Preface

The mind–body problem is a paradox. A paradox is a group of propositions for each of which we have apparently sound arguments, yet the propositions taken together are inconsistent. We cannot affirm all the propositions in the group, yet we have good reason to believe that they are all true.

My approach is a narrower one than is usually taken to the mind–body problem, but I believe that this approach can help us to think clearly about what is going on with the particular solutions that have been given to the problem in the past. It will help us not to get lost in the metaphysics of things other than the mind and the body. The mind–body problem, in its full generality, which I introduce in chapter 1, is about the mind and the body, not about the self, or consciousness, or the soul, or anything other than the mind and the body. In chapter 5, however, I do consider some important scientific theories of consciousness as examples of scientific treatments of this part of the mind and the mind–body problem. Consciousness, the study of which has recently become important in the cognitive sciences, can reasonably be regarded as a part of the mind, though it is not the whole of it, nor is it as Descartes believed the essence of mind.

Among other questions, the mind–body problem can be taken to raise the issue of the physicality of the mind. It is certainly hard to see how it can be true that the mind, and with it consciousness, is just physical matter. We cannot watch or even imagine the neurons firing and emitting little bursts of mentality or consciousness, like diaphanous fairies flitting around the brain. The brain is obstinately physical, indeed material, weighing in at a hefty three pounds or so, but it does not make sense even to ask how much the mind weighs. One can say that the human brain is approximately 2 percent of the weight of the human being. And one can say that it contains one hundred million neurons, not to mention glial cells. But these things are not true of the human mind. We can say that the brain measures roughly five by six by four inches. Nothing remotely like that can be said of the mind. Of course, there are more sophisticated versions of materialism (the thesis that everything that exists is something material) or physicalism (the thesis that everything that exists is something physical), which I discuss in chapter 3, but the same difficulty remains buried in all of them.

Following David Chalmers, philosophers and others have wanted to distinguish the hard problem from the easy problem of consciousness, or rather the easy problems—they are many, according to Chalmers—and quite a lot has been written about this recently.¹ By the easy problems, Chalmers means the problems of describing the physical processes by which we come to have, for example, the consciousness of whiteness, assuming that we can make sense of this phrase. Clearly there are many problems of this sort. We have to understand the mechanisms of the eyes, of the ears, of touch, of the nose, and so on. The hard problem is to understand how our experience of whiteness, and with it our consciousness of whiteness, could arise from the purely physical systems operating in the visual cortex. The idea is that we can understand experience by the physical processes that go on when we perceive, but that there are properties of the experiences that cannot be understood in this way. These are the qualia, and for Chalmers they are not physical.

Fair enough, but this new twentieth-century “hard problem” is simply a souped-up version of an old problem which, as we shall see in chapter 1, appeared with Descartes and his critics in 1641. The hard problem is hard. Why? Because it is the mind–body problem, and that is a hard problem. Chalmers’s hard problem of consciousness is just the mind–body problem with a new name, complete with a very sharp distinction between the more easily understood physical processes, and consciousness or qualia, or mind. For Descartes, the principal attribute of the mind is consciousness, and so, as his critics pointed out, there is a problem about the relation of the mind to the body. This is all down to the difficulty of asserting that the mind is physical: the mind does not seem to fit into the world of physics and physiology at all. Or so claims dualism. I consider different forms of dualism in chapter 2.

In the mid-seventeenth century, the mind–body problem became a central problem—“the world-knot,” as it is often said that Schopenhauer called it—he didn’t.² What Schopenhauer would perhaps have meant had he used that phrase for the mind–body problem is that the problem signifies that our day-to-day concepts of the mental and the physical and the mind and the body are somehow tangled up in such a way that our entire conception of the world, including the physical world, is called into question by the mind–body problem. The metaphysical problem itself has only gained in significance since philosophers first became aware of it, and at the end of the twentieth century and the beginning of the twenty-first, for better or for worse, it is still alive and well.

My own view, presented in chapters 6 and 7, is friendly toward antimaterialist arguments. It is also friendly to dualism, the view that there are two distinct kinds of things in the world, not just one.

I have been thinking about the mind–body problem since I first encountered it as a student. At that time, the atmosphere in American and English universities was strongly physicalist or materialist in orientation. It is hard to recapture a sense of how strong that atmosphere was, and the way in which students who held other views felt intimidated and sidelined. I imagine that it would be very difficult now to give a historically true account of how these students moved into disciplines outside philosophy, disciplines that for them had more of a feeling for what kind of thing the mind and even the human being might be, and of what the possibilities of philosophy were. Fortunately, philosophy today is becoming more welcoming to the outsider, as it should be, not just because of a corrective politics, but because philosophy itself has realized that it fundamentally mistakes its mission if it is unwelcoming to the intellectual stranger, the outsider.

I was one of those sidelined students. For me at that time, the powerful contemporary materialism was a problem. I started in freshman year with seventeenth-century philosophy, especially Leibniz, under Professor Edwin Curley, and I felt immediately at home there. I was convinced, however, and I still am, that a really determined and sustained analysis of a philosophical view, coupled with a sense of responsibility to the language in which it is expressed, will end up arriving, at the very least, at the problems faced by that view, and at the most, at a definite knowledge about whether the view is true or false. I have read and heard nothing since I was a student that has made me doubt this conviction. Materialism might have been true. Since the 1960s it has suffered something of a decline, and several significant new antimaterialist arguments have appeared in the philosophy of mind. Chapter 4 is about these arguments. It is interesting and surprising that the new developments have taken place just as philosophy and science are becoming friendlier toward one another. It is even more interesting that these arguments have hardly disturbed the default materialist and naturalist convictions of the bulk of scientists and philosophers today. (“Naturalism” is the view that nature is all there is, so that all occurrences are natural occurrences.) Where do these materialist and naturalist convictions come from, if not from reason? Reason can of course take many forms, and one of them is the merely pedestrian or labored intellect.

Whatever view we take of the current situation, the time seems favorable to a study of the whole problem. This means more than fussing with debates about the details of the theories that have been offered for the solution of the problem. The problem is not about debates, and philosophy generally is not debate. What we need is an understanding of the structure of the problem, and of its origins in the concepts of the mind, the body, the physical, and the mental.

Why another book on the mind–body problem? Why now? The answer is that this is not another book on the mind–body problem. There has been no full-length and comprehensive book devoted to the problem for a very long time indeed. I believe that this may be partly to do with the fact that a materialist orientation is still the most natural one for many philosophers. From that point of view, the mind–body problem really is impossibly hard. For me, that is yet another reason not to be a materialist, and instead to look more carefully at forgotten or overlooked views in the history of the subject, as I do in the last two chapters of the present book, arguing for my own view (neutral monism) in chapter 7. I am particularly interested in the fact that neutral monists in the past have not given enough attention, if any, to mind–body interaction, nor have they actually stated a solution to the mind–body problem, contenting themselves instead with enthusiasm about the oneness of things. I have offered some suggestions about how to remedy this, and an analysis of how the neutral monist ought to understand mind–body interaction.

Notes

1. David Chalmers, “Facing Up to the Problem of Consciousness,” Journal of Consciousness Studies 2, no. 3 (1995): 200–219, and The Conscious Mind (Oxford: Oxford University Press, 1996).

2. Schopenhauer did use the word “der Weltknoten” (“the world-knot”), but he used it to describe the identity of the self in the unity of cognition and willing. The world-knot is the unity of the self not with the body but with the world, and the world-knot is not the mind–body problem at all. “The identity of the subject of willing with that of knowing by virtue whereof (and indeed necessarily) the word ‘I’ includes and indicates both, is the knot of the world, and hence inexplicable” (Arthur Schopenhauer, On the Fourfold Root of the Principle of Sufficient Reason [La Salle: Open Court, 1974], p. 210). See also Günther Zöller, “Schopenhauer on the Self,” in The Cambridge Companion to Schopenhauer, ed. Christopher Janaway (Cambridge: Cambridge University Press, 1999), p. 26. For Schopenhauer, the world-knot cannot be explicated (“ist … unerklärlich”), because we can only grasp the connection between objects, and the subject is not an object.