The interaction problem, Part III

In a couple of previous posts (here and here) we have examined the famous “interaction problem” facing Cartesian dualism and its origins in the impoverished conception of causation the early modern philosophers put in place of the Aristotelian-Scholastic conception. But as Bill Vallicella rightly notes, whatever we think of the interaction problem and of Cartesian dualism’s ability to deal with it, it cannot be regarded as a reason for preferring materialism to dualism. For materialism faces an interaction problem of its own.

Part of the problem is that even if we identify mental events and physical events, mental properties seem to have no causal relevance. Suppose a sensation of pain is identical with such-and-such a neural firing pattern. The way it causes you to moan and to nurse the damaged body part is by triggering further neural processes which result in the flexing of the relevant muscles. In that case, though, it is the electrochemical properties alone that are doing the causal work, and the distinctively mental aspect – the experienced phenomenal character of the pain itself – seems epiphenomenal. This is called the “mental causation problem” and it is the aspect of the interaction problem for materialism that Bill focuses on. It arises in different ways for different varieties of materialism. (It threatens Donald Davidson’s anomalous monism, for example, because of his principle of the anomalism of the mental.)

But this isn’t the only way the interaction problem arises for materialism. It arises also because the mechanistic conception of the natural world makes body-body interaction as mysterious as mind-body interaction. And again, it does so because of the impoverished conception of causation the moderns put in place of the older Aristotelian-Scholastic conception.

The Aristotelian-Scholastic account of causation was rich in theoretical subtleties and carefully worked out distinctions. It included, not only the famous doctrine of the four causes – formal, material, efficient, and final – but also the act/potency distinction, the notion that causes and effects can sometimes be simultaneous, the distinction between causal series ordered per se and causal series ordered per accidens, the distinction between primary and secondary causes, the idea that causation involves the cause communicating something to its effect, an emphasis on substances rather than accidents or events as true causes, and so forth. But as Kenneth Clatterbaugh notes in The Causation Debate in Modern Philosophy 1637-1739, in the century or so between the time of Descartes’ work on the subject and that of Hume, virtually all of the characteristic theses of the Aristotelian-Scholastic account of causation were gradually abandoned. Of the four causes, only efficient causation was left, and in a radically modified form. Substances and their inherent causal powers were abandoned and causation was regarded instead as a relationship between events. Nothing was taken to be communicated from cause to effect and in principle anything might follow upon anything else.

What resulted, naturally, were the skeptical puzzles of Hume. The notion of causation as an objective feature of the world became problematic at best and unintelligible at worst. As I argue at length in The Last Superstition and Aquinas, and have discussed more briefly in earlier posts (e.g. here and here), this was inevitable given the abandonment of final causality. If there is nothing in a cause that inherently “points to” or is “directed at” the generation of a certain effect or range of effects, there is ultimately no way to make sense of the fact that it does indeed generate just that effect or effects.

Hence the fact that a material cause brings about just the material effect or effects it does becomes no less mysterious on the modern, mechanistic account of nature than mind-body interaction does. This is the reason bizarre theories like occasionalism and pre-established harmony had the cachet they did among some of the early moderns. The motivation was not, as is sometimes supposed, to find a way to salvage mind-body dualism. It was rather to find a way to deal with the fact that any causation at all in the natural order – even that between material bodies – seemed impossible given the new conception of nature.

But haven’t many contemporary philosophers tried to solve the puzzles about causation raised by the early modern philosophers, especially Hume? Indeed they have, but as I have shown in TLS and Aquinas, when they have attempted to provide a realist account of causation, the tendency has been to appeal to notions – inherent causal powers, “physical intentionality,” dispositions, and so forth – which essentially involve a return to something like an Aristotelian conception of nature. Clatterbaugh cites the example of Wesley Salmon, who in Four Decades of Scientific Explanation argues that genuine causal processes involve a “transmission” of “information,” and even of “structure,” from cause to effect. Like some of the other contemporary writers I’ve cited before (Armstrong, Molnar, et al.), Salmon does not realize that he sounds like a Scholastic.

The “interaction problem,” then, is not a problem for Cartesian dualism per se but for modern metaphysical positions in general, including materialism. Accordingly, its existence has no tendency whatsoever to provide an argument in favor of materialism over dualism. What it does provide is an argument in favor of a broadly Aristotelian-Scholastic metaphysics over any modern, mechanistic would-be replacement.

Churchland on dualism, Part III

To conclude our look at Paul Churchland’s critical discussion of dualism in his textbook Matter and Consciousness, let’s consider the arguments he presents against dualism. There are four of them, and they can be summarized as follows:

1. The argument from Ockham’s razor: Postulating two basic kinds of substance, material and immaterial, needlessly complicates our ontology if mental phenomena can be adequately explained in terms of material substance alone. That they can be so explained is indicated by the next two arguments:

2. The argument from the explanatory impotence of dualism: Materialist explanations can appeal to the many details of the brain’s structure and function revealed by modern neuroscience, while dualists have yet to provide a comparable account of the structure and function of immaterial substance.

3. The argument from the neural dependence of all known mental phenomena: As both everyday experience and neuroscientific research show, reasoning, emotion, and consciousness are all very closely correlated with various processes in the brain, which is not what we would expect if these mental phenomena were associated with an immaterial substance.

4. The argument from evolutionary history: The evolutionary process that gave rise to the human species proceeded via purely material mechanisms from a purely material starting point, so that the end result must itself be purely material.

Churchland acknowledges that none of these arguments is by itself absolutely conclusive. But he does think the third one “comes close to being an outright refutation of (substance) dualism,” and he clearly believes that in tandem the arguments consign dualism to the dustbin for all practical purposes. No doubt most materialists would agree with him. But in fact these arguments have, I maintain, no force at all against dualism. None. Dualism may or may not in fact be true – obviously I think it is true, but that is another issue. The point is that, even if it were false, these arguments have no tendency to show that it is.

How can I say that? Easy. Keep in mind first of all that, as I have emphasized in the earlier posts in this series, the chief proponents of dualism historically have not defended their position as an “explanatory hypothesis” put forward as the “best explanation” of the “empirical data.” That just isn’t what they are up to, any more than geometers or logicians are. They are attempting instead to provide a strict demonstration of the immateriality of the mind, to show that it is metaphysically and conceptually impossible for the mind to be something material. Their attempts may or may not succeed – again, that is another question. But that is what they are trying to do, and thus it simply misses the point to evaluate their arguments the way one might evaluate an empirical hypothesis. When Andrew Wiles first claimed – correctly, as it turned out – to have proven Fermat’s Last Theorem, it would have been ridiculous to evaluate his purported proof by asking whether it best accounts for the empirical evidence, or is the “best explanation” among all the alternatives, or comports with Ockham’s razor. Anyone who asked such questions would simply be making a category mistake, and showing himself to be uninformed about the nature of mathematical reasoning. It is equally ridiculous, equally uninformed, equally a category mistake, to respond to Plato’s affinity argument, or Aristotle’s and Aquinas’s argument from the nature of knowledge, or Descartes’ clear and distinct perception argument, or the Cartesian-Leibnizian-Kantian unity of consciousness argument, or Swinburne’s or Hart’s modal arguments, or James Ross’s argument from the indeterminacy of the physical, by asking such questions. As with a purported mathematical demonstration, one can reasonably attempt to show that one or more of the premises of such metaphysical arguments are false, or that the conclusion does not follow. But doing so will not involve the sorts of considerations one might bring to bear on the evaluation of a hypothesis in chemistry or biology.

Of course, Churchland, committed as he is to a Quinean form of scientism, thinks that all good theories must in some sense be empirical scientific theories. He rejects the traditional conception of metaphysics as a rational field of study distinct from and more fundamental than physics, chemistry, biology, and the like, and would deny that there is any such thing as sound metaphysical reasoning that is not in some way a mere extension of empirical hypothesis formation. But he cannot simply assume all of this in the present context without begging the question, because this sort of scientism is precisely (part of) what the dualist denies. (As we have seen in earlier posts on naturalism, this kind of circular reasoning is absolutely rife in naturalist thinking.)

It is obvious, then, why Churchland’s first two arguments have no force, for they simply misconstrue the nature of the case for dualism. If any of the dualist arguments just mentioned works, then the immateriality of the mind will have been demonstrated, and asking “But do we really need to postulate immaterial substance?” or “How much can we really know about such substances?” would not be to the point. For we would not in that case be hypothetically “postulating” anything in the first place, but directly establishing its existence; and its existence will have been no less established even if we could not say much about its nature.

But this brings us to an additional problem with Churchland’s second argument, which further underlines just how embarrassingly uninformed he is about what dualists have actually said. In developing his “explanatory impotence” objection, Churchland complains that dualists have told us very little about the nature of “spiritual matter” or the “internal constitution of mind-stuff,” about the “nonmaterial elements that make it up” and the “laws that govern their behavior.” This is, for anyone familiar with the thought of a Plato, an Aquinas, a Descartes, or a Leibniz, simply cringe-making. The soul is not taken by these writers to be “made up” out of anything, precisely because it is metaphysically simple or non-composite. It is not a kind of “stuff,” it is not made out of “spiritual matter” (whatever that is), and it is not “constituted” out of “elements” which are related by “laws.” Nor is this some incidental or little-known aspect of their position – it is absolutely central to the traditional philosophical understanding of the soul. As is so often the case with naturalistic criticisms of dualism, theism, etc., Churchland’s argument is directed at a breathtakingly crude straw man.

This appalling ignorance of the actual views of dualists manifests itself again in Churchland’s third argument. Churchland himself admits that this argument has no effect against property dualism, since property dualism itself takes the brain to be the seat of mental phenomena. But he fails to see that it has no effect against the other main varieties of dualism either, given what they actually say about the relationship between the mind and the brain.

For starters, let’s take Aristotelian-Thomistic (A-T) hylemorphic dualism. The A-T view is that the intellect is immaterial, but that sensation and imagination are not. Hence it is no surprise at all that neuroscience has discovered various neural correlates of mental imagery and the varieties of perceptual experience. Moreover, A-T holds that though intellect is immaterial, its operation requires the presence of the images or “phantasms” of the imagination. Hence it is no surprise that neural damage can affect even the functioning of the intellect. Most importantly, the soul, of which intellect, sensation, and imagination are all powers, is not a complete substance in its own right in the first place, but rather the form of the body. The way intellectual and volitional activity relates to a particular human action is, accordingly, not to be understood on the model of billiard ball causation, but rather as the formal-cum-final causal side of a single event of which the relevant physiological processes are the material-cum-efficient causal side. That alterations to the body have mental consequences is thus no more surprising than the fact that altering the chalk marks that make up a triangle drawn on a chalkboard affects how well the marks instantiate the form of triangularity. It is important to emphasize that none of this involves any sort of retreat from some stronger form of dualism, as a way of accommodating the discoveries of contemporary neuroscience; it is what A-T has always said about the relationship between soul and body. There is absolutely nothing in modern neuroscience that need trouble the A-T hylemorphic dualist in the slightest.

What about the Cartesian dualist? Don’t the differences between Descartes’ views and those of his Scholastic predecessors make him vulnerable to the findings of neuroscience in a way the latter are not? No, they don’t. For one thing, and as I have noted in an earlier post, Descartes’ views on this subject were not in fact quite as different from those of his predecessors as is often supposed. For example, Descartes’ view appears to have been that it is the intellect, specifically, which is to be identified with the ego he thinks is capable of existing apart from the body. Sensations, emotions, and the like he regarded, not as purely mental phenomena, but rather as hybrid properties which can be predicated only of the soul-body composite, and not the soul alone. Hence even on Descartes’ view it is not at all surprising that neuroscience has discovered all sorts of correlations between various aspects of perceptual experience and various emotional states on the one hand, and various processes in the brain on the other.

Now what is true is that the Cartesian has a difficulty explaining mind-body interaction that the A-T view does not have, as I have discussed here and here. And the reason is that Descartes rejected the notion that the soul is the formal cause of the body. That is an enormously consequential difference between the two views. But it has nothing to do with the specific question about whether a dualist need be troubled by the discovery of detailed correlations between mental phenomena and neural phenomena, which is what is at issue in the argument of Churchland’s under consideration. In particular, even the Cartesian need not be troubled by the fact that intellectual activity too (and not just sensation, emotion, and the like) can be dramatically affected by changes to the brain.

Why not? For one thing, as Churchland himself admits, the Cartesian regards the brain as a “mediator” between the soul and the rest of the body, so that we should expect that damage to this mediator will prevent the intellect from receiving the information it derives from the body and from controlling bodily behavior as well as it normally would.

But there is a deeper consideration. Consider the following analogy: A typed, written, or spoken token of the word “bark,” considered merely as a material object, has all sorts of complex physical properties, and those physical properties are highly relevant to its status as a word, as a bearer of linguistic meaning. Alter the physical properties of the token too radically, and it can no longer convey the meaning it once did. For example, if the ink should smear, the sound be muffled, or the power source to a word processor be cut off, the word will disappear, or might at least become so distorted that it becomes unintelligible. It would be absurd, though, for someone to suggest that these facts lend any support whatsoever to the claim that a word token qua word token is exhausted by its physical properties. It clearly is not. It is, for example, indeterminate from the physical properties alone whether the “bark” in question is the bark of a dog or the bark of a tree. Indeed, since the fact that the relevant sounds and shapes are associated with a certain meaning is entirely contingent, an accident of the history of the English language, it is indeterminate from the physical properties alone whether the word has any meaning at all. In short, the physical properties are a necessary condition for any particular physical object’s counting as a word token, but they are not a sufficient condition. And piling up bits of physicochemical knowledge about word tokens cannot possibly change this fact in the slightest, for it is a conceptual point about the nature of words, not an empirical point about what the latest research in phonetics (or whatever) has turned up.

In the same way, the dualist claims to be making a conceptual point about the relationship between mind and body, one to which neuroscientific research, important and interesting as it is in itself, is irrelevant. The existence of such-and-such physiological phenomena may well be a necessary condition for the existence of intentional human actions, intelligible speech, and so forth, but it is not and cannot be a sufficient condition. And that remains true whether we are interpreting dualism in A-T terms or in Cartesian terms. A-T regards the soul as the formal cause of a single substance of which the matter of the body is the material cause. Cartesians regard mind and matter as two distinct substances. Either way, there is not, and in principle cannot be, anything distinctively mental in matter as such, any more than a word token, considered merely as an arrangement of ink marks or a pattern of sound waves, has any meaning on its own. Or at least, there cannot be if dualism is correct. No amount of neuroscientific evidence can undermine this judgment, because what is at issue is whether any purely material phenomena at all, neurological or otherwise, can in principle be mental.

“But doesn’t that make dualism unfalsifiable?” If “unfalsifiable” means “not subject to rational evaluation and criticism,” then no, of course it isn’t unfalsifiable. Metaphysical arguments, like mathematical arguments, are perfectly susceptible of rational analysis and refutation, even if, like mathematical arguments, such analysis does not involve the weighing of probabilities, the comparison of alternative empirical hypotheses, etc. If “unfalsifiable” means instead “not subject to refutation via empirical scientific research,” then yes, dualism is unfalsifiable in that sense. But so is mathematics, and yet that doesn’t detract from its status as a rational field of investigation. Again, if the materialist wants to insist that all rational inquiry must ultimately be a kind of empirical scientific inquiry, he is welcome to make the case, but he cannot simply assume the truth of scientism when criticizing the dualist, otherwise he will simply be begging the question.

And that brings us, finally, to the fourth of Churchland’s arguments, the argument from evolution. Here again we have an argument that is entirely without force, and the main reason should be obvious from what has just been said: Dualism is a metaphysical theory, not an empirical hypothesis, and thus it is not the sort of thing that could be refuted by empirical biological findings any more than by neuroscientific ones.

But there is more to be said. Churchland’s fourth argument is also question-begging. For whether Darwinian evolution – which is supposed to be a purely materialist theory – is in fact a complete explanation of human nature depends on whether human nature is entirely material. And of course, the dualist’s claim is precisely that human beings are not and cannot be purely material, in which case no purely materialist theory could possibly provide a complete explanation of human nature. Hence it is no good to merely to assert, as an argument against dualism, that Darwinism has already explained human nature in materialist terms. That simply assumes the falsity of dualism without proving it.

Nor is it any good to stamp one’s feet and insist that if Darwinism entails materialism, then we had all better be materialists. Because here’s a newsflash: If Darwinism entailed that 2 + 2 = 5, what that would show is, not that 2 + 2 = 5, but that Darwinism is false, or at least needs to be seriously modified. Similarly, if Darwinism really does entail materialism, but the arguments of an Aquinas, a Descartes, or a James Ross show that materialism is false, then so much the worse for Darwinism. It had better adapt itself to the metaphysical facts, or be selected out. Like so many other naturalists, Churchland waves the “evolution” talisman as if it sufficed to shut off all debate, assuring us that in light of Darwinism we “are creatures of matter” and “should learn to live with that fact.” But this is sheer, question-begging bluff, not serious philosophical argument.

We have seen, then, over the course of these three posts, that Churchland’s treatment of dualism in Matter and Consciousness, though purporting to be a balanced summary, is in fact almost completely worthless both as a guide to what dualists have actually said and as a critique of dualism. And this is a textbook! And a widely used one, which has long been in print – it was one of the books I was taught out of as an undergraduate, and (I am ashamed to say) as a teacher I once used it myself. It took me many years to see just how bad it is. Most students who have read it probably have no idea, and never will.

But that’s how bad ideas spread: By ignorance and intellectual dishonesty smugly masquerading as expertise. Here, as with the debate over theism, the naturalistic skeptic can maintain the illusion of rational superiority only to the extent that he and his readers remain ignorant of what the great thinkers of the past have actually said. For to paraphrase Cardinal Newman, to be deep in history is to cease to be a naturalist.

Churchland on dualism, Part II

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Churchland on dualism, Part I

We have been hammering away at eliminative materialism (EM) in a series of posts. If EM proponents fail to make their own position plausible or even coherent, how do they fare as critics of alternative views? Not much better. Let’s look at Paul Churchland’s treatment of dualism in (the 1988 revised edition of) his textbook Matter and Consciousness. (There’s the book’s cover at left. It’s better than the book itself, which I guess confirms the old adage. I considered using this illustration, but it seemed a bit impolite.)

There are two main problems with Churchland’s discussion. First, his summary of the case for dualism is no good. Second, his arguments against dualism are no good either. In this post we’ll look at the first problem and in a second post I’ll address the second.

What are the main arguments for dualism? Churchland identifies four; he calls them the argument from religion, the argument from introspection, the argument from irreducibility, and the argument from parapsychology. To anyone familiar with the philosophical literature on dualism, this list cannot fail to seem very odd.

One problem with it is that it includes two arguments – the “argument from religion” and the “argument from parapsychology” – that dualist philosophers actually put little or no emphasis on. As Churchland presents the “argument from religion,” it amounts to little more than the claim that “Dualism must be true, because my religion says it is.” He cites no philosophers as actually having given this argument, no doubt because there aren’t any. (Yes, a philosopher who happens to believe on independent grounds that his religion is true and that it entails dualism might present that as an argument for dualism to someone who already agrees with its premises. But no dualist philosopher I can think of has ever pretended that such an argument would be a good stand-alone argument for convincing either an irreligious materialist or even someone whose attitude toward either religion or dualism is noncommittal.)

The “argument from parapsychology” no doubt does have some defenders; certainly there are serious philosophers who have taken the subject of alleged paranormal phenomena seriously either in a sympathetic way (e.g. C. D. Broad and, in recent years, Stephen Braude) or in a critical spirit (e.g. Antony Flew). But this subject does not in fact play much of a role in contemporary debates over dualism, and even those philosophers who believe that at least some purported paranormal phenomena cannot plausibly be explained away in terms of existing scientific theory (e.g. Braude) do not necessarily put such claims forward, primarily or at all, as grounds for accepting dualism.

It is in any event a mistake to think that dualism is intended as a kind of scientific hypothesis put forward as the “best explanation” of the empirical evidence, parapsychological or otherwise. The central arguments for dualism have always been attempts at metaphysical demonstration, intended to show conclusively that whatever the mind is, it cannot even in principle be material. And this brings us to the most glaring fault with Churchland’s list: He simply ignores these key arguments entirely. For example, though he purports to summarize Descartes’ own reasons for endorsing dualism, and rightly notes that Descartes thought that certain key mental phenomena are irreducible to material phenomena, he fails even to mention the two arguments Descartes put the most emphasis on: the clear and distinct ideas argument (these days often called the conceivability argument or the modal argument), and the indivisibility argument (which is related to what is often called the unity of consciousness argument). The first argument (which I have discussed in a previous post) holds that since – the argument claims – it is metaphysically possible for mind to exist apart from anything material, it cannot be material. The second holds that the mind has a kind of unity or indivisibility-in-principle that nothing material can have. (Variations on this basic idea were also defended by the likes of Leibniz and Kant.)

It isn’t like these arguments are not well known. Nor are they mere historical relics; they have defenders to this day. (For those who are interested, I discuss them in detail in my book Philosophy of Mind.) The modal argument in particular received renewed attention in the wake of Kripke’s Naming and Necessity, and thus in the years leading up to the publication of Churchland’s book. It was defended by Richard Swinburne in The Evolution of the Soul, which appeared in 1986 – two years before Churchland’s revised edition – and by W. D. Hart in The Engines of the Soul, which itself came out in 1988. (Charles Taliaferro is another philosopher who has defended it in the years since, in his book Consciousness and the Mind of God.)

Churchland also ignores – as, in fairness, almost all contemporary philosophers of mind do – what early modern writers like Malebranche regarded as the central proof of dualism, viz. that dualism follows from the very mechanistic conception of matter Cartesians and materialists hold in common. For if color, odor, taste, sound, etc., as common sense understands them, do not exist in matter itself but only in our perceptual experience of matter, then those experiences cannot be material. (I have discussed this argument in previous posts as well, e.g. here and here.)

What is in fact the chief argument for dualism, at least from the point of view of the classical (Platonic-Aristotelian-Thomistic-Scholastic) traditions in philosophy, concerns, not sensory qualities or “qualia,” but rather our capacity for abstract thought. For concepts, and our thoughts about them, are universal in a way nothing material can be, and (sometimes, anyway) determinate, precise, or unambiguous in a way nothing material can be. (I have discussed this sort of argument too in many earlier posts, e.g. here and here.) While this line of argument has also been largely ignored by contemporary academic philosophers of mind, it was defended by Mortimer Adler in the years leading up to the publication of Churchland’s book, and by 20th century Thomist writers generally. Needless to say, Churchland ignores it as well.

So, while Churchland pretends to be summing up “some of the main considerations” usually given in support of dualism, he completely ignores the arguments the most prominent dualist philosophers actually regarded as the most important, and includes arguments that dualists do not typically make use of – arguments that are either clearly feeble (the “argument from religion,” as Churchland presents it) or which rest on premises which are as controversial as dualism itself is (the “argument from parapsychology”). The rhetorical effect is obvious: The unwary reader, who assumes that a textbook will give him an accurate summary of what each side has to say, is bound to come away with a completely distorted conception of the case for dualism. In particular, he is bound to think it far weaker than it actually is.

I am not claiming that Churchland is knowingly perpetrating what looks like a pretty sleazy rhetorical tactic. I think he is, like most materialists, simply ignorant of what most dualists have actually said. He no doubt thinks he knows enough about what they say to be justified in concluding that their position is not worth looking into any further than he already has. He is wrong, but will never know that he is, because he has gotten himself onto the sort of merry-go-round that (as we have seen in recent posts) naturalists seem to have so much difficulty keeping off of: “I know that dualism is too silly to investigate any further because of how bad the arguments for it are; and I know that I must be understanding those arguments correctly because dualism is obviously just too silly to be worth investigating any further.”

The thing is, books like Matter and Consciousness contribute to the formation of the same mindset in others. As generation after generation of philosophy students are taught out of such books, the conclusion that dualism is intellectually disreputable comes to seem something that “everyone knows.” In fact, what “everyone knows” is nothing more than a bunch of straw men and circular arguments, bounced around the materialist echo chamber long enough that no one can hear anything else. (This is, of course, exactly parallel to what most atheist philosophers “know” about the classical arguments for God’s existence, as I have noted here, here, and here. The hegemony of atheism and materialism crucially depend on a stubborn and studied ignorance of what theists and dualists have actually said.)

Having said all that, Churchland is at least correct to say that what he calls the "argument from introspection" and the "argument from irreducibility" are prominent arguments for dualism. Unfortunately, what he says about these arguments is no good either. We’ll see why in part II.

Lycan on eliminative materialism

Take a look at William Lycan’s essay “A Particularly Compelling Refutation of Eliminative Materialism.” (Hat tip to Bill Vallicella.) It is a very good refutation indeed, and Aristotelian in spirit, though Lycan is himself a naturalist and not an Aristotelian.

I do have some minor complaints. Lycan’s criticism of eliminative materialism (EM) does not claim that EM is self-defeating, which is fine. But he also claims that such criticisms are “hopeless.” Why? He doesn’t tell us. Hopefully it isn’t merely because the proponent of EM needn’t be committed to “believing there are no beliefs,” for as we saw earlier (here and here), the incoherence problem for EM goes far deeper than that. And hopefully it isn’t because he thinks no prominent philosophical theory could plausibly be blatantly incoherent, for as we also saw earlier, that is indeed sometimes the case (e.g. the verificationist criterion of meaning).

Furthermore, while I agree with Lycan that metaphysics cannot overthrow common sense, that is emphatically not because metaphysics rests on mere “intuitions.” That contemporary academic philosophers are always appealing to what their “intuitions” tell them about this or that does not reflect anything more than the pathologies of contemporary academic philosophy, and tells us nothing about the nature of metaphysical inquiry as such. (You won’t find Aristotle or Aquinas appealing to their “intuitions.”)

But those are quibbles. After you read Lycan’s paper, take a look at his essay “Giving Dualism Its Due.” As these papers show, Lycan is no ideologue. He is the sort of naturalist dualists and other non-naturalists need to take seriously.

Petersen on naturalism

Over in the combox at What’s Wrong with the World, reader Bobcat points us in the direction of Steve Petersen’s paper “Naturalism as a coherent ism.” Petersen is a naturalist but acknowledges that most presentations of naturalism are open to the charge of incoherence – that their way of making the claim that natural science is the only genuine path to knowledge fails to explain how this claim itself can be judged a scientific claim.

Petersen’s solution is as follows: Let’s think of naturalism as a commitment to the methodology of science; let’s think of science as a commitment to the model of inference to the best explanation; and let’s think of explanation as a matter of systematically boiling things down to a minimum number of brute facts. Or in Petersen’s “soundbite form”: “Naturalism is scientism is explanationism is unificationism.” Mathematics, with its axiomatic method, and philosophy, with its methods of conceptual analysis and unification via general principles, would count as “naturalistic” in this sense. Astrology, which posits unexplained relationships between celestial activity and the course of everyday human life, would not. More to the present point, naturalism itself would count as a naturalistic theory in this sense, so that the coherence problem is solved.

The trouble with this is that it makes naturalism completely trivial; in particular, it makes Plato, Aristotle, Plotinus, Aquinas, et al. all “naturalists” committed to “scientism.” Indeed, it makes their views more “naturalistic” and “scientistic” than those of most contemporary self-described “naturalists.” For Neo-Platonic arguments for The One, say, or Aristotelian-Thomistic arguments for an Uncaused Cause who is Actus Purus and ipsum esse subsistens, eliminate brute facts altogether – the ultimate cause of things, on these views, could not possibly have been other than it is – while most contemporary naturalists assume that some brute facts or other are inevitable, and the only question is how many we need to countenance.

Petersen is aware of the problem that his position seems trivial if it entails that philosophical claims collapse into scientific ones, and his solution is to bite the bullet and propose that we accept this expansion of what is allowed to count as scientific. The problem now is that while this might seem plausible if we focus only on the sorts of thinkers Petersen takes as examples of “naturalistic” philosophers in his expanded sense – Hume and Quine – it seems absurd when we consider philosophers like the ones I mentioned.

Petersen also insists that his position is non-trivial insofar as it is incompatible with any conception of “first philosophy” that would let philosophy trump empirical science when there is a conflict between the two. The trouble with this is that it attacks a straw man. No advocate of “first philosophy,” whether in the older, Scholastic understanding of this idea or in the modern Cartesian rationalist sense, believes that philosophy and empirical science can ever truly conflict with one another. It would be nice to have an instance of such a purported conflict, but Petersen does not give us one.

But let us consider, for example, Thomistic arguments for the immateriality of the intellect or Cartesian arguments for immaterial substance. Are these incompatible with any finding of empirical science? They are not, because they are not probabilistic “empirical hypotheses” which have somehow been superseded by later and better “empirical hypotheses.” Rather, they are attempts to demonstrate that the mind cannot even in principle be material, so that the immateriality of thoughts and the like is itself simply part of the data of which any empirical theory must take account. We can argue about whether or not they succeed in showing this, but in the nature of the case they cannot be said to be incompatible with any finding of empirical science, because they have to do with higher-order questions about the data from which such scientific inquiry must begin – questions Peterson himself allows as a legitimate area of philosophical inquiry on his broadened conception of naturalism.

I don’t know if Petersen would claim otherwise, but many other naturalists would, on such grounds as that (a) arguments for dualism involve “positing” something like “ectoplasm” as the most “probable” way of “explaining” human behavioral and psychological phenomena, where these arguments are held to be less compelling than the materialist alternatives, or (b) that natural science has somehow already “shown” that there are no immaterial phenomena. The problem here is that (a) is a complete travesty of what dualist arguments actually say, and (b) is invariably question-begging, and typically committed to the very sort of incoherent naturalism that Petersen rejects.

As it happens, though, Petersen is happy to acknowledge that his position so broad that it will allow even Richard Swinburne’s arguments for God’s existence to count as “naturalistic.” Many would no doubt regard this as a suicidal concession, but it is not. For Swinburne’s arguments are essentially of the family of arguments most famously associated with William Paley – arguments that take for granted a broadly mechanistic conception of nature, conceptualize God in terms used univocally both of him and of us, proceed via probabilistic hypothesis formation, etc. And as I have argued in a couple of recent posts (here and here) a sophisticated naturalist would realize that he has nothing to fear from Paley-style arguments. What naturalists really want to avoid is the God of classical theism, and as I argue in those posts, Paley-style arguments not only don’t get you to, but indeed get you away from, the God of classical theism.

What does get you to classical theism, though, are arguments informed by some variety of classical metaphysics – arguments of the sort given by Aristotelians, Neo-Platonists, Thomists, etc. That’s where the real trouble for Petersen’s position comes in, because it is so broad that it includes even these. And if metaphysical demonstrations of Plato’s Form of the Good, or Aristotle’s Unmoved Mover, or Plotinus’s One, or Aquinas’s ipsum esse subsistens count as “naturalistic,” then Petersen’s “naturalism” isn’t anything close to what contemporary naturalists think of their position as consistent with.

Or to put it another way: If Petersen’s “naturalism” has put him in the same camp with the author of The Last Superstition, then his dissertation adviser has given him some seriously bad career counseling…

Searle, Aquinas, and property dualism

In an addendum to his article “Why I Am Not a Property Dualist,” John Searle suggests that property dualism really entails substance dualism. For it describes mental properties as “arising from” and existing “over and above” the brain, and “these metaphors suggest that… consciousness is something separate from the brain” given that “uncontroversial properties of the brain, like weight, shape, colour, solidity, etc.” are not said to exist in that way. For consciousness to exist “over and above” the brain requires that it be “a separate thing, object, or non-property type of entity.”

Searle’s claim here seems reminiscent in some ways of Aquinas’s argument for the subsistence of the human soul at Summa Theologiae I.75.2:

Therefore the intellectual principle which we call the mind or the intellect has an operation "per se" apart from the body. Now only that which subsists can have an operation "per se." For nothing can operate but what is actual: for which reason we do not say that heat imparts heat, but that what is hot gives heat. We must conclude, therefore, that the human soul, which is called the intellect or the mind, is something incorporeal and subsistent.

Aquinas has argued earlier for the first claim made in this passage, viz. that intellectual operations do not involve a bodily organ. What he saying here is that this claim entails that that which carries out these operations, the human soul, must “subsist” apart from the body; it isn’t a mere accident or attribute of the body. The reason is the Scholastic principle that agere sequitur esse, activity follows upon being. Heat, as a mere accident or attribute, cannot cause something to be hot; rather it is the substance which has the heat that causes something else to be hot. Similarly, an operation which is not carried out by any bodily organ but which – qua operation rather than substance – cannot exist apart from some substance or other, must inhere in something immaterial.

So, when Searle tells us that immaterial mental properties would have to inhere in something immaterial rather than in a material object like the brain, he is saying something which seems to dovetail with Aquinas’s argument.

Still, things are a bit more complicated than that. For one thing, unlike many contemporary property dualists, Aquinas does not regard consciousness (as contemporary philosophers tend to understand “consciousness”) as immaterial. Rather, it is intellectual activity (grasping abstract concepts, reasoning, etc.) that he takes to be immaterial. Second, Aquinas is not only not a property dualist, he is not (contrary to appearances) a substance dualist either, certainly not in the way that sort of view has been understood since Descartes. Rather, he is a hylemorphic dualist. From a Thomistic point of view, substance dualism, property dualism, materialism, idealism, neutral monism, and all other post-Cartesian theories of the mind presuppose a mistaken and muddleheaded conception of both mind and matter – a conception which (among other things) makes it very difficult for contemporary philosophers even to understand the Thomistic view. As when dealing with Aquinas’s position on other specific philosophical questions, the only way properly to understand what he says about the relationship between mind and body is to situate it within his general metaphysics, which presupposes an understanding of the notions of act and potency, form and matter, substance and accident, essence and existence, analogical predication, etc. I set all this out in Aquinas, with chapter 4 devoted to Aquinas’s psychology and how it differs radically from contemporary substance dualism, property dualism, etc.

Now, some further reading, while you wait for your copy of Aquinas to arrive: First, my essay “Why Searle Is a Property Dualist,” which explains why Searle’s own anti-materialist arguments in philosophy of mind do in fact entail property dualism, despite his attempt to avoid this result. Second, check out David Oderberg’s article “Hylemorphic Dualism” for an overview of the Thomistic position. Third, take a look at Alfred Freddoso’s article “Good News, Your Soul Hasn’t Died Quite Yet” for a discussion of some of the differences between the Thomistic view and the standard modern ones (and why Catholics, especially, should be wary of the latter, including modern versions of dualism).

Rosenberg on naturalism

A reader writes to inform me of Alex Rosenberg’s very interesting essay “The Disenchanted Naturalist’s Guide to Reality.” Rosenberg’s thesis? That naturalism entails nihilism; in particular, that it entails denying the existence of objective moral value, of beliefs and desires, of the self, of linguistic meaning, and indeed of meaning or purpose of any sort. All attempts to evade this conclusion, to reconcile naturalism with our common sense understanding of human life, inevitably fail. Naturalism, when consistently worked out, leads to a radical eliminativism. Says my informant: “Why, it sounds shockingly similar to some things you once wrote in a book that was all about sperm, does it not?” Indeed, except that when I said it I was a “religiously inspired bigot,” whereas when Rosenberg says it he gets a respectful link, complete with a fanboyish exclamation point. Odd, no?

Not really. Because in The Last Superstition I argue that the implications in question constitute a reductio ad absurdum of naturalism, whereas Rosenberg (who is himself a naturalist) regards them instead as a set of depressing truths we must learn to live with. As you’ll see from Rosenberg’s combox, not all naturalists agree with him. But naturalist religionists are an ecumenical bunch. They’ll allow you to draw any absurd conclusion you wish from naturalist premises, as long as (naturally enough) you never under any circumstances question the premises themselves.

As TLS argues at length, the position Rosenberg rightly takes to follow from naturalism is not only depressing; it is incoherent. Therefore, naturalism is false. Furthermore (and as I also argue at length in TLS) there are no non-question-begging arguments for naturalism in the first place. Its hegemony over contemporary intellectual life owes entirely to a mixture of philosophical muddleheadedness, ignorance of philosophical history, and anti-religious animus. (Again, see TLS for the details.)

Rosenberg’s essay only bolsters the already ample evidence for these claims. Let’s take them in order:

1. Naturalism is incoherent: Suppose (as I argue in TLS) that Rosenberg is right about what naturalism implies. In that case there are no beliefs or desires, nor is there any such thing as the “original intentionality” or meaning that common sense says thoughts have, and which it takes to be the source of the derived intentionality exhibited by language. But then, Rosenberg rightly concludes, there’s no such thing as “the” real or actual meaning of a work of art, a human action, or indeed of anything else. There is simply no fact of the matter about what anything means. So far so good, and so far what Rosenberg is doing is simply noting that Quine’s famous thesis of the indeterminacy of meaning is not some eccentricity on Quine’s part, but follows from the naturalistic assumptions Quine shares with most contemporary academic philosophers.

The trouble is that if this is correct, then there is in particular no fact of the matter about what Rosenberg or any other naturalist means when he puts forward a naturalistic thesis. Objectively speaking there is no more reason to think that their utterances express a naturalistic position than that they express a Cartesian one or an Islamic one, or indeed that they are anything more than empty verbiage. The choice is purely pragmatic, or determined by social or economic forces or toilet training, or by Darwinian selection pressures, or by whatever it is this year’s clever young naturalistic philosophers are saying determines it.

Now this is absurd enough, but naturalists have already long inured themselves to accepting such nonsense. Writers like John Searle have been pointing out the paradox for years, to no effect. It doesn’t phase the average naturalist, any more than the hardened criminal feels even a twinge of guilt upon committing his 345th felony. The mental calluses are too thick. You see, if naturalism leads to absurdity, then it must not really be absurdity; because, kids, naturalism just can’t be wrong. Only those dogmatic religious types think otherwise.

But it’s worse than all that. For it won’t do for the naturalist to say: “OK, so we’ve got to swallow some bizarre stuff. But we’re just following the argument where it leads!” What argument? There’s no fact of the matter here either – no fact of the matter about which argument one is presenting, and in particular no fact of the matter about whether one’s arguments conform to valid patterns of inference. In the case at hand, there is simply no fact of the matter about whether Rosenberg’s own arguments (or those of any other naturalist) are sound or entirely fallacious. So why should we accept them? I suppose Rosenberg could always do what any serious philosopher would when dealing with those who stubbornly disagree with him – start a petition to pressure the APA to settle the question in his favor. But until that happens, we’ll just have to wait on pins and needles.

So, that’s one fatal problem, and there’s more to be said about it. If you simply cannot bear the thought of helping to fund the purchase of my next martini or holy card by ordering a copy of TLS, then at least read James F. Ross’s unjustly neglected article “Immaterial Aspects of Thought.”

There are other incoherencies too. For example, Rosenberg keeps telling us that this or that commonsense feature of human nature is an “illusion” – despite the fact that illusions themselves are intentional phenomena, and thus the sort of thing which, on Rosenberg’s account, naturalism entails doesn’t exist. Rosenberg also seems to think that blindsight phenomena give us a reason to be eliminativists about phenomenal consciousness. But this is incoherent too, because the only reason we judge something to be a case of blindsight in the first place is that we have phenomenally conscious experiences to compare it to. Furthermore, Rosenberg assures us that the mind is merely the product of a long process of selection which favored those who were skilled at detecting other people’s motives. But since “motives” are themselves intentional mental phenomena, they can hardly coherently be appealed to in an account of how the mind originated. (Nor will it do to suggest that Rosenberg means only that our more complex minds evolved in order to detect other people’s motives; for it is the existence of any intentionality at all which poses a uniquely difficult problem for naturalism, not merely the existence of complex minds like ours.)

Of course, these are very old and very well-known problem with eliminative materialism, and eliminative materialists typically pooh-pooh them or (more commonly) simply ignore them. Even non-eliminativist naturalists do the same. What none of them do is actually answer such objections, except with “solutions” which also presuppose intentionality and/or consciousness and thus simply raise the same difficulty at a higher level. The problem is obvious, and obviously fatal, and yet amazingly, it is rarely addressed (Rosenberg’s essay completely ignores it). Victor Reppert and William Hasker have put forward what I think is the correct explanation of this bizarre state of denial: Even naturalists who are not eliminative materialists suspect that their position may inevitably lead them in an eliminativist direction, and they want to keep the option open. Precisely because the obviously fatal objection to eliminative materialism is so obvious and so fatal, the typical naturalist pays it little or no heed, lest he be forced by it to give up naturalism itself – a position which is, as Hasker puts it, something like “a theological dogma” for those philosophers committed to it. Like children, they hope the problem will just go away if they pay it no attention.

Let’s move on to the second claim I have said is given some further confirmation by Rosenberg’s essay:

2. There are no non-question-begging arguments for naturalism: Rosenberg’s thinks we have to accept the depressing consequences he outlines because he thinks naturalism is clearly true. Why?

The only argument he gives – implies, really – is the standard, tired “heroic age of science” argument: Modern science implies naturalism, so it must be true. But why accept this conditional? It would certainly come as news to Galileo, Descartes, Boyle, Newton, Leibniz, Locke, and many of the other founders of modern science and philosophy who (given that they were theists and/or dualists of one stripe or another) rejected naturalism (not to mention the many non-naturalist scientists and philosophers who have succeeded them, down to the present day). It also comes as news to us reactionary Aristotelians and Thomists, who hold that an Aristotelian-Thomistic (A-T) metaphysics and philosophy of nature is perfectly compatible with the findings of modern science.

But Rosenberg assures us that 17th century scientists and philosophers of the stripe just mentioned “purged” or “ruled out” Aristotelian formal and final causes and the like. If what Rosenberg means by this is that they decided simply to ignore formal and final causes, then he is right. But if what he means is that they somehow refuted the claim that formal and final causes exist, or even cast the slightest doubt on their existence, then he is most definitely wrong, as I have argued at length in several places, including TLS and Aquinas. Indeed, as I argue there, the reality of formal and final causes is in fact rationally unavoidable.

But even if we A-T types are wrong, that would do nothing to show that naturalism is true, because there is still the non-naturalistic interpretation of science defended by dualists, idealists, and representatives of other modern schools of thought which accept the broadly mechanistic or non-teleological conception of nature endorsed by naturalists, but deny that nature so conceived is all that exists. True, their position is currently a minority view. But X is the majority view among contemporary academic philosophers does not entail X is true or even X is the only view worth taking seriously. Indeed, by itself it does not even entail X is plausible.

Anyway, whenever Rosenberg or some other naturalist tells you that “Science has shown such-and-such,” what he really means is “Science as interpreted in light of a naturalistic metaphysics has shown such-and-such.” And when he is telling you specifically that what science has shown is that naturalism is true, what he is doing, accordingly, is begging the question. Nothing more. Which brings us to:

3. The hegemony of naturalism over contemporary intellectual life owes entirely to philosophical muddleheadedness, ignorance of philosophical history, and anti-religious animus: We’ve already noted a fair bit of muddleheadedness. Rosenberg’s implicit assumption that realism about the mental entails the view that a thought is a kind of inner “representation” is a possible instance of ignorance of (a big chunk of) philosophical history. As I have noted in several earlier posts (e.g. here), this “representationalist” conception of thought is a modern, Cartesian, and entirely contingent assumption that classical and medieval thinkers would have rejected (rightly, in my view).

In general, contemporary naturalistic philosophers – or at least those whose naturalism is “scientistic,” as Rosenberg’s self-consciously is – tend to have little or no knowledge of the many deep differences between modern, Cartesian versions of dualism and classical (Platonic or Aristotelian-Thomistic) ones, between modern rationalist and empiricist arguments for God’s existence and classical (Neo-Platonic or A-T) ones, and so on. They assimilate the classical theories to the modern ones and thus falsely assume that refuting the latter suffices to refute the former. (Even then, their understanding of modern forms of non-naturalism is often laughable; e.g. they often claim that Cartesian dualism involves “positing” the existence of “mind-stuff” or “ectoplasm.”)

How about the animus against religion? Well, Rosenberg tells us that a belief in meanings and purposes is what puts us on a “slippery slope” to religion. About that he is, I would say, absolutely right. But of course, that gives us a reason to endorse Rosenberg’s rejection of purposes and meanings (as he seems to think it does) only if we already know that no religion is true. Naturalism, we all thought, was supposed to show us that religion is an illusion; now, it turns out, naturalism merely assumes this.

Beg the question much?

UPDATE: Rosenberg has now replied to his critics (scroll to the bottom of his combox) and I comment on his reply here.

Plato’s affinity argument

In an earlier post I suggested that the arguments of great philosophers of the past need to be understood, not only in the context of their times, but also in light of how later thinkers built on them. For an argument can contain, inchoately, real insights which only later thinkers were able to spell out adequately; and we will miss these insights if, overly fearful of anachronism, we insist pedantically on reading the argument in isolation from this later tradition. What ultimately matters in philosophy is not exactly who said exactly what, exactly when and exactly how. What matters is what is true, and whether an argument is likely to lead us to it. Anachronism, then, while a danger, is a less serious danger than loss of truth. To think otherwise is to abandon philosophy for mere scholarship. (Scholarship has its place, of course. But its place is to serve the ends of philosophy.)

What immediately prompted that post were some reflections on Plato’s Phaedo, on which I had been lecturing at the time. The Phaedo is famously concerned with the immortality of the soul, and Socrates is represented as putting forward four main lines of argument in its defense – or rather, as commentators these days often emphasize, four sub-arguments in the course of what should be understood as a single long, complex argument. Modern readers of the Phaedo often dismiss the arguments as manifestly bad. David Stove, in The Plato Cult, describes them as “so contemptible that, on their own merits, they could hardly ever have imposed upon a child of eight” (pp. 100-1). This sort of judgment is, I think, completely unwarranted. When understood both in the context of Plato’s philosophy as a whole and in light of the ongoing classical tradition of thinking about the soul which Plato inaugurated, his arguments can be seen to be very interesting indeed. That is not to say either that Plato’s arguments are adequate as they stand or that all of them can at the end of the day be defended. It is to say instead that the arguments embody serious considerations in favor of the soul’s immortality, and that at least some of these considerations were developed by later writers into more complete and compelling arguments. Modern readers often fail to see this because – as with their treatment of Aquinas’s Five Ways – they too frequently lack familiarity with the metaphysical presuppositions of the arguments, and read into them modern assumptions which classical writers did not make and often would have rejected.

The four arguments in question are usually labeled the cyclical argument, the recollection argument, the affinity argument, and the final argument. Let us begin by briefly surveying the arguments. It is evident from the dialogue that the cyclical and recollection arguments are intended to work in tandem. Putting aside the details of the examples Socrates uses in stating them (e.g. the long discussion about the Form of Equality) we might summarize the case that these first two arguments are together intended to make as follows:

1. We have knowledge (of Forms and of mathematical truths) that could not have come from sensory experience or in any other way been learned during this life.

2. So it must have been acquired during an existence prior to this one.

3. So our souls must have pre-existed their embodiment in this life.

4. But things arise out of their opposites in a cyclical pattern, such as sleeping from waking and waking from sleeping.

5. So, just as souls pre-exist their embodiment during life, so too must they continue on disembodied after death.

One way this line of reasoning might be challenged is via the suggestion that even if our souls pre-existed this life, perhaps their embodiment has altered them to such an extent that they will not survive our deaths, the “cycle” being thereby broken. Answering such an objection seems to be the point of the affinity argument, the core of which might be summarized as follows:

1. The soul knows the Forms, which are eternal, whereas the senses know material things, which pass away.

2. But each of these faculties is like the thing it knows (e.g. the senses are material, the soul is invisible).

3. Thus it is because the senses are like the things they know that they too pass away.

4. So the soul, since it is like the Forms that it knows, must not pass away.

Following Socrates’ presentation of the affinity argument in the Phaedo, his interlocutors Simmias and Cebes raise some further objections, including Simmias’s famous suggestion that the soul may be a mere harmony or attunement of the body’s components, like the harmony of a lyre. This begins a long discussion which culminates in the final argument, which might be summarized as follows:

1. The soul is the principle by which a thing is alive.

2. So it participates in the Form of Life.

3. But a thing cannot participate in contrary Forms (e.g. fire, which participates in the Form of Hot, cannot participate in the Form of Cold).

4. So the soul cannot participate in the Form of Death.

5. So the soul cannot perish.

Now I have no intention of exploring each of these arguments in any detail. Indeed, the line of reasoning enshrined in the combination of the cyclical and recollection arguments is one which I – as a Thomist who takes the soul to be the form of the body – do not think can succeed at the end of the day. One obvious objection to it is that its first premise is false if (as I would maintain) an Aristotelian analysis of concept formation is correct. Another is that step 2 doesn’t follow from step 1 all by itself: Even if our knowledge of forms and of mathematical truths cannot have come from the senses, it may be that it was stamped into our intellects by God when He created our souls (as per a rationalist theory of innate ideas) or that it results from a kind of divine illumination (as per St. Augustine). And of course, the stuff about things arising out of their opposites needs to be tightened up, to say the least. All the same, I’m sure a serious Platonist could give the argument a run for its money, and it would be a useful philosophical exercise to see how far it could be defended against objections. Much farther than most contemporary readers would suppose, I would bet.

Anyway, it is the second two arguments that I think are the most interesting. In the case of the final argument, this is not because it is sufficient to establish personal immortality. It is not. But what it does do, it seems to me, is foreshadow the Aristotelian-Thomistic insight that while particular composites of matter and form – that is, individual material substances – are generated and pass away, form itself (and thus the soul) is not susceptible of perishing. For a material substance’s perishing just amounts to its matter losing its form, and a form can’t coherently be said to lose its form (because it is a form). But then, since the soul is (on the A-T analysis) just a kind of form, the soul is not susceptible of perishing.

The reason this does not by itself establish personal immortality is that the forms of material things, considered by themselves, are in general mere abstractions. What exist concretely are individual material substances, and thus form and matter together. For this reason, matter too, considered apart from form, is a mere abstraction – speaking concretely, matter always exists with some form or other. And thus, if the soul qua form were imperishable merely in the sense just described, it would be no more imperishable than matter is. As Aquinas says in On the Principles of Nature, “prime matter [i.e. matter without form], and even form, are neither generated nor corrupted… properly speaking, only composites are generated” (2.15). A thing’s matter carries on after its destruction in the sense that the matter simply takes on a new form; its form carries on in the sense that some new substance with the very same form can always come into being. It is only the individual concrete substance that the form and matter together compose which comes into being and passes away. Since it passes away, though, the survival of its form – its soul, in the case of a living thing – merely qua something which another, future substance might take on, does not entail that the substance itself survives in any sense. When a particular rose bush dies, its form carries on in the sense that new rose bushes can always come into being, but that rose bush is gone for good.

For the imperishability of the human soul to ensure personal immortality, then – the survival not merely of the abstract form of man, but of your form or soul specifically – it would have to be what the forms of other material things in general are not: a kind of subsistent form, something whose operations are not, or at least are not entirely, dependent on matter. That is to say, it would have to be something which operates as a kind of immaterial particular thing even when it informs the matter of the body. Only then would its survival count as the survival of the particular human being whose soul it was. Or rather, it would count as the survival of the chief part of that particular human being; for the whole human being to come back into existence, the soul would have to be reunited with the matter that made up its body, which in Aquinas’s view it does at the resurrection. But the survival of the soul as a kind of immaterial particular at least makes this possible in a way it would not be if the human soul were like every other form.

I spell out Aquinas’s position in detail in chapter 4 of Aquinas. The point for now is that the reasons why the soul should be understood as something which operates independently of matter are not to be found in Plato’s final argument. But they are hinted at in Plato’s remaining argument for the soul’s immortality, namely the affinity argument.

As it happens, the affinity argument is the one some commentators seem to regard as the worst of Plato’s arguments for the soul’s immortality. One reason for this is that they often interpret it as an argument from analogy. That is to say, they think Plato is arguing along something like the following lines: If the soul is like the Forms in one respect – namely, being invisible to the senses – then it is probably like them in another respect as well, viz. in being imperishable. The trouble with the argument, then, is obvious: The analogy is simply too weak and undeveloped to support the conclusion.

It is understandable why a modern reader would read the argument this way. Plato does make use of an analogy, after all. And modern readers are used to thinking of metaphysical arguments as quasi-empirical hypotheses a la Paley’s “design argument” for God’s existence. But as every Thomist knows, not every philosophical use of analogy constitutes an “argument from analogy” in the modern sense, and metaphysical arguments (or good metaphysical arguments, anyway) are not quasi-scientific empirical ones. A failure to make these distinctions is what leads so many modern readers to misread Aquinas’s Fifth Way as a precursor of Paley. It is also what leads them to misread Plato as offering a lame argument from analogy for the immortality of the soul.

In fact, as Michael Pakaluk has pointed out, the affinity argument is not an “argument from analogy” at all, but rather “an argument about the nature of things.” Plato is not saying: “The soul is like the Forms in one way, so there is some significant probability that it is like them in this other way too.” Rather, he is saying something like: “The soul of its nature is X. But as we know from the example of the Forms, which are also X, things that are X are imperishable. So the soul is imperishable.”

What is X? As Lloyd Gerson suggests in his book Knowing Persons: A Study of Plato, what Plato seems to be emphasizing here is that the soul, like the Forms, is immaterial (p. 86). What the argument is (arguably) saying, then, is that whereas the senses pass away just as the things they know pass away, because both are material, the soul by contrast must be as imperishable as the things it knows – namely the Forms – because like the Forms, it is immaterial. In other words, it is, on this interpretation, the immaterial nature of the Forms that makes them imperishable, so that something that shares that nature – as (the argument claims) the soul does – must be equally imperishable. Notice, again, that this is not a probabilistic argument from analogy, but, in effect, an attempt at a proof. The argument is not:

1. The Forms are imperishable.

2. The soul is in some other respects analogous to the Forms.

3. So it is probably like them in being imperishable too.

That would indeed be a bad argument. Rather, the argument is (I am suggesting) to be understood along something like the following lines:

1. What is immaterial is imperishable.

2. The Forms are immaterial.

3. So the Forms are imperishable.

4. But since the soul knows the Forms, it must be as immaterial as they are.

5. So the soul must be imperishable.

Say what you will about this argument, it is not an argument from analogy, and it is not probabilistic. (Leave such weak tea arguments to the moderns. The ancient and medieval philosophers preferred the strong drink of metaphysical demonstration.)

OK, but what of the crucial premise 4? If it does not rest on an argument from analogy, what does it rest on? I would suggest that what Plato is gesturing at here is a line of argument that would later be developed more thoroughly and carefully by writers like Aristotle and Aquinas. The basic idea is that the intellect’s grasp of an abstraction like triangularity (for example) would simply not be possible unless it were as immaterial as triangularity itself is. There are three main considerations in favor of this judgment:

A. For a parcel of matter to take on a form is for it to become a thing of the kind the form is a form of; for example, for it to take on the form of triangularity is just for it to become a triangle. Now for the intellect to grasp the nature of a thing is just for it to take on the form of that thing. And in that case, if the intellect were material, it would become a thing of the kind that it grasps; for instance, it would become triangular when it grasps the form of triangularity. But this is obviously absurd. So the intellect is not material.

B. Forms and our thoughts about them are precise, exact, or determinate in a way no material thing can be even in principle; hence a thought cannot possibly be anything material.

C. Forms are universal while material representations are necessarily particular; hence to grasp a form cannot in principle be to have a material representation of any sort.

Obviously these arguments need spelling out, and I have said much more about them in several places. All of them are discussed in The Last Superstition (see especially pp. 123-126) and at greater length in Aquinas (see especially pp. 151-159), and both books set out in detail the metaphysical background apart from which the arguments cannot properly be understood. Arguments of the sort represented by B and C are discussed in more detail in the “Intentionality” chapter of my book Philosophy of Mind. Argument B in particular was the subject of an earlier post, and has in contemporary philosophy been developed most thoroughly by James Ross (see e.g. his article “Immaterial Aspects of Thought”). The point for now is that there is a family resemblance between what Plato was apparently up to in the affinity argument, and later arguments in the broad classical tradition that attempt to show, not by means of probabilistic arguments from analogy, but on the basis of an analysis of the nature of thought itself, that the soul (or its intellectual powers, in any event) cannot even in principle be material.

Apart from their misguided tendency to interpret classical metaphysical arguments as quasi-empirical hypotheses, another reason modern interpreters often badly misunderstand the affinity argument may be that, as Gerson notes, they tend to take for granted a post-Cartesian “representationalist” conception of knowledge (Knowing Persons, pp. 81-2). But the classical and medieval approach to knowledge was in general not representationalist. The great pre-modern writers did not regard the mind as a veil of “representations” which needed somehow to be correlated with external objects and events. Rather, for them knowledge involved a kind of union – not a correlation, but an identity of sorts – of the knower and what is known, insofar as when we know, one and the same essence or nature exists simultaneously in the intellect and in the world. (I have discussed this idea at greater length in an earlier post.) Naturally, then, if the object of knowledge is immaterial, that with which it is (in some sense) identical – the state of the knower – was regarded by them as immaterial too.

Here, though, as so often happens when modern readers encounter the arguments of ancient and medieval philosophers, the clearing up of one misunderstanding is likely only to lead to another. “How can the mind possibly be identical with what it knows?” the modern reader is bound to ask incredulously. “What absurdity!” Just as they often assume (with little or no argument, other than an appeal to the authority of Frege) that the concept of existence is entirely captured by the existential quantifier, so too might contemporary readers assume that the concept if identity is entirely captured by the identity relation as it is understood in modern logic. But this would be a mere prejudice. As Gyula Klima has emphasized in a series of important papers, the metaphysical doctrines of pre-modern philosophers typically presuppose semantic and logical doctrines that are very different from, but every bit as sophisticated and defensible as, those taken for granted by most contemporary philosophers. (What I have to say in the earlier post just linked to, and what I have said in recent posts about the Thomistic doctrine of analogy, may provide at least a hint of some of the differences. But this is a gigantic topic of its own.)

In general, while contemporary readers know that the difference between their view of the world and that of the ancient and medieval philosophers is radical, they generally do not know just how radical it is. Indeed, their ignorance of the differences is so great that they typically do not so much as even understand what the ancients and medievals were saying – hence (for example) they regard Aristotle as having put forward a “functionalist” “philosophy of mind,” Plato as having given an “argument from analogy,” and Aquinas as having foreshadowed Paley. In short, the moderns insist on reading the great figures of pre-modern philosophy as if they were all essentially just less well-informed versions of themselves – a double insult.

I suggested in an earlier post that Descartes’ “clear and distinct perception” argument for dualism represents a corrupted version of earlier and better Scholastic arguments. What is true in it isn’t new, and what’s new isn’t true. But if Descartes marks a decline, Plato’s affinity argument marks the beginning of an ascent. It is a mark of our own philosophical impoverishment that we can no longer recognize either the ascent or decline for what they were – much less the power of the Aristotelian-Scholastic arguments to which the ascent led and away from which the decline has taken us.

Of course, you might not agree with me about that. So at least agree with the more measured words of Gerson, with which I’ll conclude: “[The affinity] argument, like the others, is not supposed to stand on its own. And at its core there is an argument which, far from being inconsequential, is the origin of a family of immensely influential arguments for the immateriality of the person. These arguments are refined and elaborated upon by countless later Platonically inspired philosophers. They are still, in my view, worthy of interest.” (Knowing Persons, p. 79)