In these final two chapters, I want to introduce “neutral” theories about mind and body. The neutral theories do not try to extract mind from matter, by tortuous logical means, as physicalism does, or to dissolve matter into mind, improbably, as idealism does. As a result, in theory at least, the neutral theories ought to have less of a problem with the relation of mind and body. Some of the neutral theories start with qualia or phenomenal properties as a sort of given, so it will be good to start by looking again at phenomenal properties. Phenomenal properties are something of a touchstone of any theory. If the theory has a successful account of phenomenal properties, it at least has a chance of being true. If it has none, it is doomed from the start.
It seems obvious that we do experience phenomenal properties. How could it not be true that we experience the color of the ceiling, an off-white, say, or the taste and smell of a macchiato coffee, or the sound of a tree falling gently in the forest? These are all phenomenal properties. When I say that we “experience” phenomenal properties, I mean simply to generalize the verb that goes with the sensory modality in which the phenomenal properties appear. So, for example, we see colors, and we hear sounds, and so on, but I shall sometimes say that we experience colors, which admittedly sounds a bit odd, almost sensual, and that we experience sounds, and so on, meaning by “experience” nothing more than “see, or hear, or …”.
It would be more natural to call all the things we experience by their proper names (“colors,” “tastes,” “smells,” “sounds”), and to say that we see and test and smell and hear them, but we can perhaps accept “phenomenal properties” as a generic name for all of these things, and no harm done, provided that we remember that we are talking about colors, or sounds, or tastes, or smells, or sounds or whatever is experienced, and that they are all very different from one another. One of the dangers of using the generic word “experience” is that we may think that there must be something common to seeing and hearing and so on, called “experience,” perhaps in addition to seeing and hearing, and that we can catch ourselves in the act of experiencing it.
I find it difficult to think of anything that all the phenomenal properties, or whatever they are called, have in common, or what they all are. Colors are seen, certainly, and sounds are heard, smells are smelled, tastes are tasted, and so on, and, in the dangerous philosophical jargon that we have just accepted, they are all perceived or experienced. They are all the objects of experience, but of course that doesn’t narrow things down much. Revolutions, skyscrapers, and lunar landings are all experienced, but so are bursts of anxiety, insincerity, and burglars.
Phenomenal properties, like qualia, are sometimes supposed to be experiences; but sometimes they are supposed to be properties of experiences.
Suppose that they are properties of experiences. What we experience are experiences, presumably, so if phenomenal properties are properties of experience, then we do not experience them. Suppose on the other hand that the phenomenal properties are the experiences themselves. If this is so, one is bound to wonder what the experience itself is like—the bare experience—without the property to ginger it up with content, and how it might differ from itself with and without a property. These are all silly options, no doubt, but it shows what a tangle one can get into with terminology like “phenomenal property,” “qualia,” “sense data,” “sense contents,” and other made-up words in philosophy, including “experience.” Gilbert Ryle once gave a lecture in which he denied the existence of experiences. During the discussion period afterward, Donald MacNabb asked, “How would it be, Gilbert, if I were to kick you on the shin?” “Yes, Don,” replied Ryle, “that would be an experience.”
There is something grammatically off about saying either that a color is an experience (not at all the same thing as saying that a color is experienced), or that a color is a property of an experience. On the first option, we are able to say that a color might last ten minutes, since it is an experience and an experience can last ten minutes, which is absurd. On the second option, we have to say that the color of my experience is off-white, or, worse, that my experience is off-white colored, rather than that I have an experience of an off-white color. We should no more say that an off-white color is a property of an experience, because we experience an off-white color, than we should say that an elephant is a property of an experience, because we experience an elephant. “Off-white” can be a grammatical subject, when it is a noun, just as much as “elephant” can.
My own view is that colors and sounds and the rest are neither experiences nor properties of experiences, nor phenomenal properties, if these are any different from colors and sounds, or qualia. It remains perfectly true that we see colors and hear sounds. Colors and sounds are the objects of experience, the “proper” objects of experience in fact, as philosophers have called them, not properties of experience at all. Suppose I see a nice red strawberry. Then the red color is the “proper” object of perception, and the strawberry itself is the physical object that we see by or in seeing the color. The strawberry is the object, but not in this parlance the “proper” object. One of the ways we can tell that what we are seeing is a strawberry is by its color, though three-dimensional shape is perhaps even more important. (On the other hand, what would we make of something shaped like a strawberry and blue in color?)
The tendency to locate colors and sounds and the other phenomenal properties in the mind, whether as experiences or as properties of experiences, has a long and troubled history, and I will give a brief account of a relevant part of it to orient readers to my own view, and to prepare them for what is coming in the final chapter on neutral monism.
The place to begin is with John Locke’s well-known distinction, following the terminology due to his contemporary Robert Boyle, between primary and secondary qualities.1 The primary qualities must not be confused with qualia. “Primary qualities alone” really exist in bodies in such a way as to “resemble” our perceptions or “ideas” of them, whereas the ideas of secondary qualities do not resemble the “powers” in bodies that cause them; or so Locke thinks. So the “ideas” of the Lockean qualities, both primary and secondary, are phenomenal properties, but the qualities themselves are not. For Locke, the character of the whiteness that we experience, the quale, resembles nothing in the white thing itself, unlike the character of the square that we see. The only connection is that the white thing will cause the experiences or qualia of whiteness, just as the square thing will cause the experiences of squarenesses. But in the latter case there is a resemblance, in the former not.
Locke gives a truly terrible argument for this conclusion about resemblances. The cause of whiteness does not resemble whiteness, because white disappears in the darkness, whereas the cause does not! Well, does it disappear in the dark? In the dark, it’s hard to see, surely, so how would one know that it had disappeared? By a spectrophotometric check? Well, would it be a visual spectrophotometer, or one that records levels of radiation at particular wavelengths? If it is a visual spectrophotometer, one will see nothing, because the instrument doesn’t work in the dark. The spectrophotometer itself will anyway disappear in the dark. If color does disappear, visually, in the dark, then so does everything else, visually, including squares. So the ideas of squares are the ideas of secondary qualities. Locke gives lots more bad arguments for the same conclusion.
However, it is important to know that Locke’s distinction corresponds exactly to what was required by the emerging science of the time, the new science that was taking shape in the scientific revolution. The primary qualities are the mathematical ones, such as shape, number, and size. The secondary qualities, which are perhaps in a way more qualia-like, are colors, sounds, tastes, and so on. (Still, it is important to remember that when I see a square, remembering too that shape is a primary quality, then there is a square quale, or a square, as I should call it, just as there is whiteness if I see something white. For Locke, the difference between the two cases is that the idea of the primary quality resembles the quality, whereas the idea of the secondary quality does not.) The science of Locke’s time looked to things like compression and rarefaction of groups of particles to explain sound, or the size of particles to explain hue and color, regarding the qualitative or experienced sound or color as the idea of a secondary quality, or, as Newton says, as the sensation of color. In the Opticks, published in 1704, Newton aligned large particles with red, smaller ones with blue. A barrier through which the particles can pass will deflect the large particles at a less acute angle than the small ones. Wave theories of light, such as Huygens’s, also separated what we experience in the way of light from its physical essence.
During the scientific revolution the qualitative aspects of experience were being pushed into the mind in the scientific view of the way things are, leaving a mathematical world for science to investigate—very successfully, as it happened. The mind was conveniently understood as whatever was left over from the successful mathematical sciences. For example, geometrical optics with its laws of reflection and refraction and so on did not include colors. Therefore they were in the mind and not in the physical world, except as tendencies to produce sensations of colors.
During the scientific revolution … the mind was conveniently understood as whatever was left over from the successful mathematical sciences.
The conception of the phenomenal property and of the quale results from a world conceived, for the purposes of science, as separated into two very different and incompatible pieces: matter, consisting of linear dimensions or extension, and mind, consisting of consciousness, in Descartes’s version, or sensations, in Newton’s.
The word “qualia,” however, was not introduced into philosophy until 1929, when it was first used by the American philosopher C. I. Lewis, but for him qualia were to be understood as properties of things called “sense data.” These objects were notoriously difficult to define, but it is fair to say that they were experiences taken (if such a thing is possible) as entities. It is interesting that since Lewis’s time the philosophical work that sense data did in mid-twentieth-century philosophy of mind and perception has been turned over to qualia. Like sense data, they have a special relationship to consciousness, in the sense that there can no more be an unsensed sense datum than there can be an unexperienced quale.
It is also interesting that when in 1910 G. E. Moore began to use the term “sense datum,” which had been introduced in 1885 by Josiah Royce, Moore was unsure whether sense data were parts of the surfaces of material things. So his conception of sense data was not one in which they were necessarily either experiences or properties of experiences. They might have been entirely physical, and Moore found it very hard to decide on the answer to the question.
In spite of the difficulty of characterizing what one might call the content of our experience, or the things that we experience (colors, sounds, tastes, feelings, awareness of anger, uneasiness, pains, pangs of guilt, a feeling of imbalance, and so on) it is, I think, best to start from their undeniable presence, without trying to characterize them in a way that abstracts away from their ordinary and more accurate characterization as colors, sounds, and the rest. The abstraction—calling them all phenomenal properties or qualia, without being able to explain what this means—also severs them from their relationships with the other things we experience, and makes it hard to remember that they are the objects of experience; they are what we experience, not experience itself.
Let us therefore finally examine theories that do not use made-up words, and also accord equal weight to the physical world and to the contents of experience and mind and do not try to reduce one to the other. Most people do not find it hard to believe that there are mental things as well as physical things, even if they do not understand the relation between them—which is to say, even if they do not know the solution to the mind–body problem.
We should remember that dualism is really a neutral theory, in the sense that it favors neither mind nor matter but allows a place for both of them, though, as we have seen, it thereby creates the mind–body problem. What I want to look at next are theories that, like dualism, do allow a place for both mind and matter, including the body, but that do not create the problem, or, if they do, resolve or even dissolve it. The conclusion that we have reached so far is that things such as color, pains, the deliverances of the sense of balance, and all the rest of the things that philosophers today casually refer to as qualia or as consciousness, have to be included on the ground floor of any account of the mind–body problem. The reason is that they resist the reductive theories of mind, and over the last hundred years they have seen such theories off the field.
“Dissolutionism” about the mind–body problem is not really a single view, and nor perhaps would the word “dissolutionism” be widely recognized today, even among philosophers. The mind–body problem is to be dissolved, it is said, rather than to be solved by a philosophical or a scientific theory. The reference here is to the work of Wittgenstein, whose view was that all philosophical problems should be dissolved, rather than solved by large-scale philosophical theories. Wittgenstein himself did not devote a great deal of time to the mind–body problem as a formal problem, though the last part of his working life until his early death in 1951 was in large part devoted to thinking about mental and psychological concepts and their understanding. In a celebrated passage in the Philosophical Investigations he asks,
How does the philosophical problem about mental processes and states and behaviourism arise?—The first step is the one that altogether escapes notice. We talk of processes and states and leave their nature undecided. Sometime perhaps we shall know more about them—we think. But that is just what commits us to a particular way of looking at the matter. For we have a definite concept of what it means to know a process better. (The decisive movement in the conjuring trick has been made, and it was the very one we thought quite innocent.)—And now the analogy which was to make us understand our thoughts falls to pieces. So we have to deny the yet uncomprehended process in the yet unexplored medium. And now it looks as if we had denied mental processes. And naturally we don’t want to deny them.2
We might take a pain as an example. I feel a pain in my hand, say. This seems an unproblematic thing to say. When we try to conceptualize what has been said, we think of the pain as a state of the hand, or part of the hand, or some sort of process going on in the hand, perhaps having to do with damage to the hand. And here Wittgenstein is on very strong ground. We think we understand what kind of thing this state is, because we are comparing it to a physical state, say, a state of matter. This matter is liquid, that matter is solid; there is nothing hard to understand here. We think we have advanced our understanding when we say that the pain is a mental state, rather than a physical one. That state is physical, that one is mental. For Wittgenstein, however, the deeply problematic word here is “state,” not “mental.” How do we know that the pain is a state of the hand, and what does that mean? On the surface it hardly seems to say more than that I have a pain, and that it is in my hand. “Pain is a nonphysical state” seems to add little to that, and yet it forces the mind–body problem upon us. What is the relationship between the physical state, damage to the hand, and the mental state, pain? In view of the evanescent and impalpable character of the mental, one might wish to reduce it to some physical state, perhaps a behaviorist one, as Wittgenstein imagines in the passage above.
It seems, then, that Wittgenstein’s difficulty has to do with the understanding of our first proposition, that the mind is a physical thing. Everything goes wrong when we think of the mind as a thing on the model of a physical thing, he thinks. And he is right. It is no better to think of the mind as a collection of physical states, such as pains or thoughts. What Wittgenstein’s positive views are is for the students of his later writings to determine, but it is clear that “The mind is a nonphysical thing” and “The body is a physical thing” will not pass muster with him as a description of the two key elements that feature in the mind–body problem.
What is wrong with putting the two propositions alongside one another is the false parallelism that it sets up between mind and body. It is not so much that the proposition that the mind is a nonphysical thing is straightforwardly false; the difficulty is in working out what sense can be attached to it. This turns out to be no easy project. Here is the physical state, say, electrons buzzing around atoms, and other particles doing their dance, and here is the mental state, with a pain quale attached. This sort of “Heath Robinson” metaphysics immediately follows from something as innocuous looking as the first two propositions in the mind–body problem: the mind is nonphysical, and the body is physical. The difficulty, for Wittgenstein, is in reaching a commanding perspective from which to view the first proposition, and it was to this project that he devoted his later work on the philosophy of psychology.
The distorting parallel drawn between the nature of mind and of the body is also the theme of Gilbert Ryle’s 1949 book on The Concept of Mind. Ryle agrees with Wittgenstein that there is nothing wrong with the ordinary use of mental concepts and words in the sentences we utter throughout our daily lives, but that it is another matter to understand what these words and sentences mean.
Ryle writes that we make a “category mistake” when we put concepts into “logical types to which they do not belong.”3 Things get interesting when the result is a mistaken conception of the objects of these concepts. Ryle’s classic example concerns the Oxford colleges, which collectively make up the University of Oxford. He imagines a visitor to Oxford, who does not understand the fact that Oxford is a collegiate university, seeing all the colleges and then wondering where the university is to be found. The visitor might conclude, on not finding the university in any physical place in or near the city of Oxford, that it is instead to be found, an ethereal and invisible college, in a nonphysical place. The mistake such a visitor has made is to put the concept of the University into the same category as the concept of the colleges. Ryle calls this a “category mistake,” and it occurs when something of one category is put into another category to which it does not belong. (Ryle’s simile works perfectly well as it is intended, though it is not strictly accurate, since, for example, apart from the forty-four halls and colleges that comprise the University of Oxford, as such, it owns and administers various entities, such as the Botanic Gardens and museums that belong to no college, and it sets examinations and awards degrees, which no college does. So in some sense the University of Oxford is something over and above its colleges.)
Another interesting and more difficult instance of the category mistake can be found in the attempt to say, in the same “logical tone of voice,” as Ryle puts it, that I have a left-hand glove and a right-hand glove, and that I have a pair of gloves.
It is perfectly proper to say, in one logical tone of voice, that there exist minds, and to say, in another logical tone of voice, that there exist bodies. But these expressions do not indicate two different species of existence, for “existence” is not a generic word like “coloured” or “sexed.” They indicate two different senses of “exist,” somewhat as “rising” has two different senses in “the tide is rising,” “hopes are rising” and “the average age of death is rising.” A man would be making a poor joke who said that three things are rising, namely the tide, hopes and the average age of death.4
What is wrong is the coordinating conjunctions “and” in the example of the gloves? I do not have one thing and the other thing, two gloves, and a pair of gloves, but … and here Ryle’s powers of analysis weakened before the challenge. He found himself saying that just as having a right-hand glove and having a left-hand glove is having a pair of gloves, so that the “and” is out of place, so similarly having a body, and one disposed to do such-and-such, is having a mind. In this way Ryle fell into a kind of behaviorism that he himself later came to regret, and he spent the last part of his life up until 1976 trying to make up for it. He wrote a sequence of papers devoted to the topic of thinking, trying to show how on the one hand thinking is not a higher inner “state” at all, and on the other that it is not just a bodily activity. He was convinced, however, that it is also not something we do in addition to our everyday activities. He notes that even schoolchildren know what it means to be asked to think about something, and can do it if invited to. Yet in spite of its simplicity the logic of the concept evaded Ryle’s best efforts, though his papers on the topic remain the subtlest and most clear-headed ones on the subject.
The idea of the category mistake, and its application to the mind–body problem, can certainly be pulled apart from behaviorism, even though Ryle never quite managed to do it. What we need to know is that, just as Ryle claimed, “His mind is nonphysical and his body is physical” embodies a category mistake. The sentence is a zeugma, the Greek for a “yoking together.” Another amusing zeugma is “Give neither counsel nor salt till you are asked for it,” as the proverb goes. The best-known example of a zeugma in English is “She came home in a flood of tears and a sedan chair.” Council and salt are two radically different kinds of things, and it does not make complete sense to tie them together with a coordinating “and,” and talk about them “in the same logical tone of voice.” The same is true of tears and sedan chairs. They do not belong in one category (abstract things, or “things I came home in”?), and we have in the zeugma the mistake that Ryle railed against. The psychophysical claim does indeed almost sound like the joke that the zeugma is sometimes meant to be: “His mind and his body got out of bed together; both of them were ready for breakfast.”
Yet Ryle picks on the wrong reason to criticize the mistake. What is wrong with saying that I have a left-hand glove and a right-hand glove and a pair of gloves, he thinks, is that the two gloves and the pair are one and the same thing. That may seem to be true in the case of the gloves, but it most certainly does not apply in the case of the mind and the body. “My body is stuck in the door” does not even imply that “My mind is stuck in the door,” much less amount to the same thing.
The reason that “I have a mind and I have a body” is a zeugma is not that my mind and my body are one and the same thing and that the sentences involve some kind of silly repetition. “He has a good mind” and “He has a good body” have entirely different senses. The problem with “I have a left-hand glove and a right-hand glove, and I have a pair of gloves” (assuming that what is being said is not that I have some things like a red child’s glove and a man’s gray glove and a pair of lady’s gloves) is that referring to the gloves individually puts them into one category (left- or right-handed things) and referring to them collectively puts them into another category (pairs of things that belong together). Then it seems that one can count what is in each of the two categories separately in one supracategory, and end up with the idea that I have three countable things in the supracategory: the two gloves and the pair. But there is or should be no supracategory, or else our arithmetic will go off the rails.
One can construct an inconsistent tetrad using Ryle’s example.
(1*) The pair of gloves is nonphysical (because it is an abstract set).
(2*) The left-hand glove and the right-hand glove are physical.
(3*) The pair of gloves and the left-hand glove and the right-hand glove interact. If I tear the left-hand glove and I tear the right-hand glove—lesions!—then the pair of gloves is torn; and the reverse is true, as well.
(4*) Physical and nonphysical things cannot interact.
It is reasonable to think that the big mistake is the conjunction or “yoking together” of (1*) and (2*). The conjunction means that there are two things, the pair and the left-hand glove and the right-hand glove, and they belong to two kinds of existence, one physical and one nonphysical.
The difficult thing to understand is that pairs do exist, and that a pair of gloves is not at all the same thing as a left-hand glove and a right-hand glove, even if the two gloves are a pair. It is of course true that the pair could not physically exist without the two things that make it a pair, but that does not mean that the pair and the things are one and the same anything. To what common kind, we can inquire, do gloves and pairs or abstract sets belong? Why is it so wrong to “yoke together” mind and body in the way that our first two propositions do? Suppose that someone says, “His mind and his body are in the house.” This is certainly wrong. “His mind is in the house” commits a category mistake, even if he is in the house, though not the mistake that Ryle imagined. It treats one thing (the mind) as if it belonged to a category to which it does not belong (things in space). But it is just as misleading, or even more misleading, to say, “His body is in the house, but his mind is not,” all in one breath, because that seems to imply that his mind really might have been in the house, but just happens not to be at the moment. The proposition that his mind is in the house in not merely false; it is rather that there are no circumstances under which it could be true, since there is nothing that the words could mean or come to mean, and no reason that could present itself to us that would force us to decide that it is true.
Sets and other mathematical objects exist, but there are no circumstances in which it could be right to include gloves among them. Mathematics is about mathematical objects and structures, such as pairs, but not about physical things, such as gloves. In the mind–body problem, the category mistake is the mistake of trying to put nonphysical, nonspatial things alongside physical spatial things in a causal sequence, and physical spatial things alongside nonphysical, nonspatial things in a causal sequence.
There are two more theories that commit the kind of category mistake that I have been describing, in spades, and then, stubbornly refusing to give it up, build it into the structure of the world. This is a dispiriting thing to see in philosophy, and the kind of thing that gives metaphysics a bad name. It is certainly a good thing that both the double aspect theory and panpsychism refuse, with equal obstinacy, to deny that colors and sounds and tastes and the other things collectively called qualia do exist, and that they can be reduced to things other than themselves. That does not give the proponents of these theories the right to continue to commit the category mistake.
The double aspect theory has Spinoza in the seventeenth century as its main standard bearer, and there are elements of it in the work of Thomas Nagel in our own time. According to Spinoza, there is only one substance or ultimately real thing in the universe, but it can be viewed under two complementary aspects: extension or linear dimensions, and thought. The same thing is true of the human being. It can be viewed in two ways. It can be viewed under the aspect of thought, as a mind; or it can be viewed under the aspect of extension, as a body. There are not two things here, however, and accordingly they cannot interact. Mind and body no more interact than a book classified by price, say as a $25 item, interacts with the same book classified by subject, say, as a work on astronomy. There are not two books that interact, an economic book and an astronomical book, but one book, classified linguistically in two ways: by price and by subject. The double aspect theory works by denying that mind and body interact. It remains a puzzling thing, however, why the ultimate constituents of reality should have a double aspect and manifest themselves as both thought and extension, two things that Descartes regarded as incompatible.
Mind and body no more interact than a book classified by price, say as a $25 item, interacts with the same book classified by subject, say as a work on astronomy.
True, thought cannot be reduced to extension, just as redness cannot be reduced to long-wave light. We can say that pink is a light red, but we cannot say that pink is a light long-wave light. That does not mean that we should say that everything having the color red can be regarded either as red, under its phenomenal aspect, or as producing long-wave light, under its physical aspect. Or if we do say that, we should be ready with an explanation of the relationship between the two aspects. Why should red ally itself with long-wave light particularly? What is the connection? Without some explanation, the double aspect theory simply reproduces the mind–body problem in all parts of existence. The same is true of panpsychism, the view that mind, or even consciousness, is a property of everything in the universe. The two theories give no proper account of the way in which mind and body are causally related. It is no answer to the question how the king and queen are related to say that they are both inevitable and double aspects of the monarchy, or that, appearances to the contrary, it is not surprising that they are king and queen because, appearances to the contrary, every part of existence has its kingly and queenly aspect. This is unconvincing, and at least we need to know more about the relation between the two aspects.
There is a view called “panprotopsychism” that is designed to help with this final problem, but it does so not at all. It claims that throughout nature and existence is an unknown something, an x factor, and x everywhere exhibits on the one hand mind-like or nonphysical aspects and on the other physical aspects, including bodily ones. This is what one might call a bodge job, whose only virtue is that it solves the problem created by panpsychism. Panprotopsychism agrees that panpsychism leaves us with the mystery of how the physical and the nonphysical are related. It gives the answer that both of them are derived from something more fundamental, x. But it does not tell us what x is, only that it is, or might be, and that it might produce the incompatible properties of space or the physical and consciousness.