means.) Suppose we say that within the robot of our example there is a symbolic representation that means that it is sunny outside. Though the representation has this meaning, it has it only because the designers of the robot programmed the system so that it would be able to detect weather conditions and the like. The electrical processes and physical parts of the system would have had no meaning at all otherwise. By contrast, the thoughts of the designers themselves have meaning without anyone having to impart it to them. As John Searle has put it, the robot’s symbolic representations – like words, sentences, and symbols in general – have only derived intentionality, while human thought has original or intrinsic intentionality. What can account for the difference, especially if we assume that human beings are no less material than robots? That, in a nutshell, is the problem of intentionality.

Consider also that we are able not only to have individual meaningful thought episodes, but also to infer to further thoughts, to go from one thought to another in a rational way. This is not merely a matter of one thought causing another; a lunatic might be caused to conclude that mobsters are trying to kill him every time he judges that it is sunny outside, but such a thought process would not be rational. Rather, we are able to go from one thought to another in accordance with the laws of logic. Now, it might seem that the robot of our example, and computers generally, can do the same thing insofar as we can program them to carry out mathematical operations and the like. But of course, we have had to program them to do this. We have had to assign a certain interpretation to the otherwise meaningless symbolic representations we have decided to count as the “premises” and “conclusion” of a given inference the machine is to carry out, and we have had to design its internal processes in such a way that there is an isomorphism between them and the patterns of reasoning studied by logicians. But no one has to assign meaning to our mental processes in order for them to count as logical. So, what accounts for the difference? How are we able to go from one thought to another in accordance, not just with physical causal laws, but in accordance with the laws of logic? That is the problem of rationality.

Most contemporary philosophers of mind would, I think, agree with Fodor that this trinity of issues constitutes the mind-body problem, and I think they would also more or less agree with my statement of the problems. They do not necessarily agree about how difficult the problems are. Of the three, the problem of rationality seems to get the least attention from contemporary philosophers. Fodor himself thinks that this problem is the one contemporary philosophers have most plausibly been able to solve in a way that vindicates materialism, and that they have done so (contrary to what my statement of the problem suggests) precisely by thinking of rational thought processes as computational processes over formal symbols encoded in the brain. Most other contemporary philosophers of mind seem to agree with Fodor about this much, though there are prominent dissenters, such as Searle, Dreyfus, and defenders of the anti-materialist “argument from reason.” The greatest of the ancient and medieval philosophers would have sided with the dissenters; for Plato, Aristotle, Aquinas, et al., rationality was the aspect of human nature that could not possibly involve a material organ. (We will come back to this point.)

Contemporary philosophers, by contrast, are obsessed with the problem of consciousness, and in particular with “qualia” – something you do not see the ancients and medievals worrying about at all, certainly not as something that pointed to any immaterial aspect of human nature. Fodor, like many other contemporary philosophers of mind, regards this as “the hard problem” for materialism. The problem of intentionality also gets a lot of attention from contemporary philosophers. My sense is that in general they tend to find it more challenging than the problem of rationality but not as challenging as the problem of consciousness. My own view is that, at least as contemporary philosophers tend to understand the problem, it is in fact as great or even greater a difficulty for materialism than the problem of consciousness is. The ancients and medievals would, I think, have agreed, though they would have regarded the problem as pointing to an immaterial aspect of human nature only to the extent that it overlaps with the problem of rationality.

The reason for all this is that the problems of consciousness and intentionality, as they are understood by modern philosophers anyway, are not (as they are often assumed to be) “perennial” problems of philosophy, but rather an artifact of certain historically contingent metaphysical assumptions early modern philosophers like Descartes, Hobbes, Locke, and Co. put at the center of Western thought. In particular, they are an artifact of the “mechanistic” revolution I have discussed and criticized so frequently on this blog and in my books The Last Superstition and Aquinas.

I have explained how this is so at length, both in those books and in previous posts, but here is a brief summary. On the older, Aristotelian-Scholastic understanding of the natural world that the early modern thinkers overthrew, qualities like color, sound, odor, taste, heat and cold were taken to exist in the material world more or less in just the way common sense supposes that they do. The moderns, reviving the view of the ancient atomists, denied this: For them, the natural world is made up of intrinsically colorless, odorless, soundless, tasteless particles in motion, and the qualities in question exist only in the mind of the observer. For purposes of physics, we can in their view redefine heat and cold in terms of molecular motion, or red and green in terms of the different surface reflectance properties of physical objects, but heat, cold, red and green as common sense understands them exist only in consciousness. But since the brain is on this view made up of inherently colorless, odorless, tasteless particles no less than any other physical object, this seems inevitably to entail that consciousness is not a feature of the brain – which is, of course, exactly what Descartes, Malebranche, Locke, and other early modern thinkers concluded insofar as they embraced dualism. Therein lies the origin of what contemporary writers call the “qualia problem” or the problem of consciousness.

The older, Aristotelian-Scholastic view also held that a kind of meaning, teleology, or goal-directedness is built into the structure of the material world from top to bottom. This includes not just the usual examples – the functions of bodily organs – but basic causal relations as well. For the Scholastics, if some cause A predictably generates some specific effect or range of effects B, this can only be because A inherently “points to” or “aims at” B. Generating B, specifically – rather than C, or D, or no effect at all – is what Aristotelians would call the “final cause” of A. Causing B is what A will naturally tend to do unless impeded. Now the early moderns eliminated final causality from their picture of the natural world; this was and has remained the core of a “mechanistic” conception of nature. For them there is no teleology built into nature, no purposiveness or goal-directedness. There are brute, meaningless cause and effect patterns, but no reason inherent in nature why a cause should have just the effects it does have. One result of this was to open the way to the puzzles about causation raised by David Hume. More relevant to our interests here, though, is that it made intentionality particularly problematic. If nothing in the material world inherently “points to” or “aims at” anything else – if matter is comprised of nothing more than inherently purposeless, meaningless particles in motion – then, since the brain is made up of these particles no less than any other material object is, it seems to follow that the intentionality of our thoughts, that by virtue of which they inherently “point to,” “aim at,” or mean something beyond themselves, cannot be any sort of material property of the brain. Thus is generated the problem of intentionality.

So, Fodor’s trinity of “mind-body problems” very much reflects a modern set of assumptions about the nature of the physical world. It also reflects a presumption of materialism insofar as Fodor, like so many other contemporary philosophers, writes as if the question to ask were “How do we explain these phenomena in material terms?” Of course, a modern dualist would say that these phenomena cannot be explained in material terms, so that the right question to ask is “Given that these phenomena are not material, how are they related to material phenomena? For example, do they interact causally with them, and if so, how?” You might say that what the mind-body problem is is in part determined by how one thinks it should be solved. (“But how does positing immaterial mind-stuff explain things any better?” A common materialist retort, but not a good one, for reasons I have explained here and here.)

Notice also that Fodor says nothing about the “body” side of the mind-body problem – as if matter were unproblematic and only mind posed any philosophical difficulties. As I have noted recently, a number of prominent contemporary philosophers have emphasized that this is by no means the case. And from an Aristotelian-Scholastic point of view, the moderns’ standard assumptions about matter are perhaps even more problematic than their assumptions about mind. “Qualia” can seem necessarily immaterial only if we assume that matter is as the ancient atomists and their modern successors assume it to be; the “qualia problem,” which many modern materialists regard as such a challenge to their position (as Democritus himself did) is a problem that their own favored conception of matter created. The same is true of the problem of intentionality, at least if that is taken essentially to involve the problem of how something material can “point to” or be “directed at” something else. From an Aristotelian-Scholastic point of view, since matter is not as the atomists take it to be, and immanent final causality or teleology pervades the material world from top to bottom anyway, there is no special difficulty in regarding qualia and (at least many instances of) intentionality as in some significant sense “natural” or even “material” phenomena.

Things are very different, though, where intentional phenomena having a conceptual structure are concerned, as well as where reasoning is concerned. Here is where the Aristotelian-Scholastic tradition locates an immaterial element to human nature. The reason, in a nutshell, is that the objects of our thoughts are universal rather than particular, and determinate or exact rather than indeterminate or ambiguous; that the thoughts themselves inherit this universality and determinacy; and that nothing material can possibly be universal and determinate in this way. This is, of course, a very large topic deserving a discussion of its own. I have explored it in more detail in earlier posts (e.g. here and here) as well as in chapter 4 of Aquinas and chapter 7 of Philosophy of Mind. (The most thorough recent defense of the line of thought in question is probably the one offered in the late James Ross’s article “Immaterial Aspects of Thought.”)

The “dualism” that results is very different from the Cartesian variety, though. For the mind (or more precisely, the intellect) is not a substance on the Aristotelian-Scholastic view, but rather a power of the soul, and the soul in turn is not a substance either (or at least not a complete substance) but rather the substantial form of the living human body. Neither is the body a substance. It is rather only soul and body together which make a complete substance, where soul and body are just one instance among innumerable others of the hylemorphic form/matter relationship that exists in every material substance. Accordingly, there is no “interaction problem” of the sort that faces the Cartesian. Such a problem arises when we think of the mind as an “immaterial substance” (or as a collection of “immaterial properties”) which must somehow interact with a (mechanistically-defined) material substance via what Aristotelians would call efficient causation. But from an Aristotelian-Scholastic point of view, that is simply a category mistake, or rather a collection of category mistakes. Intellect is rather one of a myriad of powers the soul imparts to the human animal of which it is the substantial form. Thus it is formal causation which relates soul (and therefore mind) to body, not efficient causation. (I have discussed this issue in more detail here, here, and here.)

All of this is bound to sound very odd to the average contemporary philosopher. It will not sound odd, though, to those familiar with the rich conceptual apparatus of the Aristotelian-Scholastic tradition, a system of thought of which most contemporary philosophers of mind are ignorant, or at best know only through the caricatures peddled by early modern philosophers. Working one’s way out of the metaphysical assumptions moderns typically bring to bear on these issues is very difficult and takes time; the temptation is always to try to translate the thought of a Plato, an Aristotle, or an Aquinas into categories contemporary philosophers are familiar with, when what we ought to be doing is recognizing that it is precisely those categories the ancients and medievals would challenge. Thus are Plato the “proto-Cartesian,” Aristotle the “functionalist,” and other ahistorical Frankenstein monsters created. (I had not sufficiently freed myself of such modern assumptions when I wrote Philosophy of Mind, in which there is still too much Cartesianism. Chapter 4 of Aquinas provides a corrective, and a more detailed treatment of how thoroughly wrong contemporary philosophers of mind get the conceptual lay of the land, from an Aristotelian-Thomistic point of view.)

So, from an Aristotelian-Scholastic point of view, the materialist’s “problem” of explaining the three purported kinds of mental phenomena in material terms (where “matter” is understood mechanistically) and the Cartesian’s “problem” of explaining mind-body interaction are pseudo-problems. In short, while for Fodor and other contemporary philosophers of mind there are three mind-body problems, for the Aristotelian-Scholastic philosopher, there is no mind-body problem at all.

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.

Stoljar on intentionality

Daniel Stoljar’s new book Physicalism is a very useful overview of its subject. However, its brief treatment of intentionality (and of some other topics too) evinces a deep misunderstanding of dualism, a misunderstanding that seems to be very common in contemporary philosophy of mind.

Stoljar begins his discussion with the following characterization of intentionality:

The intentionality of a mental state is its aboutness. When I think of Vienna or believe that the computer is on the desk or fear that the planet will get hotter, I instantiate mental states which are in a hard to define sense about Vienna, or the computer on the desk or planet Earth. The idea is that mental states (and speech acts) have a property rather like signs, sentences, and gestures; that is, they are about or represent things other than themselves. (p. 200)

So far so good; at least, that is an accurate characterization of what modern philosophers, whether physicalists, dualists, or idealists, tend to mean by “intentionality.” (Whether they are right to think of it this way is a question I will return to later.) Stoljar then suggests that the reason intentionality is philosophically problematic is that it is supposed to involve a relation that might hold between a thinker and something else, and yet lacks three key features one would expect such a relation to have. First, if I bear a relation to something else, one would expect that that something else exists; and yet I can think about something that does not exist (e.g. Valhalla). Second, if I bear a relation to something else, one would expect that there is some particular thing I bear it to; but I can think about a man without there being some man in particular I am thinking of. Third, if I bear a relation to some thing A and A = B, then one would expect that I thereby bear that relation to B; but if I am thinking about Vienna, then even though Vienna is the birthplace of Schubert, it doesn’t follow that I am thinking about the birthplace of Schubert, about whom I may know nothing. (To use the technical jargon, ascriptions of intentional mental states are often non-extensional or intensional, insofar as we cannot always substitute co-referring expressions salve veritate; that is to say, intentionality-with-a-t is often – though, it is important to note, not always – associated with intensionality-with-an-s.)

Now, Stoljar acknowledges that these features of intentionality are philosophically puzzling. But he claims that they pose no special difficulty for physicalism. In particular, they give us no reason to favor dualism over physicalism, for they are as problematic on the former view as on the latter. Says Stoljar: “[S]uppose classical dualism is true and I am some sort of complex of an ordinary physical object and soul; it is still impossible for me to stand in a relation to things that don’t exist! In sum, the paradoxes of intentionality will remain whether physicalism is true or not, hence they do not concern physicalism.” (p. 201)

There are two problems with this. First, it does not get to the heart of the problem of intentionality. Second, it rests on a misunderstanding of dualism. Let’s take them in order.

Consider the following dialogue:

Policeman: Ma’am, some bad news, I’m afraid. Your son just robbed a liquor store. Caught him red-handed with the cash tucked in the glove compartment, along with a few bottles of Tanqueray, vermouth, and tipsy olives that he tossed in the back seat.

Mom: Oh dear. I suppose he’s in trouble for being under 21. Or was he speeding in the getaway car?

Policeman: Well, there is that, I guess. But here’s the main thing: He robbed a liquor store.

Stoljar reminds me a little bit of Mom. Yes, the “paradoxes of intentionality” that he calls attention to are important. But it is intentionality itself, and not the “paradoxes,” that is of the greatest interest. Even if the objects I thought about always existed, or were always particular, or never generated non-extensional contexts – that is to say, even if intentionality exhibited none of the “paradoxical” features in question – the “aboutness” of my thoughts would remain. And it is that “aboutness” that the dualist takes to pose the chief difficulty for physicalism.

There are at least two ways to see how – a commonsense way and a more technical way. The commonsense way is this. Consider the word “cup” as you might write it in ink. Now consider a set of splotches that forms after your ink bottle leaks overnight, among which there are three right next to each other that by chance look vaguely like this: CUP. The set of splotches looks like the word, but it isn’t. The word has meaning, the splotches do not. But this has nothing to do with the physical properties of either. The ink is the same in both cases, as are the shapes. We can even imagine a case where your penmanship is bad enough and/or the splotches are distinct enough that their appearance is indistinguishable from the word “cup” that you’ve written. In general, it is not the intrinsic physical properties of letters, words, and sentences, whether written or spoken, that give them the meaning they have. Rather, their meaning derives from the conventions established by language users. It is an accident of history that the sequence of shapes cup has meaning and the sequence of shapes - ( ^ does not. Intrinsically, the first sequence is as meaningless as the second. But what is true of ink splotches and sounds seems no less true of all other physical phenomena. They all seem obviously devoid of meaning until someone decides to use them to convey meaning. As John Searle puts it, words, sentences, and the like, considered as material objects, have only “derived intentionality.” We are able to impart meaning to them by virtue of having thoughts with “original intentionality” – your thought about a cup represents or means cup without anyone having to form a convention of using it to mean that. But if neural processes are as devoid of original intentionality as ink marks, sounds, and the like, then it is hard to see how thoughts could be identified with neural processes, or claimed to supervene upon them. And the same is true of any other purported physicalistic basis for mental phenomena.

Now, there are various things a physicalist might want to say in response to this, but the point is that the problem intentionality is claimed to pose for physicalism here can obviously be stated in a way that makes no reference to the “paradoxes of intentionality.” If the commonsense point just made constitutes a difficulty for physicalism, it would do so even if the paradoxes in question did not exist.

The more technical way of making the point is to emphasize that the conception of “the physical” that physicalism typically presupposes is a mechanistic one – that is to say, one which (as I have discussed ad nauseam, e.g. here) takes matter to be devoid of any immanent or intrinsic final causality or teleology of the sort affirmed by the Aristotelian-Scholastic tradition the early moderns sought to overthrow. For the Scholastics, efficient causes in the natural order inherently “point to” or are “directed at” their effects, and in sweeping aside immanent final causality the moderns rejected the claim that any natural phenomenon inherently and irreducibly “points to” or is “directed at” anything at all. Intrinsically, the natural world is for them comprised instead of “nothing but” meaningless, purposeless particles in motion or the like. (Descartes, Locke, Boyle, Newton, and other early mechanists did of course think of ends or goals being imposed on the world by God, but precisely because they were mechanists opposed to Aristotelianism and Scholasticism, they saw the resulting purposes or meanings as extrinsic to the world rather than inherent. See the great many posts on this theme that I’ve written over the last several months, as well as the discussions in The Last Superstition and Aquinas.)

Now, if intentionality involves something “pointing to” or being “directed at” or “about” something beyond itself, and the mechanistic conception of matter underlying physicalism holds that there is no such thing in nature as something inherently and irreducibly being “directed at” or “pointing to” something else, then it seems at the very least difficult to see how intentionality could possibly be something material or physical. I had reason to make this point in my recent post on Chomsky. But though Stoljar quotes the same passage from Jerry Fodor that I cited there, he does not see (as Fodor does, though Fodor does not make explicit reference to the anti-Aristotelian mechanistic revolution) that it is the moderns’ own conception of matter, rather than the “paradoxes of intentionality,” that generates the difficulty.

Again, the point is not that the physicalist might not have a good response to points like the ones I’ve been making – I don’t think so, but that’s another issue. The point is rather that it misses the point to address the problem of intentionality as if the paradoxes Stoljar calls attention to were at the heart of it, and as if it had nothing to do with the nature of “the physical.” Both the commonsense point and the technical point (as I have called them) show that the problem has very much to do with the nature of the physical, and nothing essentially to do with the paradoxes.

But how, the physicalist might still ask, does dualism fare any better? For as Stoljar suggests, wouldn’t any objection to a physicalist account of intentionality apply mutatis mutandis to any dualist alternative? Or as Clayton Littlejohn once objected in a remark in Victor Reppert's combox: “It seems like causal pathways in an immaterial substance would have the same content fixation problems as causal pathways in a physical substance.”

As I have said, this sort of objection seems increasingly common in contemporary philosophy of mind, but it is deeply confused. What dualist ever said anything about “causal pathways in an immaterial substance”? Stoljar and Littlejohn seem to think that what the dualist means by an immaterial substance or soul is something that is just like a material substance – and in particular, something with distinct and causally interrelated parts – only not material, but instead “made out of” some other kind of “stuff” (“ectoplasm” maybe). In short, a kind of ghostly machine, but a machine all the same. But that is precisely what dualists – whether of a Platonic, Thomistic, or Cartesian stripe – do not think the soul is. For dualists have typically held that the soul is simple or non-composite, and thus not “made out of” causally interrelated parts of any sort. That its activities cannot be modeled on those of a material substance is the whole point.

How should we think of it, then? For the Cartesian, the essence of the soul is thought, and that is the entirety of its essence. Descartes does not say: “Gee, it’s hard to see how intentionality could be explained in terms of causal relations between physical parts. I therefore postulate an immaterial substance with immaterial parts whose causal relations are capable of generating thought and intentionality.” That would imply that in addition to thought, a soul has of its nature the various parts in question and their characteristic interrelations. And that is just what Descartes denies. A Cartesian immaterial substance doesn’t generate thinking. It is thinking, and that is all that it is. For that reason, and contrary to what Stoljar assumes, the Cartesian conception of intentionality cannot possibly be open to the same objections raised against physicalism. To say “Maybe a Cartesian immaterial substance – that is to say, something which just is its activity of thinking – could, like a physical substance, exist in the absence of intentional mental states” is just incoherent. A physicalist might want to raise some other objection to the Cartesian view, but Stoljar’s tu quoque is not open to him.

Now, for the Thomistic or hylemorphic dualist, the soul is to be understood, not as pure thought, but rather as the substantial form of the living human body. And qua form, it is not a complete substance in the first place, much less a material or quasi-material one. (Talk of the soul as an “immaterial substance” is thus for the Thomist at least misleading, though he does hold that the soul subsists beyond the death of the body as an incomplete substance.) Here too, though, talk of interrelated quasi-material parts, “causal pathways,” and the like is completely out of place. But for the Thomist, the Cartesian’s talk of inner “representations” is out of place too; as I have discussed elsewhere (e.g. here and here) the “representationalist” conception of the mind is an essentially modern one that the ancients and medievals generally would have rejected. As a consequence, the ancients and medievals would reject too the essentially modern way of framing the issue of intentionality that I have, for the sake of argument, been following up to now in this post. For instance, if a broadly Aristotelian-Thomistic conception of nature is correct, then natural phenomena really do have intrinsic final causes after all, so that (for example) material efficient causes inherently “point beyond” themselves to their effects. It would follow that a thought’s “pointing beyond” itself cannot be what makes it immaterial; and indeed, that is not the sort of argument the ancients and medievals gave for the mind’s immateriality. (Nor did they argue from “qualia” – that too, as I have noted many times before, is a very modern sort of argument for dualism, and presupposes a mechanistic approach to nature.) The ancients and medievals focused instead on such features of our thoughts as their universality and determinacy, which they took to be essentially incompatible with thought’s having any material organ. (See here, here, chapter 4 of Aquinas and chapter 7 of Philosophy of Mind.)

But that is a gigantic topic of its own. Suffice it for present purposes to note that with respect to Thomistic dualism no less than the Cartesian version, contemporary physicalists would do well to try better to “know their enemy” before dismissing him.

[For more on this theme, see my posts on Paul Churchland and dualism, here, here, and here.]

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.

Deus ex machina?

One more post related to the “Intelligent Design” theory (ID) versus Aristotelico-Thomism (A-T) controversy and then we’ll be done with it for a while. I have emphasized repeatedly that the central objections A-T has against ID are (a) that ID presupposes a mechanistic conception of the natural world, and (b) that ID applies language both to human designers and to God in a “univocal” rather than “analogous” way (in the sense of “analogous” associated with the Thomistic doctrine of analogy). As I have noted before, ID defender VJ Torley has essentially conceded point (b) (though without seeming to realize that this suffices to put ID at odds with A-T), and those who have taken issue with what I have said seem for the most part not to have challenged it. The attention has focused instead on point (a), the charge of mechanism. Defenders of ID concede that the ID approach is mechanistic, but those among them who claim that ID and A-T are compatible insist that this mechanism is purely “methodological” or held only “for the sake of argument,” in a way that need not offend A-T metaphysical scruples. I have argued that ID and A-T are incompatible even if ID’s mechanism is purely methodological.

Let’s leave that debate aside for the moment, though, and consider why it matters. So what if ID is mechanistic? We can begin our answer to that question by recalling what “mechanism” means in this context. Obviously it has something to do with conceiving of the natural world as a kind of “machine” and of the objects within it, including living things, as lesser “machines” within this larger machine. But that is not the core of the notion, and if all that “mechanism” involved was the view that organisms or other natural objects are in some respects comparable to the things people make insofar as they are composed of intricately arranged parts, etc. there would be no objection to it. As I have repeatedly emphasized, what makes a conception of nature “mechanistic” in the sense objectionable to A-T is that it denies the existence of final causality or teleology as an immanent feature of the natural world. For the mechanist, nothing in the natural order inherently or of its nature “points to” anything else as an end or goal, and nothing is inherently or of its nature “for the sake of” anything else. Accordingly, the mechanist also rejects what the Scholastics called “substantial forms” – immanent natures or essences of things, by virtue of which they have the ends or final causes they do. Mechanists who are also theists hold, accordingly, that any final causality, teleology, essences or natures that exist in the world are extrinsic to it, imposed from outside in a fashion comparable to the way the function of serving as a mousetrap is imposed by an artificer on bits of wood and metal that have no inherent tendency to kill mice specifically. This is the view of thinkers like Newton, Boyle, Paley, and other modern defenders of the “design argument” for the existence of God. By contrast, mechanists who are naturalists or atheists deny that there is any genuine teleology in the natural world at all, of either the intrinsic or extrinsic sort.

Note that this is not my own idiosyncratic definition of what a “mechanistic” conception of nature amounts to. To be sure, the early modern thinkers who put mechanism at the center of Western thought often had other things in mind as well – such as the now-discredited notion that all causality could be reduced to a crude “push-pull” contact model – but it is widely agreed that the core of their position, and the part that has survived to the present day, is the rejection of substantial forms and immanent final causes. Philosopher of science David Hull says that “historically, explanations were designated as mechanistic to indicate that they included no reference to final causes or vital forces. In this weak sense, all present-day scientific explanations are mechanistic” (from the article on “Mechanistic explanation” in The Cambridge Dictionary of Philosophy). Philosopher of religion William Hasker holds that “mechanistic causation and mechanistic explanation are fundamentally nonteleological” and that “it was the expulsion of final causes from physics by Descartes and Galileo that marked what was perhaps the most decisive break between ancient and modern natural science” (The Emergent Self, pp. 63 and 64, emphasis in original). Philosopher of mind Tim Crane writes that “in the seventeenth century… the Aristotelian method of explanation – in terms of final ends and ‘natures’ – was replaced by a mechanical or mechanistic method of explanation… To put it very roughly, we can say that, according to the mechanical world picture, things do what they do not because they are trying to reach their natural place or final end, or because they are obeying the will of God, but, rather, because they are caused to move in certain ways in accordance with the laws of nature” (The Mechanical Mind, Second edition, p. 3). Historian of philosophy Margaret Osler notes that while it is not quite right to exclude God per se from mechanistic explanation (as Crane does), “most seventeenth-century mechanical philosophers rejected immanent final causes – in the sense of the actualization of forms – [and] accepted an idea of finality as imposed on nature from without… With the mechanical reinterpretation of final causes, the idea of individual natures that possess immanent finality was replaced with the idea of nature as a whole which is the product of the divine artificer. Nature became a work of art” (“From Immanent Natures to Nature as Artifice: The Reinterpretation of Final Causes in Seventeenth Century Natural Philosophy,” The Monist vol. 79, no. 3 (July 1996), pp. 389-90).

Now, the A-T philosopher would strongly object to the suggestion that science per se is mechanistic in this sense. The truth is that mechanism is not an empirical discovery at all, but rather a philosophical or methodological preference that has been imposed on modern scientific inquiry by fiat; and the actual empirical findings of modern science are all perfectly compatible with an A-T philosophy of nature. But the authors just quoted are all correct to hold that it is the rejection of final causes and substantial forms that is definitive of mechanism, and that mechanism in this sense is commonly (if mistakenly) regarded as essential to science.

In any event, and as Osler’s remarks indicate, it is in light of this rejection of Aristotelian formal and final causes that the significance of the modern tendency to think of the world as a “machine” – in the sense of an intricate mechanical object comparable to a watch or some other artifact – must be understood. As I have said, to call attention merely to the intricacy and interconnectedness of the parts of organisms and other natural phenomena is by itself unobjectionable. The problem, for A-T, is to think of these parts as having no more inherent or built-in tendency to function together to fulfill a common end than the parts of a watch or a mousetrap do. It is because theistically-inclined mechanists deny such inherent tendencies no less than naturalists do that they focus on questions of probability; for if there is no inherent tendency of the parts of any natural object to function together as they do in the first place, the only way to show that some particular natural object (a biological organ, say) is not susceptible of a naturalistic explanation would seem to be to argue that it is so complex that it is improbable that the parts could have gotten together in just the way they have via purely natural processes. (When A-T philosophers criticize the arguments of Paley or ID theorists for being probabilistic, then, it is not at bottom the appeal to probabilities per se that they object to, but rather the mechanistic conception of nature that motivates such an appeal in this particular context.)

But again, so what if ID or any other theory is mechanistic in this sense? Part of the answer is, naturally, that A-T regards mechanism as false, which is enough reason to reject any view committed to it. But mechanism is a particularly pernicious metaphysical error. Indeed, it is from an A-T point of view arguably the cardinal error of modern thought, from which all the other moral and philosophical pathologies of modern world derive. I noted in an earlier post that it is in mechanism that the modern philosophical tendency toward reductionism is rooted. And I argue at length in The Last Superstition – especially in chapter 5 – that it is also in mechanism that we find the roots of such so-called “traditional” philosophical problems as the mind-body problem, the problem of personal identity, the problem of induction, the problem of giving rational foundations to morality, the problem of epistemological skepticism, and the problem of free will. (At least the latter three problems admittedly predate the modern mechanistic revolution, but were made particularly intractable by it.) Morality and even science itself become unintelligible when one attempts to interpret them in a mechanistic context. As W. T. Stace once wrote, the moderns’ abandonment of final causes was “the greatest revolution in human history, far outweighing in importance any of the political revolutions whose thunder has reverberated through the world,” and in its conception of the natural world as inherently “purposeless, senseless, meaningless” lay “the ruin of moral principles and indeed of all values” (“Man Against Darkness,” The Atlantic (September 1948)). Stace – who was writing from an empiricist rather than an A-T perspective – also recognized that this revolution was purely philosophical and not grounded in any actual empirical scientific discovery. And as I noted in another earlier post, other thinkers outside the A-T orbit (such as Alfred North Whitehead and E. A. Burtt) have also acknowledged the philosophical rather than scientific foundations of the mechanistic revolution, and noted its philosophically problematic implications for the science in whose name mechanists have defended their revolution.

More to the present point, though, is that mechanism is simply incompatible with classical theism – the conception of God historically central both to Christian orthodoxy and to classical philosophical theology, and defended by such thinkers as Athanasius, Augustine, Anselm, Aquinas, and (outside the Christian context) by Maimonides, Avicenna, and others. At the core of classical theism is the doctrine of divine simplicity (discussed in this earlier post) according to which there is in God no composition whatsoever. He is not “made up” of either physical or metaphysical parts, the way everything else that exists is – of form and matter, say, or act and potency, or essence and existence. Rather, he just is “pure act” and subsistent existence. He is not “a being” alongside other beings, but rather Being Itself. Also central to classical theism is the notion that the world of created, contingent things could not continue in existence even for an instant were God not continuously preserving it in being. These doctrines are linked. It is because everything in the created order is composite that it must be “held together” in being by something outside it; and it is because God alone is simple or non-composite that He alone can be that which preserves everything else in being in this way.

Now, for A-T, the Aristotelian distinction between act and potency is crucial to understanding divine simplicity, divine conservation, and the connection between them. The essence of a contingent thing (and thus the contingent thing itself) is merely potential or “in potency” until that essence is actualized through being conjoined to an “act of existence.” Matter is merely potential unless conjoined to and actualized by form. In general, potency cannot exist on its own but only when conjoined to actuality. But only that which is Pure Act can possibly end any regress of “actualizers,” precisely because it is simple and has no parts whose conjunction needs to be actualized. Thus the world of composite things could not exist for an instant unless that which is purely actual and absolutely simple were continually holding it together. (As usual, see The Last Superstition and Aquinas for the full story.)

As I have noted before, the act/potency distinction and the notion of final causality are intimately related: A potency or potential is a potency for some act or actuality, toward which it points as an end; and to have an end is to be in potency towards it. It is no accident, then, that when the moderns abandoned final causality for mechanism, the act/potency distinction was abandoned as well. And it is no accident either that the world came to seem like a “machine,” not only in the sense of a kind of artifact cobbled together from parts having no inherent tendency to function toward a common end, but also in the sense of being the sort of thing that might in principle continue to exist even in the absence of a “machinist.” The doctrine of divine conservation gave way to deism, and deism in turn to atheism.

Keep in mind that for Aristotle and the Scholastic tradition influenced by him, the act/potency distinction is crucial to avoiding the extremes represented by Parmenides and Heraclitus, on either of which science becomes impossible. For Parmenides, change is illusion, and thus so too is the world of our experience, on which any empirical science would need to base its findings. For Heraclitus, permanence is the illusion and there is nothing that can unite the deliverances of experience into an orderly scientific system. Aristotle argued, contra Parmenides, that change is possible because in between being and absolute non-being – the only two categories recognized by Parmenides – there is potency or potentiality. But (contra Heraclitus) permanence is also possible, because within the flux of experience emphasized by Heraclitus there are unchanging forms or essences which matter must take on if it is to be actualized at all. It is because these actualizing forms are universal, common to the myriad individuals which instantiate them, and because they persist even as the individual things come and go, that science is possible. For it is the unchanging and universal forms or natures of things that form the proper subject matter of scientific investigation.

Now, the ancient atomists sought to avoid the Parmenidean and Heraclitean extremes in another way. For them, the world of our experience is indeed the flux Heraclitus said it was, but only because underlying it is a world of unobservable unchanging and indestructible (and in that sense “Parmenidean”) elements – the atoms, interacting according to patterns of efficient causation and devoid of any inherent teleology or final causality. But there is nothing further to be said in explanation of the atoms themselves. Limited as the various atoms are to their particular shapes, sizes, positions in space, etc., they cannot intelligibly be said to be purely actual, simple, or in any other way comparable to (and as “self-explanatory” as) the God of classical theism. Nor, devoid as they are of final causality, do they necessarily point beyond themselves to anything else. Accordingly, they constitute the proverbial “brute fact.” Instead of truly avoiding the Parmenidean and Heraclitean extremes, then, the atomists essentially embraced both of them at once: Like Parmenides, they held that the world of our experience is illusory; in reality there is “nothing but” the atoms. And like Heraclitus, they make the world ultimately unintelligible.

But the atomists were the original mechanists, and their modern successors simply repeat their errors. As I have noted in several earlier posts and have argued at length in The Last Superstition and Aquinas, to reject immanent final and formal causes is to make efficient causality unintelligible as well. For if nothing of its nature “points beyond itself” to anything else, then causes and effects become “loose and separate”; any effect or none might in principle follow upon any cause. This not only paves the way for the paradoxes of Hume, but undermines the possibility of showing how the very fact of efficient causation as such – that is to say, of potency being actualized – presupposes a sustaining, purely actual Uncaused Cause. The metaphysically necessary connection between the world and God is broken; in principle the world could exist and operate just as it does apart from God.

There are of course still questions about how the elements of the world machine (whether we think of these elements as Democritean atoms or in more contemporary terms) come to form more or less complex structures. But the weighing of probabilities vis-à-vis whether this or that structure could have come about through known natural processes can never get you one inch closer to the God of classical theism, because that God has already been ruled out the moment it is conceded that the machine might at least in principle have existed without Him. This remains so even if one’s mechanism is adopted only “for the sake of argument.” Making a case for the God of classical theism on a mechanistic basis even arguendo is like saying “Let’s concede just for the sake of argument that whoever murdered Nicole Brown Simpson and Ron Goldman could not have been a man. Now, let me show you why it is probable, given that assumption, that O. J. Simpson was the killer…” The procedure is absurd, because the opening concession has already eliminated the desired conclusion from the running.

But couldn’t one argue that the elements themselves must have come from God? Yes, but not in a “mechanistic” way. For if one affirms of these elements something like an act/potency composition, then one will indeed get to God, but (since such a composition entails final causality) only because one has implicitly abandoned mechanism. But if one insists on denying of the elements any kind of immanent final causality, then one will thereby implicitly be denying of them any sort of potency that needs to be actualized by something outside them. And in that case, the elements will not be necessarily sustained in being by God. Thus, whatever one appeals to in order to explain them could never be the God of classical theism, but only some idolatrous ersatz. Similarly, the God of classical theism is Being Itself, and nothing could exist – that is to say, have being – even for an instant, even in principle, without participating in Being Itself (whether “participation” is understood in Neo-Platonic terms or in the Aristotelianized terms of Aquinas’s Fourth Way). To “weigh the probabilities” that the elements of a mechanistic universe might themselves have a cause is thus implicitly to rule out the God of classical theism as the cause one is arguing for, since whether a thing participates in Being Itself cannot intelligibly be said to be a matter of probability, any more than whether a geometrical theorem follows from certain axioms is a matter of probability.

As Kant famously held, the “physico-theological” or “design” argument for God’s existence really doesn’t get you to God at all, but only to a grand but finite cosmic architect – something like the Ralph Richardson Supreme Being character from Time Bandits, as I pointed out in a previous post. The same is true of any argument that proceeds, as Paley and his successors have done, by portraying God as a tinkerer who cobbles together a mechanistic universe. And the point, as I cannot repeat too often, is not that such arguments don’t get you all the way to the God of classical theism, but that they get you positively away from the God of classical theism. You can get a god from a machine, but never the God.