Monday, August 2, 2010
What is the mind-body problem? In an article summarizing his work, which he wrote for Samuel Guttenplan’s A Companion to the Philosophy of Mind, Jerry Fodor answers as follows:
[S]ome of the most pervasive properties of minds seem so mysterious as to raise the Kantian-sounding question how a materialistic psychology is even possible. Lots of mental states are conscious, lots of mental states are intentional, and lots of mental processes are rational, and the question does rather suggest itself how anything that is material could be any of these.
For Fodor, then, there are really three mind-body problems: the problem of consciousness, the problem of intentionality, and the problem of rationality. Why are the phenomena in question problematic?
Let’s look at each briefly. (The following characterizations are mine, not Fodor’s.) When light strikes your retinas, a complex series of neural processes is initiated which may result in one of a range of possible behaviors – taking steps to avoid an obstacle, sorting red apples from green ones, or saying “It’s sunny outside.” When light strikes an “electric eye” or photodetector of some sort, electrical processes are initiated which also may result in one among a range of possible behaviors – the setting off on an alarm, for example, or, if the device is associated with a robot, perhaps behavior similar to the sort you might exhibit, such as avoiding an obstacle, sorting objects, or declaring (through a speech synthesizer) that it is sunny. Now, in the case of the electric eye and its associated robot, what we can observe going on in the system is presumably all there is. The system has no “inner life” or conscious visual experience associated with the electrical activity and behavior. But we do have conscious awareness; we do have an “inner life.” There is “something it is like” for us to see things, whereas there is nothing it is like for the robot to “see” something. Or as contemporary philosophers like to say, we have qualia while the robot appears not to. So, what accounts for this difference? It does not seem plausible to hold that it can be accounted for merely in terms of the greater complexity of the human brain, because the difference between conscious systems and unconscious ones seems clearly to be a difference in quality and not merely of quantity. This is the problem of consciousness.
Then there is the problem of intentionality, which concerns, not just intentions, but meaning in general. (The technical term “intentionality” derives from the Latin intendere, which means “to point at” or “to aim at,” as a word or thought points to or aims at the thing that it means.) Suppose we say that within the robot of our example there is a symbolic representation that means that it is sunny outside. Though the representation has this meaning, it has it only because the designers of the robot programmed the system so that it would be able to detect weather conditions and the like. The electrical processes and physical parts of the system would have had no meaning at all otherwise. By contrast, the thoughts of the designers themselves have meaning without anyone having to impart it to them. As John Searle has put it, the robot’s symbolic representations – like words, sentences, and symbols in general – have only derived intentionality, while human thought has original or intrinsic intentionality. What can account for the difference, especially if we assume that human beings are no less material than robots? That, in a nutshell, is the problem of intentionality.
Consider also that we are able not only to have individual meaningful thought episodes, but also to infer to further thoughts, to go from one thought to another in a rational way. This is not merely a matter of one thought causing another; a lunatic might be caused to conclude that mobsters are trying to kill him every time he judges that it is sunny outside, but such a thought process would not be rational. Rather, we are able to go from one thought to another in accordance with the laws of logic. Now, it might seem that the robot of our example, and computers generally, can do the same thing insofar as we can program them to carry out mathematical operations and the like. But of course, we have had to program them to do this. We have had to assign a certain interpretation to the otherwise meaningless symbolic representations we have decided to count as the “premises” and “conclusion” of a given inference the machine is to carry out, and we have had to design its internal processes in such a way that there is an isomorphism between them and the patterns of reasoning studied by logicians. But no one has to assign meaning to our mental processes in order for them to count as logical. So, what accounts for the difference? How are we able to go from one thought to another in accordance, not just with physical causal laws, but in accordance with the laws of logic? That is the problem of rationality.
Most contemporary philosophers of mind would, I think, agree with Fodor that this trinity of issues constitutes the mind-body problem, and I think they would also more or less agree with my statement of the problems. They do not necessarily agree about how difficult the problems are. Of the three, the problem of rationality seems to get the least attention from contemporary philosophers. Fodor himself thinks that this problem is the one contemporary philosophers have most plausibly been able to solve in a way that vindicates materialism, and that they have done so (contrary to what my statement of the problem suggests) precisely by thinking of rational thought processes as computational processes over formal symbols encoded in the brain. Most other contemporary philosophers of mind seem to agree with Fodor about this much, though there are prominent dissenters, such as Searle, Dreyfus, and defenders of the anti-materialist “argument from reason.” The greatest of the ancient and medieval philosophers would have sided with the dissenters; for Plato, Aristotle, Aquinas, et al., rationality was the aspect of human nature that could not possibly involve a material organ. (We will come back to this point.)
Contemporary philosophers, by contrast, are obsessed with the problem of consciousness, and in particular with “qualia” – something you do not see the ancients and medievals worrying about at all, certainly not as something that pointed to any immaterial aspect of human nature. Fodor, like many other contemporary philosophers of mind, regards this as “the hard problem” for materialism. The problem of intentionality also gets a lot of attention from contemporary philosophers. My sense is that in general they tend to find it more challenging than the problem of rationality but not as challenging as the problem of consciousness. My own view is that, at least as contemporary philosophers tend to understand the problem, it is in fact as great or even greater a difficulty for materialism than the problem of consciousness is. The ancients and medievals would, I think, have agreed, though they would have regarded the problem as pointing to an immaterial aspect of human nature only to the extent that it overlaps with the problem of rationality.
The reason for all this is that the problems of consciousness and intentionality, as they are understood by modern philosophers anyway, are not (as they are often assumed to be) “perennial” problems of philosophy, but rather an artifact of certain historically contingent metaphysical assumptions early modern philosophers like Descartes, Hobbes, Locke, and Co. put at the center of Western thought. In particular, they are an artifact of the “mechanistic” revolution I have discussed and criticized so frequently on this blog and in my books The Last Superstition and Aquinas.
I have explained how this is so at length, both in those books and in previous posts, but here is a brief summary. On the older, Aristotelian-Scholastic understanding of the natural world that the early modern thinkers overthrew, qualities like color, sound, odor, taste, heat and cold were taken to exist in the material world more or less in just the way common sense supposes that they do. The moderns, reviving the view of the ancient atomists, denied this: For them, the natural world is made up of intrinsically colorless, odorless, soundless, tasteless particles in motion, and the qualities in question exist only in the mind of the observer. For purposes of physics, we can in their view redefine heat and cold in terms of molecular motion, or red and green in terms of the different surface reflectance properties of physical objects, but heat, cold, red and green as common sense understands them exist only in consciousness. But since the brain is on this view made up of inherently colorless, odorless, tasteless particles no less than any other physical object, this seems inevitably to entail that consciousness is not a feature of the brain – which is, of course, exactly what Descartes, Malebranche, Locke, and other early modern thinkers concluded insofar as they embraced dualism. Therein lies the origin of what contemporary writers call the “qualia problem” or the problem of consciousness.
The older, Aristotelian-Scholastic view also held that a kind of meaning, teleology, or goal-directedness is built into the structure of the material world from top to bottom. This includes not just the usual examples – the functions of bodily organs – but basic causal relations as well. For the Scholastics, if some cause A predictably generates some specific effect or range of effects B, this can only be because A inherently “points to” or “aims at” B. Generating B, specifically – rather than C, or D, or no effect at all – is what Aristotelians would call the “final cause” of A. Causing B is what A will naturally tend to do unless impeded. Now the early moderns eliminated final causality from their picture of the natural world; this was and has remained the core of a “mechanistic” conception of nature. For them there is no teleology built into nature, no purposiveness or goal-directedness. There are brute, meaningless cause and effect patterns, but no reason inherent in nature why a cause should have just the effects it does have. One result of this was to open the way to the puzzles about causation raised by David Hume. More relevant to our interests here, though, is that it made intentionality particularly problematic. If nothing in the material world inherently “points to” or “aims at” anything else – if matter is comprised of nothing more than inherently purposeless, meaningless particles in motion – then, since the brain is made up of these particles no less than any other material object is, it seems to follow that the intentionality of our thoughts, that by virtue of which they inherently “point to,” “aim at,” or mean something beyond themselves, cannot be any sort of material property of the brain. Thus is generated the problem of intentionality.
So, Fodor’s trinity of “mind-body problems” very much reflects a modern set of assumptions about the nature of the physical world. It also reflects a presumption of materialism insofar as Fodor, like so many other contemporary philosophers, writes as if the question to ask were “How do we explain these phenomena in material terms?” Of course, a modern dualist would say that these phenomena cannot be explained in material terms, so that the right question to ask is “Given that these phenomena are not material, how are they related to material phenomena? For example, do they interact causally with them, and if so, how?” You might say that what the mind-body problem is is in part determined by how one thinks it should be solved. (“But how does positing immaterial mind-stuff explain things any better?” A common materialist retort, but not a good one, for reasons I have explained here and here.)
Notice also that Fodor says nothing about the “body” side of the mind-body problem – as if matter were unproblematic and only mind posed any philosophical difficulties. As I have noted recently, a number of prominent contemporary philosophers have emphasized that this is by no means the case. And from an Aristotelian-Scholastic point of view, the moderns’ standard assumptions about matter are perhaps even more problematic than their assumptions about mind. “Qualia” can seem necessarily immaterial only if we assume that matter is as the ancient atomists and their modern successors assume it to be; the “qualia problem,” which many modern materialists regard as such a challenge to their position (as Democritus himself did) is a problem that their own favored conception of matter created. The same is true of the problem of intentionality, at least if that is taken essentially to involve the problem of how something material can “point to” or be “directed at” something else. From an Aristotelian-Scholastic point of view, since matter is not as the atomists take it to be, and immanent final causality or teleology pervades the material world from top to bottom anyway, there is no special difficulty in regarding qualia and (at least many instances of) intentionality as in some significant sense “natural” or even “material” phenomena.
Things are very different, though, where intentional phenomena having a conceptual structure are concerned, as well as where reasoning is concerned. Here is where the Aristotelian-Scholastic tradition locates an immaterial element to human nature. The reason, in a nutshell, is that the objects of our thoughts are universal rather than particular, and determinate or exact rather than indeterminate or ambiguous; that the thoughts themselves inherit this universality and determinacy; and that nothing material can possibly be universal and determinate in this way. This is, of course, a very large topic deserving a discussion of its own. I have explored it in more detail in earlier posts (e.g. here and here) as well as in chapter 4 of Aquinas and chapter 7 of Philosophy of Mind. (The most thorough recent defense of the line of thought in question is probably the one offered in the late James Ross’s article “Immaterial Aspects of Thought.”)
The “dualism” that results is very different from the Cartesian variety, though. For the mind (or more precisely, the intellect) is not a substance on the Aristotelian-Scholastic view, but rather a power of the soul, and the soul in turn is not a substance either (or at least not a complete substance) but rather the substantial form of the living human body. Neither is the body a substance. It is rather only soul and body together which make a complete substance, where soul and body are just one instance among innumerable others of the hylemorphic form/matter relationship that exists in every material substance. Accordingly, there is no “interaction problem” of the sort that faces the Cartesian. Such a problem arises when we think of the mind as an “immaterial substance” (or as a collection of “immaterial properties”) which must somehow interact with a (mechanistically-defined) material substance via what Aristotelians would call efficient causation. But from an Aristotelian-Scholastic point of view, that is simply a category mistake, or rather a collection of category mistakes. Intellect is rather one of a myriad of powers the soul imparts to the human animal of which it is the substantial form. Thus it is formal causation which relates soul (and therefore mind) to body, not efficient causation. (I have discussed this issue in more detail here, here, and here.)
All of this is bound to sound very odd to the average contemporary philosopher. It will not sound odd, though, to those familiar with the rich conceptual apparatus of the Aristotelian-Scholastic tradition, a system of thought of which most contemporary philosophers of mind are ignorant, or at best know only through the caricatures peddled by early modern philosophers. Working one’s way out of the metaphysical assumptions moderns typically bring to bear on these issues is very difficult and takes time; the temptation is always to try to translate the thought of a Plato, an Aristotle, or an Aquinas into categories contemporary philosophers are familiar with, when what we ought to be doing is recognizing that it is precisely those categories the ancients and medievals would challenge. Thus are Plato the “proto-Cartesian,” Aristotle the “functionalist,” and other ahistorical Frankenstein monsters created. (I had not sufficiently freed myself of such modern assumptions when I wrote Philosophy of Mind, in which there is still too much Cartesianism. Chapter 4 of Aquinas provides a corrective, and a more detailed treatment of how thoroughly wrong contemporary philosophers of mind get the conceptual lay of the land, from an Aristotelian-Thomistic point of view.)
So, from an Aristotelian-Scholastic point of view, the materialist’s “problem” of explaining the three purported kinds of mental phenomena in material terms (where “matter” is understood mechanistically) and the Cartesian’s “problem” of explaining mind-body interaction are pseudo-problems. In short, while for Fodor and other contemporary philosophers of mind there are three mind-body problems, for the Aristotelian-Scholastic philosopher, there is no mind-body problem at all.