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.

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).

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)

The Thomistic tradition, Part II

Concluding my overview of the main varieties of Thomism, with some final outtakes taken straight from the Aquinas cutting room floor:

6. Analytical Thomism: This newest approach to Thomism is described by John Haldane (pictured at left), its key proponent, as “a broad philosophical approach that brings into mutual relationship the styles and preoccupations of recent English-speaking philosophy and the concepts and concerns shared by Aquinas and his followers” (from the article on “analytical Thomism” in The Oxford Companion to Philosophy, edited by Ted Honderich). By “recent English-speaking philosophy” Haldane means the analytical tradition founded by thinkers like Gottlob Frege, Bertrand Russell, G. E. Moore, and Ludwig Wittgenstein, which tends to dominate academic philosophy in the English-speaking world. Elizabeth Anscombe (1919-2001) and her husband Peter Geach are sometimes considered the first “analytical Thomists,” though (like most writers to whom this label has been applied) they did not describe themselves in these terms, and as Haldane’s somewhat vague expression “mutual relationship” indicates, there does not seem to be any set of doctrines held in common by all so-called analytical Thomists. What they do have in common seems to be that they are philosophers trained in the analytic tradition who happen to be interested in Aquinas in some way; and the character of their “analytical Thomism” is determined by whether it tends to stress the “analytical” side of analytical Thomism, or the “Thomism” side, or, alternatively, attempts to emphasize both sides equally.

We might tentatively distinguish, then, between three subcategories within the group of contemporary analytic philosophers who have been described as “analytical Thomists.” The first category comprises analytic philosophers who are interested in Aquinas and would defend some of his ideas, but who would also reject certain other key Thomistic claims (perhaps precisely because of their perceived conflict with assumptions prevalent among analytic philosophers) and thus fail to count (or even to count themselves) as “Thomists” in any strict sense. This sort of “analytical Thomism” might be said to emphasize the “analytical” element at the expense of the “Thomism.” Anthony Kenny (who rejects Aquinas’s doctrine of being) and Robert Pasnau (who rejects certain aspects of his account of human nature) would seem to exemplify this first tendency. A second category within analytical Thomism would comprise thinkers who do see themselves as Thomists in some sense, and who would argue that those aspects of Aquinas’s thought which seem to conflict with assumptions common among analytical philosophers can be interpreted or reinterpreted so that there is no conflict. This approach might be said to give both the “analytical” and the “Thomistic” elements of analytical Thomism equal emphasis, and is represented by thinkers like Geach, Brian Davies, and C. F. J. Martin (all of whom would attempt to harmonize Aquinas’s doctrine of being with Frege’s understanding of existence) and Germain Grisez and John Finnis (who would reinterpret Aquinas’s ethics so as to avoid what Moore called the “naturalistic fallacy”). The work of Norman Kretzmann and Eleonore Stump also possibly falls into this second category, though since it is often interpretative and scholarly rather than programmatic, it is harder to say.

Thomists of other schools have been very critical of both of these strains within analytical Thomism, sometimes to the extent of dismissing the very idea of analytical Thomism as being no more coherent than (in their view) “transcendental Thomism” is. But there is a third possible category of “analytical Thomists,” namely those whose training was in the analytic tradition and whose modes of argument and choice of topics reflects this background, but whose philosophical views are in substance basically just traditional Thomistic ones, without qualification or reinterpretation. Here the “Thomism” would be in the driver’s seat and the “analytical” modifier would reflect not so much the content of the views defended but rather the style in which they are defended. The work of writers like Gyula Klima and David Oderberg seems to fall into this category. Moreover, some writers who appear to fall into the second category of analytical Thomists when writing on certain topics seem closer to this third category when writing on others. (Martin, Davies, and Haldane would be examples, since while some of their work attempts to harmonize analytic themes with Thomistic ones, at other times they are more inclined to challenge certain common analytic assumptions in the name of Thomism.)

In addition to the various schools of thought within Thomism that I have been describing, other approaches could be distinguished. For example, while Aquinas is generally understood to be an Aristotelian, commentators like Cornelio Fabro (1911-1995) have emphasized the Platonic elements in his thought. John Deely advocates bringing Thomism together with semiotics, the general theory of signs and signification. I have not attempted to be comprehensive, and what I have said about the main approaches has been brief and oversimplified. But hopefully it will give the reader some (very general) guidance through the gigantic and often bewildering body of literature on Aquinas and Thomism. In the interests of full disclosure, I might mention that my own understanding of Aquinas has been influenced most by the work of writers in the Neo-Scholastic, Laval/River Forest, and Analytical schools (especially the third category of analytical Thomism that I distinguished). In particular, I follow these approaches in reading Aquinas as the pivotal figure in an ongoing “Aristotelico-Thomistic” tradition, a “perennial philosophy” which has its roots in the best of ancient Greek thought and continues to this day.

Further reading:

Treatments of the history of and various schools of thought within Thomism can be found in: Romanus Cessario, A Short History of Thomism (Catholic University of America Press, 2003); Helen James John, The Thomist Spectrum (Fordham University Press, 1966); Fergus Kerr, After Aquinas: Versions of Thomism (Blackwell, 2002); Ralph M. McInerny, Thomism in an Age of Renewal (University of Notre Dame Press, 1968); and Brian J. Shanley, The Thomist Tradition (Kluwer, 2002). Useful collections of essays can be found in: Victor Brezik, ed., One Hundred Years of Thomism: Aeterni Patris and Afterwards, A Symposium (Center for Thomistic Studies, 1981); Deal W. Hudson and Dennis Wm. Moran, eds., The Future of Thomism (American Maritain Association, 1992); and the series Thomistic Papers published by the Center for Thomistic Studies at the University of St. Thomas in Houston, Texas. Jacques Maritain, St. Thomas Aquinas (Meridian Books, 1958) contains a useful collection of papal statements on the significance of Aquinas for Roman Catholic thought. Gerald A. McCool has developed a controversial interpretation of the recent history of Thomism in a series of books; see his Nineteenth-Century Scholasticism: The Search for a Unitary Method (Fordham University Press, 1989); From Unity to Pluralism: The Internal Evolution of Thomism (Fordham University Press, 1989); and The Neo-Thomists (Marquette University Press, 1994). His interpretation is debated in John F. X. Knasas, ed., Thomistic Papers VI (Center for Thomistic Studies, 1994).

The Neo-Scholastic approach to Aquinas is summarized in Reginald Garrigou-Lagrange, Reality: A Synthesis of Thomistic Thought (B. Herder Co., 1950; reprinted by Ex Fontibus Co., 2006). A recent treatment of Garrigou-Lagrange’s thought is Richard Peddicord, The Sacred Monster of Thomism: An Introduction to the Life and Legacy of Reginald Garrigou-Lagrange, O. P. (St. Augustine’s Press, 2005). Presentations of existential Thomism can be found in Etienne Gilson, Being and Some Philosophers (Pontifical Institute of Medieval Studies, 1952) and Jacques Maritain, Existence and the Existent (Vintage Books, 1966). John F. X. Knasas, Being and Some Twentieth-Century Thomists (Fordham University Press, 2003) is a recent defense and Ralph McInerny, Praeambula Fidei: Thomism and the God of the Philosophers (Catholic University of America Press, 2006) a recent critique. Two recent introductions to Laval/River Forest Thomism are The Writings of Charles De Koninck, Volume 1, edited and translated by Ralph McInerny (University of Notre Dame Press, 2008) and Benedict M. Ashley, The Way toward Wisdom: An Interdisciplinary and Intercultural Introduction to Metaphysics (University of Notre Dame Press, 2006). For transcendental Thomism, see Joseph Donceel, ed., A Marechal Reader (Herder and Herder, 1970). For Lublin Thomism, see Rocco Buttiglione, Karol Wojtyla: The Thought of the Man Who Became Pope John Paul II (Eerdmans, 1997). For analytical Thomism, see the chapter on Aquinas in G. E. M. Anscombe and P. T. Geach, Three Philosophers (Basil Blackwell, 1961); John Haldane, ed., Mind, Metaphysics, and Value in the Thomistic and Analytical Traditions (University of Notre Dame Press, 2002); The Monist, Vol. 80, No. 4 (1997), a special issue on Analytical Thomism edited by Haldane; and Craig Paterson and Matthew S. Pugh, eds., Analytical Thomism: Traditions in Dialogue (Ashgate, 2006).

Fossils and Frankenstein monsters

One sometimes hears it said that studying the works of Thomists only distorts one’s understanding of Aquinas. “Read St. Thomas himself, and forget the commentators!” This sounds sophisticated, or is supposed to. In fact it is superficial. No great philosopher, no matter how brilliant and systematic, ever uncovers all the implications of his position, foresees every possible objection, or imagines what rival systems might come into being centuries in the future. His work is never finished, and if it is worth finishing, others will come along to do the job. Since their work is, naturally enough, never finished either, a tradition of thought develops, committed to working out the implications of the founder’s system, applying it to new circumstances and challenges, and so forth.

Thus Thomas had Cajetan, Plato had Plotinus, and Aristotle had Aquinas himself – to name just three famous representatives of Thomism, Platonism, and Aristotelianism, respectively. And thus you cannot fully understand Thomas unless you understand Thomism, you cannot fully understand Plato unless you understand Platonism, you cannot fully understand Aristotle unless you understand Aristotelianism, and so on. “But writers in the traditions in question often disagree with one another!” Yes, and that is all the more reason to study them if one wants to understand the founders of these traditions; for the tensions and unanswered questions in a tradition reflect the richness of the system of thought originated by its founder.

Great philosophers, then, are not museum pieces, or shouldn’t be. Karl Popper famously derided the incessant “spectacle cleaning” of those linguistic philosophers who became so obsessed with the words we use to talk about philosophically problematic phenomena that they lost sight of the phenomena themselves. Historians of philosophy can make a similar mistake if they are not careful, becoming so obsessed with the minutiae of historical context that they make the arguments of a Plato or an Aristotle, an Augustine or an Aquinas, a Descartes or a Kant come to seem like fossils, so deeply embedded in the contingent controversies of their times that they can no longer speak to us today.

When an argument presented as paradigmatically Thomistic, Platonic, Aristotelian, Cartesian, or whatever is dismissed by the historian as “anachronistic” – as an accretion of the later tradition which must be stripped away in order to get at the “authentic” teaching of the founder, or as a reconstruction that goes beyond the actual text – then we are in danger of losing sight of the point of studying the thinkers in question in the first place. As Aquinas himself put it, “the study of philosophy is not about knowing what individuals thought, but about the way things are” (Exposition of Aristotle’s Treatise On the Heavens I.22). An argument as actually stated by some great philosopher of the past may be incomplete or unclear, and seem open to various objections. And yet it may also embody real insights, and contain in embryonic form a more compelling line of thought that later thinkers in the tradition have merely refined and strengthened rather than made from whole cloth. To ignore the latter is not to do justice to the thought of the founder, but precisely to do him an injustice. More to the point, it is to risk failure to discover the truth about some substantive philosophical matter in the name of a pedantic, narrow conception of “scholarship.” Hence those who study (for example) Plato’s arguments for the immorality of the soul and the theory of Forms, or Aquinas’s Five Ways, while ignoring the ways later Platonists and Thomists have interpreted and defended those arguments, blind themselves to the real power of these ideas.

As every Aristotelian knows, however, vices tend to come in pairs. And in avoiding the mistake of fossilizing great thinkers of the past, we must take care not to fall into the opposite error of making them over in our own image. This is what occasionally happens when the contemporary analytic philosopher pulls a volume of some great philosopher of the past off the shelf and decides he’s going to do said philosopher the favor of reconstructing his arguments in a style that might make them acceptable to a referee for Nous or The Philosophical Review. The result is sometimes interesting. But sometimes it involves (say) attributing to Aristotle a “functionalist” philosophy of mind, or interpreting Aquinas’s Third Way as an exercise in possible worlds theorizing. That is to say, the result is occasionally a kind of Frankenstein monster – the attempted reanimation of a (presumed) corpse via the latest philosophical technology, which yields only a grotesque distortion of the original. (Readers interested in these particular examples are referred to Aquinas, which among other things attempts to clear up some common misunderstandings of the Third Way and of the Aristotelian-Thomistic approach to the mind-body problem.)

If the historian of philosophy is sometimes overly attentive to historical context, then, the analytic philosopher is sometimes insufficiently attentive to it. If his standard of philosophical respectability is what he was taught in grad school or what he hears talked about at the latest APA meeting, he is naturally going to assume that if Plato, Aristotle, Aquinas, Descartes, or whomever really has something of interest to say, it must be expressible within the conceptual boundaries with which he and his friends in the profession are familiar. But a past philosopher’s significance is not to be measured in terms of the degree to which he approximates our opinions and assumptions. On the contrary, as Christopher Martin has said, “the great benefit to be derived from reading pre-modern authors is to come to realise that after all we [moderns] might have been mistaken” (Thomas Aquinas: God and Explanations, p. 203). A failure to interpret and evaluate the arguments of a past philosopher on their own terms not only entails misunderstanding what he had to say, but also deprives us of the opportunity of uncovering possible errors or limitations in our own thinking.

The only way for a philosopher to avoid both sterile historicism and ahistorical arrogance – both fossils and Frankenstein monsters – is to strive to understand the history of his subject while always keeping in mind that this historical knowledge is not an end in itself, but a means of approaching philosophical truth. In particular, it requires understanding the ongoing traditions of thought to which many of the great thinkers of the past contributed. To understand not just Thomas, Plato, or Aristotle, but Thomism, Platonism, or Aristotelianism, as living systems, is simultaneously to situate these thinkers within their proper intellectual context and to understand their contemporary relevance.

Schrödinger, Democritus, and the paradox of materialism

Erwin Schrödinger was yet another of those early twentieth-century thinkers cognizant of the deeply problematic character of the mechanistic conception of the material world inherited from the early modern period – and yet another to see, in particular, that this conception of matter, far from opening the way to a materialistic solution of the mind-body problem, in fact created the problem and appears to make any materialistic solution to it impossible.

The reason does not (as one might suppose) have anything essentially to do with quantum mechanics, of which Schrödinger was one of the fathers. It has rather to do with a relatively simple philosophical point which was first made by the likes of Cudworth and Malebranche and repeated in recent years by writers like Nagel and Swinburne (as noted in the second of the earlier posts linked to above). Two relevant texts are Schrödinger’s essay “On the Peculiarity of the Scientific World-View” (from What is Life? and Other Scientific Essays) and chapter 6 of his Mind and Matter, entitled “The Mystery of the Sensual Qualities” (reprinted in What is Life? with Mind and Matter and Autobiographical Sketches – a more recent volume which does not include the earlier essay).

To summarize what I’ve said at greater length in earlier posts, the philosophical point in question is that the early moderns’ move of redefining matter so that it is devoid of color, odor, taste, sound, and the like as common sense understands them necessarily made these sensory qualities inexplicable in materialistic terms. Hence, if one is going to affirm the existence both of matter (as redefined by the moderns) and of the sensory qualities (or “qualia,” as they have come to be known, relocated from the external world to the internal world of the mind), then it seems one is necessarily committed to mind-body dualism of some sort (whether substance dualism or property dualism). The only way to avoid such dualism is either to reject the existence of matter (as Berkeley did), to reject the existence of the sensory qualities (as eliminativists do explicitly and most other materialists do implicitly), or to reject the mechanistic conception of matter that led to the problem in the first place (as Aristotelians do; though Aristotelianism still leads to a non-Cartesian form of dualism – what David Oderberg calls hylemorphic dualism – for reasons that have nothing to do with sensory qualities or qualia).

To be sure, Schrödinger himself does not explicitly draw an anti-materialist conclusion. He notes merely that what he calls the “objectivation” of matter – the conceptual removal from it of anything that smacks of the personal or of mind (cf. Thomas Nagel’s “objective/subjective” distinction) – makes the mind itself deeply mysterious. This is compatible with views like Colin McGinn’s “mysterianism” or Joseph Levine’s “explanatory gap” position, which affirm materialism even as they deny that we can understand, or at least (in Levine’s case) that we do in fact understand, how materialism can be true. Not that Schrödinger himself affirms this kind of view either; he simply calls attention to the problem raised by the modern conception of matter without trying to resolve it. (For my part, I consider McGinn’s and Levine’s positions non-starters. You might as well say, in response to Gödel, “Maybe the consistency of a formal system containing computable arithmetic really is internally provable after all, and our minds are just constitutionally incapable of seeing how.”)

Schrödinger’s emphasis is also less on the mind-body problem per se than on the epistemological paradox he sees implied by the modern “objectivation” of matter. As he puts it in “On the Peculiarity of the Scientific World-View”:

We are thus facing the following strange situation. While all building stones for the [modern scientific] world-picture are furnished by the senses qua organs of the mind, while the world picture itself is and remains for everyone a construct of his mind and apart from it has no demonstrable existence, the mind itself remains a stranger in this picture, it has no place in it, it can nowhere be found in it. (p. 216)

That is to say, the picture modern science (as informed by an “objectified” mechanistic conception of matter) paints of the natural world presents it as devoid of the sensory qualities and of anything personal. And yet the picture itself exists only within the minds of persons – scientists themselves – and takes as its evidential base the senses, and thus the very sensory qualities it refuses to locate in nature.

This epistemological paradox was a major theme of E. A. Burtt’s The Metaphysical Foundations of Modern Physical Science (Burtt being, as I have noted before, one of several major early twentieth-century scholars who emphasized the problematic character of the mechanistic revolution, before this theme went down the academic memory hole sometime in the 1960s). But awareness of it goes back much farther than that – indeed (and as Schrödinger reminds us) all the way back to the 5th century B.C., and in particular to Democritus, one of the fathers of atomism. In a famous fragment, Democritus imagines a conversation between the intellect, which (as Democritus naturally assumed) must endorse the atomists’ banishment of the sensory qualities from nature, and the senses, which form the evidential basis for the atomist theory:

Intellect: “Color is by convention, sweet by convention, bitter by convention; in truth there are but atoms and the void.”

Senses: “Wretched mind, from us you are taking the evidence by which you would overthrow us? Your victory is your own fall.”

It must be emphasized that Democritus is, commendably, calling attention to a difficulty facing a theory that he himself endorses; and that we have no idea how, or even if, he tried to resolve it. It is by no means obvious that any materialist in the intervening millennia has done any better. Many of them have done worse; indeed, vulgar materialists of the New Atheist stripe typically show no awareness that there is a problem here in the first place. Unfortunately, this includes Daniel Dennett, a well-known philosopher of mind. Dennett explicitly endorses an eliminativist position vis-à-vis the sensory qualities (see e.g. his essay “Quining Qualia”) – which is to his credit insofar as (I would argue) any consistent materialist must ultimately be an eliminativist anyway. What is not to his credit is his utter blindness to the deep philosophical puzzles such a position opens up, his peddling of shameless caricatures of anti-materialist views, and in general his refusal to concede that opponents of materialism are motivated by serious philosophical concerns.

Schrödinger provides us with a plausible account of the origins of this sort of blindness (in scientists, anyway – philosophers like Dennett should know better). In “The Mystery of the Sensual Qualities” he writes:

Scientific theories serve to facilitate the survey of our observations and experimental findings. Every scientist knows how difficult it is to remember a moderately extended group of facts, before at least some primitive theoretical picture about them has been shaped. It is therefore small wonder, and by no means to be blamed on the authors of original papers or of text-books, that after a reasonably coherent theory has been formed, they do not describe the bare facts they have found or wish to convey to the reader, but clothe them in the terminology of that theory or theories. This procedure, while very useful for our remembering the facts in a well-ordered pattern, tends to obliterate the distinction between the actual observations and the theory arisen from them. And since the former always are of some sensual quality, theories are easily thought to account for sensual qualities; which, of course, they never do. (p. 164)

In the case at hand, neuroscientists who begin, as every empirical scientist must, with observations – that is to say, with conscious experiences whose character is determined by various sorts of qualia or sensory qualities – go on to construct a theoretical description of the physical and neural processes associated with perception. This theoretical description then takes on, as it were, a life of its own, coming to seem as real or even more real than the concrete experiences that led to it, and the language in which the former is couched comes to be applied to the theorist’s description of the latter. Thus an explanation of “heat” in the sense of molecular motion comes to seem, especially when coupled with neuroscientific data, an explanation of “heat” in the sense of a certain kind of tactile sensory quality; an explanation of “red” in the sense of light of a certain wavelength comes to seem an explanation of “red” in the sense of a certain kind of visual sensory quality; and so forth.

But this is a muddle, a subtle committing of the fallacy of equivocation. The key theoretical concepts – molecular motion, light wavelengths, neural firing patterns, and so forth – are always understood in light of a broadly mechanistic conception of the natural world which follows the early moderns’ project of excluding final causes, sensory qualities and the like from matter and redefining it in abstract mathematical terms. To “explain” sensory qualities or qualia in such “scientific” (i.e. mechanistic and “objectified”) terms is thus really to change the subject. Earlier generations of philosophers and scientists realized this, which is why few of them were materialists – they saw that, by definition as it were, sensory qualities could not be “material” given the new conception of matter. But later generations – especially the current generation of scientists, who tend to be far more specialized and often seem less philosophically-minded or philosophically-educated than their predecessors – have forgotten this conceptual history. And this forgetfulness and philosophical shallowness together with the practical successes of modern science have hardened many of them – or at least the more vocal of the pop science writers among them – into a crude scientism which assumes that there are no philosophical problems, or at least no serious ones, which science is not capable of answering.

Thus, when philosophers come along – whether dualists or the more sophisticated and fair-minded sort of naturalist (e.g. a Searle, a Nagel, or a Chalmers) – and point out that existing neuroscientific “explanations” of consciousness and the like do not in fact explain the relevant phenomena at all, it comes to seem like these philosophers are inventing a new problem in a desperate and obscurantist attempt to salvage a belief in human dignity and specialness. In fact they are simply calling attention to a very old problem that the mechanistic theoretical model itself has created, and of which earlier generations of philosophers and scientists were well aware. In fact it is scientism which fosters obscurantism, ignoring as it does clear conceptual distinctions and forcing all intellectual life into a methodological procrustean bed. And in fact the mechanistic “objectified” conception of matter inherited from the early moderns is not a scientific discovery at all but a philosophical posit, and one which creates philosophical problems rather than solves them.

Obviously I am not claiming to establish these large claims here. (Doing so is in large part what The Last Superstition is about.) And obviously there are different moves a materialist might try to make in order to get around the problems in question (though, equally obviously, I don’t myself think any such moves can succeed). The point is that the problems are real ones, and serious ones. Any naturalist who dismisses them as motivated by irrational religious fanaticism is either ignorant or dishonest; certainly Democritus, Schrödinger, Burtt, Searle, Nagel, Chalmers et al. have no theological ax to grind. It goes without saying that our knowledge of the human brain has come a very long way since the 5th century B.C. But philosophically speaking, the history of materialism from Democritus to Dennett marks a precipitous decline.

Addendum 9/14: It occurs to me on re-reading the post that the Chalmers reference in the first sentence of the second-to-last paragraph is, coupled with the “or,” unintentionally misleading: Chalmers is a naturalist, but he is also a dualist of sorts. My apologies. The conceptual lay of the land vis-à-vis this subject is extremely complex, the range of possible positions is very large, and it is difficult briefly to summarize the issues without oversimplification – especially when (as was the case with this post) one is writing late on a Saturday night!

Is self-ownership axiomatic?

In my recent post on Murray Rothbard, I addressed the question of whether the libertarian principle of self-ownership could be said to be axiomatic. Let’s pursue the question a little bit further. In particular, let’s pursue the question of whether it is even plausible to suggest that the principle is axiomatic in the strictest sense of “axiomatic.”

Notice that I am not asking whether the principle is true; nor am I asking whether there are any good reasons, of some sort or other, to believe it. Those are separate questions. I am asking whether, if it is true and justifiable, its truth and justification are plausibly of the sort that strict axioms enjoy. Again, what I am asking is whether the principle is plausibly axiomatic in the strictest sense.

What sense is that? One traditional way of thinking about it is this: A principle is axiomatic in the strictest sense if any proposition you could give as evidence for it would be less obviously true than the principle itself is. The law of non-contradiction is a standard example. Nothing you could say in defense of the law of non-contradiction is as obviously correct as the law of non-contradiction itself is. Call this special characteristic of strictly axiomatic propositions “self-evidence.”

So, is the libertarian principle of self-ownership axiomatic or self-evident in this sense? Before you answer, keep in mind that the principle says far more than merely that (say) your right hand belongs to you. When you look at your right hand and judge, spontaneously and quite correctly, “This is mine,” you might initially be inclined to think that the principle of self-ownership must be right. Indeed, maybe it is axiomatic!

Not so fast. Your right hand is indeed yours, as is your right foot, your right eye, and every other body part you can name. All well and good – and not terribly controversial. But what exactly does that entail? Does it entail that you are entitled to do absolutely anything you want with those body parts, provided you do not infringe the liberty of others? Does it entail that you can even do things that are immoral – on the grounds that since it’s your body, you have the absolute right to abuse it so long as you harm no one else? More to the point, is it strictly axiomatic or self-evident that you can do these things?

Let’s be more specific: Is it strictly axiomatic or self-evident that, so long as you harm no one else in doing so, you have an absolute right to do the following: Commit suicide; inject yourself with heroin, even repeatedly, to the point of addiction; have a major body part surgically removed for no reason other than that you just feel like doing so; deliberately engage in self-deception (it’s your mind, after all); and, in general, do to and with yourself things you believe it is immoral to do?

Consider further: Suppose your adult child or best friend informs you that he has decided to do one of these things. To take a clear and fairly simple example, suppose he has become a devout follower of Schopenhauer and has decided, on well-thought out philosophical grounds (rather than some fleeting whim, say), to commit suicide. And suppose you try to talk him out of it, but to no avail. Is it strictly axiomatic or self-evident that you must not use force to prevent him from killing himself – such as by stealing his glass of hemlock, locking him in a padded room, or whatever? Because that is what the libertarian principle of self-ownership entails.

Again, to avoid irrelevant objections, keep in mind that the question is not whether the libertarian principle of self-ownership, radical implications and all, is true or in some way defensible. The question is whether it is strictly axiomatic or self-evident, whether it is strictly axiomatic or self-evident that one has a right to do the things mentioned above, and an obligation to refrain from keeping others, even children and friends, from doing any of them.

When we keep in mind what the principle entails, I think it is quite obvious that the principle is not strictly axiomatic or self-evident. Indeed, this is, I submit, so obvious that it is remarkable that anyone would suggest that it is – as Rothbard may have (though, as I noted in my earlier post, it is not at all clear that Rothbard really meant to use the term “axiom” in anything other than a loose and popular sense). Unlike the law of non-contradiction, it is quite easy to doubt whether the libertarian principle of self-ownership is true; indeed (and again unlike the law of non-contradiction) probably most people on considering it would judge that it is not true. Of course, that doesn’t show that it isn’t true, but it is very strong grounds for doubting that it is self-evident or strictly axiomatic. More to the point, any argument one could appeal to in order to convince the doubters that the principle is true would obviously have to appeal to premises that are more evident than the principle itself is – in which case, it simply cannot be said to be strictly axiomatic.

Perhaps the rhetoric of property led Rothbard astray here. In some contexts, saying “It’s my property” does indeed crisply settle the question of whether one may carry out a certain course of action. But not in all contexts. In everyday life, we are all well aware that the fact that you own your back yard (say) does not entail that you have no obligation in justice to allow the fire brigade access to it in order to get to the burning building behind it, or to avoid using it to engage in dangerous scientific experiments. Conversely, we are well aware that the fact that you have these various obligations does not entail that you don’t “really” own your back yard after all. In everyday contexts, that is to say, we are well aware that to say “X is my property” simply does not entail “I can do absolutely anything I want with X provided doing so violates no one else’s property rights.”

It is only when, after the fashion of “rationalistic” approaches to moral and political thinking of the sort Burke and Hayek criticized, we abstract away from the complex details of human life that property rights can seem have such extreme implications. (It happens, as Wittgenstein might put it, when we “sublime the logic of our language [concerning property].”) Property rights are not all-or-nothing. For almost all theories of property historically – and certainly for classical natural law theory, which is in my view the correct approach to moral questions generally – private property rights, even when very strong, nevertheless come with various qualifications. (For those who are interested, I develop and defend such an approach in my essay “Classical Natural Law Theory, Property Rights, and Taxation,” which is forthcoming in Social Philosophy and Policy. As I argue there, the correct approach to property rights rules out both the level of government and taxation that socialists and egalitarian liberals favor, but also the extreme laissez faire position of libertarianism. It is, in short, conservative.)

To suggest that you either go along with Rothbard or you are logically committed to going the whole hog for socialism is just too silly for words. Rothbardians seem to think their man (or maybe some precursor like Lysander Spooner) was the first thinker in history ever to think about property in a consistent way. In fact all he did was simply invent a grotesque caricature of the idea of private property.

(I recall once asking a radical libertarian what he thought he would be obliged to do if his own adult son informed him that he intended to commit suicide and he could not talk him out of it. Troubled, he thought for a moment and then replied that he hoped he would have the courage to do the right thing and allow his son to kill himself. “This,” I thought, “is a young man whose mind has been rotted out by theory.” But, being young and childless, it was merely theory, and we can have good hope that he will reconsider: Growing older and having children are pretty good cures for extreme libertarianism, though unfortunately not infallible ones.)

Anyway, if this judgment is mistaken, appealing to a purported “self-ownership axiom” is not going to show that it is.