FOR AYLA
CONTENTS
Acknowledgments
Read Me
1 MIND AND BODY
An introduction to the problem—the apparent incommensurability of mind and brain—solutions and nonsolutions—a hopeless task?—Leibniz’s mill—levels of description—the promise of functionalism.
2 “PUZZLING WORK”: AN ASIDE ABOUT LANGUAGE
The difficulty of saying “just what one means”—how words convey too much or too little—speaking about consciousness.
3 WHAT HAPPENED IN HISTORY: THE INSIDE STORY
A world without phenomena—lifestuff and the importance of bodily boundaries—“me” and “not-me”—the primacy of affect—the evolution of sensitivity—representations and action plans—“what is happening to me” versus “what is happening out there”—sensory signs and perceptual signifieds—the dual track of mental evolution.
4 THE DOUBLE PROVINCE OF THE SENSES
Thomas Reid on the crucial distinction between “sensation” and “perception”—Starbuck on “intimate” and “defining” senses—problems with words—the question of how the two modes of representation are related—serial or parallel channels in the brain?
5 “WHAT DO WE SEE?”
Vision as a test case of the distinction—the embarrassment of philosophers who fail to appreciate it—how vision evolved from a skin-sense—skin becomes eye—eye remains skin—the persistence of visual intimacy.
6 COLOR IS THE KEYBOARD
Intimate responses to the “touch” of colored light in human beings—the aesthetics of color—exaggerated reactions in illness—Manfred Clynes on “sentic responses.’
7 IN THE REALM OF THE SENSES
The culture of sensation—Platonic prejudices against sensory intimacy—Romantic reactions—Impressionist painting—Kant and Cézanne on the subjectivity of beauty—sensation in “pure contemplation”—Aldous Huxley on the intensification of sensation from consciousness-expanding drugs.
8 SHUTTLE VISION
The possibility of attending selectively to one or other channel—monkeys give evidence of switching between modes—perceptual interest versus sensory pleasure—Roger Fry on a parallel distinction in people’s response to art.
9 “IT MUST LOOK QUEER!”
Why so much of mental philosophy must be guided by sensory psychology—nothing is in the mind that was not first in the senses—what is at issue for a theory of consciousness—Locke and Wittgenstein on the “inverted spectrum”—Diderot on the need for real experimental data.
10 NEW ARRANGEMENTS
Experiments to prove that sensation and perception can go their own ways—upside-down vision: perceptual adaptation without sensory change—“skin-vision”: visual perception with persistent tactile sensation.
11 MIND-BLINDNESS AND BLIND-MINDNESS
Clinical evidence for parallel sensory and perceptual channels in the brain—sensation without perception?—the visual agnosias—perception without sensation?—subliminal perception—“blindsight” after damage to the visual cortex.
12 MORE ABOUT BLINDSIGHT
What is blindsight like?—the case of Helen, a monkey who “just knew” what is out there—human parallels—blindsight as visual perception that has nothing to do with “me”—the role of sensation in “sanctioning” perception.
13 A FIRE IN THE HAND; A DAGGER OF THE MIND
The difference between “just knowing” and “feeling”—imagination and memory—the sensory thinness of images—a hypothetical case of hearing oneself hear—evolutionary considerations—the bareness of imagination marks off imagery from reality—living in the subjective present of sensation—the in-between status of images.
14 HE THOUGHT HE SAW AN ELEPHANT
Toward a theory of imagery—sensation as copying, perception as storytelling—the need to catch perceptual errors—“echoing back to the source”—where does the comparison take place?—evidence that it involves the sensory channel—illusions and “phenomenal regression to the real object”—a specific hypothesis—sensory-perceptual rivalry—dreams as a limiting case—evidence from neurophysiology.
15 HERE IT LIES
“To be conscious is essentially to have sensations”—I feel, therefore I am—eight assertions that follow.
16 HERE WHAT LIES? A CHAPTER ABOUT DEFINITION
What “consciousness” means and why the word is needed—etymological considerations—transitive and intransitive consciousness—the “having of sensations” as a natural concept—a child’s-eye view—how the word “consciousness” is learned—how it is actually used—consciousness and affect—why theories that fail to address sensation sidestep the real problem.
17 FIVE CHARACTERISTICS IN SEARCH OF A THEORY
What is it “to have sensations”?—five characteristic properties that distinguish sensations from perceptions—belonging to the subject—being tied to a particular site in the body—having a modality-specific quality—being present-tense, existing entities—being self-characterizing in all these respects—how can these features of sensations be related to a plausible mechanism in the brain?
18 THE PROBLEM OF OWNERSHIP (A TACK TO STARBOARD)
What does it mean to say my sensations are “my own”?—the problem of ownership in general—the primacy of owning one’s own body—how bodily ownership originates with the experience of control over one’s limbs—“I” as the source of voluntary agency—corroborative evidence from Siamese twins and cases of paralysis—ownership in general as de facto control—“I” as the author of my own sensations?—the possibility that sensations are a form of bodily activity “I” undertake.
19 THE QUESTION OF INDEXICALS (A TACK TO PORT)
Further analogies between sensations and bodily activities—the nature of “indexicals” and a strong argument that follows—the only way of indicating the “here” and “now” of an event is to create a physical disturbance at a “relevant” location: hence the activity of sensing must reach out to do something at the very place where the sensation is felt.
20 PLUS ÇA CHANGE
The evolutionary pedigree of sensory activity—how sensory representations began as affective responses at the body surface—the sensory epithelium was also the responsive epithelium—the “sensory loop” lengthened while the response continued to reach back to the body surface—even human sensory responses are descended from what were originally amoeboid “wriggles of acceptance or rejection.”
21 A LITTLE MIND MUSIC
The problem of what constitutes sensory quality—how could such “wriggles” (or “sentiments”) underlie the full range of human sensations?—sentiments at the body surface have an “adverbial style”—modal quality is determined by the structure of the epithelium, submodal quality by the function of the affective response—a musical analogy.
22 SPECIFIC NERVE ENERGIES?
More about sensory quality—the traditional theory of “specific nerve energies” and why it doesn’t work—putting the emphasis on output rather than input—modes of bodily acting as an analogy for modes of sensing—the possibility of an objective phenomenology.
23 SMOKE WITHOUT FIRE
“Only mental things are real”?—evidence against the involvement of the real body surface in sensations—phantom limbs, the visual blind spot—the need for a Mark-2 theory—an “inner model” as a substitute for the real body?—how this inner model could have evolved at the cortex through the short-circuiting of the sensory loop—“cerebral sentiments” as opposed to “corporeal” ones—what are cerebral sentiments now doing?
24 TIME PRESENT
What is meant by the claim that “to feel a sensation is to issue appropriate instructions for sentiments”?—why more has to be said about the nature of “instructions”—instructions are intentional and must have an anticipated outcome, but a train of nerve impulses per se cannot anticipate anything—the “extended present” and how actual and anticipated outcomes might overlap—reverberating feedback loops and their evolution in the brain—sensory activities become “instructions for themselves” phenomenology of the conscious present.
25 HURRAH!
The theory under review—conscious feeling emerges as a remarkable kind of intentional doing—a kind of doing that creates its own extended present outside of physical time, and of which the conscious subject is author, audience, and enjoyer, rolled into one.
26 HURRAH!—FOR THE OLD WAYS
Though most of the ingredients for a theory of consciousness are now in place, sensory quality is in danger of escaping—what has become of the “adverbial style” of sentiments once they no longer involve real bodily activity?—recourse to the idea of evolutionary conservatism—an architectural analogy—“skeuomorphs” in the evolution of design—the modal style of sentiments as a vestigial feature—an analogy with scripts—the question of genetic drift—the possibility that the styles of different species’ sensations might differ.
27 THE MIND MADE FLESH
The wider perspective—how far does consciousness extend in nature?—could any man-made artifact be conscious?—what evidence can we expect to get of consciousness in other minds?—how does the consciousness of other animals compare with ours?—what are the limits on what we ourselves can know?
28 WATER AND WINE
But is that all?—what else do people want?—metaphysical completeness—the status of a functionalist identity theory—Kripke on contingent and necessary identities—is there a possible world in which the theory would not hold?—if the theory has done its job, it has to hold.
29 BEING AND NOTHINGNESS
Finis
Notes
Index
ACKNOWLEDGMENTS
Ihave reason to thank many people for their help: in particular, Peter Bieri, Robert van Gulick, Nicolas Grahek, Ray Jackendoff, Marcel Kinsbourne, Ayla Kohn, Anthony Marcel, Jay Rosenberg, David Rosenthal, and Eckart Scheerer.
But there is one to whom I owe so much more than to any other that his name must stand alone. Daniel Dennett has been the kind of colleague whom everyone hopes for and almost no one gets: a patron, teacher, critic, co-adventurer, and friend. He encouraged me to start this book, gave me a base to do it from, scotched my doubts, raised others, and provided detailed criticism all along the way. Given Dennett’s own well-known position on a range of the issues that I cover here and on which he and I remain partly at odds, he may sometimes have thought he had introduced a cuckoo to his nest. So, all the more thanks to him.
In the course of writing, I held a Visiting Fellowship at Dennett’s Center for Cognitive Studies in the Department of Philosophy, Tufts University, and subsequently was a member of the “Mind and Brain Group” at the Center for InterDisciplinary Research (ZiF), University of Bielefeld. At a time when Britain has been making academic gypsies of us all, I am especially grateful to these foreign universities for accommodating me. For additional financial and material help I am indebted to the Kapor Foundation (which supported the Fellowship at Tufts), Alec Horsley, and to my publishers, and editor, Jenny Uglow.
READ ME
The indefinite article is not without its uses. While it would have been wrong to call this book “The History of the Mind,” I can call it “A History” without compunction. It is a partial history of a part of what constitutes the human mind: an evolutionary history of how sensory consciousness has come into the world and what it is doing there. But evolutionary history is the biggest part of history and sensory consciousness the best part of the mind.
There have been not a few—perhaps too many—books on mind, consciousness, and evolution published in the last few years (two of them by me). And, as shelves sag and appetites fade, I should explain what is different about this one.
It is different in being more old-fashioned than most. It has very little to say about computers, or artificial intelligence, or the so-called cognitive revolution in psychology. It refers hardly at all to recent developments in the neurosciences. It does not mention quantum theory, or fractals, or morphic fields. It makes no use of sociobiology. In fact, in many respects, this is a book that could have been written a hundred years ago. Only it wasn’t. It remains at the cutting edge of theory: but much of the cutting can still be done with a bare spade.
It is different in being more ambitious than most. It sets out not just to define the problem of consciousness but to solve it. After decades of misplaced optimism and subsequent disappointment many scientists and philosophers still see their primary task as being to identify the valley over the next mountain where the rainbow touches earth. But it is time we actually went digging for the crock of gold.
It is different in being about the real thing. Whereas in Consciousness Regained1 and The Inner Eye,2 I attempted to explain the nature of “conscious insight” into our feelings, here I return to the nature of feeling as such. Indeed here I totally ignore my earlier position and focus instead on consciousness as raw sensation. When J. M. Keynes was asked by a friend why he was so ready to reject some of his own previous ideas, he replied: “What else do you expect me to do, when I realize I was wrong?” In my own case it is not, I think, so much that I was wrong as that, in my earlier work, I came in at too high a level and left the fundamental problems unresolved.
Other writers about consciousness have tended, as I did previously, to concentrate on second-order mental faculties—“thoughts about feelings” and “thoughts about thoughts.” This bias is readily explicable. High-level skills, involving abstract reasoning, language, self-identity, social intelligence, and so on, are signs of human maturity, while raw feelings occur in brutes and babies. The former impress us and surprise us more than do the latter, they seem to require more evolutionary and individual work, they are the perquisites of a grown-up mind—and they are attractive to the theorist. When William Calvin, for example, writes (in another recent book on consciousness): “I really do mean consciousness in the sense of contemplating the past and forecasting the future, planning what to do tomorrow, feeling dismay when seeing a tragedy unfold, and narrating our life story,”3 or when Roger Penrose writes (in yet another), “it is the ability to divine or intuit truth from falsity in appropriate circumstances—to form inspired judgments—that is the hallmark of consciousness,”4 I understand their enthusiasm for explaining such remarkable human skills and wish them well. But first things first. Our life story is first of all the story of a sentient self or else no story—and this is a book about first things.
I have written the book in the form of a journey of discovery (which duplicates the way my own thinking has gone). The line of reasoning, though not haphazard, is serendipitous—taking advantage, as need arises, of biological evidence here, logical argument there, and pure speculation where nothing else suffices.
Although no author of a theory should hide behind the adage that “the journey not the arrival matters” I do believe that arrivals have very little meaning without journeys. In The Hitchhiker’s Guide to the Galaxy5 it emerges that the solution to the riddle of “life the universe and everything’’ is “forty-two.” Maybe it is. But who cares, if there is no explanation for how or why the answer happens to be 42? By itself, as a bare fact, the answer 42 is merely boring.
Could the solution to the problem of consciousness be boring? Though I say it myself, I suspect that if presented as a bare fact, yes, it could be (perhaps even should be). But when the solution is set in an evolutionary context, everything changes.
If I do not greatly delude myself, I have not only completely extricated the notions of Time, and Space . . but I trust, that I am about to do more—namely, that I shall be able to evolve all the five senses, that is, to deduce them from one sense & to state their growth, & the causes of their difference—& in this evolvement to solve the process of Life and Consciousness.
SAMUEL COLERIDGE, Letter to Thomas Poole, 18016
1
MIND AND BODY
Everything that is interesting in nature happens at the boundaries: the surface of the earth, the membrane of a cell, the moment of catastrophe, the start and finish of a life. The first and last pages of a book are the most difficult to write.
I am beginning this book on December 25, the anniversary of my father’s death. Perhaps I shall finish it by the time my own first child is born.
When my father died, I flew back from America to England and arrived home the next day. He was lying out in his bed in our farmhouse near Cambridge, proverbially asleep. The undertaker came and asked me to show him where the body was. Better, he said, that the family should remain in another room while he and his assistant carried “it” downstairs. The “it,” for me, was curiously relieving. My father was no longer there.
For seventy years my father had been a vessel of awareness, a bubble of conscious humanity carried along in the dark foam of insensate matter. For that bounded period he had been a subject to himself, an object to all others. His consciousness was self-contained. What was inside his mind was always outside ours. He had been the center of ideas. He had enjoyed the present tense of raw sensations. He had known what it is like to be a human being. But then, at last, the golden bowl was broken, the bubble burst. From there on, the inside/outside distinction disappeared; or rather there was no inside left to be.
At his funeral we read a passage from The Pilgrim’s Progress by John Bunyan: “When the day that he must go hence was come, many accompanied him to the river side, into which as he went he said, ‘Death where is thy sting?’ And as he went down deeper, he said, ‘Grave, where is thy victory?’ So he passed over, and all the trumpets sounded for him on the other side.”7
I thought at the same time of the Cypresse Grove, by William Drummond: “If two pilgrims, which have wandered some few miles together, have a heart’s grief when they are near to part, what must the sorrow be at the parting of two so loving friends and never-loathing lovers, as are the body and the soul?”8
There have been serious attempts, even in this century, to observe the “flight of the soul” by scientific measurement. Dr. Duncan Mac-Dougall wrote in the 1907 volume of the Journal of the American Society for Psychical Research that he had placed dying patients on a light bed, mounted on a set of carefully balanced scales. He reported sudden weight losses at the time of death of between three eighths and one and a half ounces for six different patients. When he carried out similar experiments with dying dogs, he observed no weight losses at death.9
MacDougall’s results have not been replicated. When death comes to a person, scarcely an atom need be gained or lost. It is just that the atoms that the person had been made of have been rearranged, and in their new arrangement they no longer constitute a person.
At a church service in Harlem two Sundays back, I heard a black preacher give a sermon on “Taking what is ours.” The question, he said, is “Is you is, or is you ain’t?” Hamlet put it differently: “To be, or not to be?” It is a question that allows no middle answer. Either it is like something to be oneself, or it is not. A person is, or he ain’t. The implications of the is are the subject matter of this book.
I have a big fish to fry. But I shall have to spend the first half of the book in catching it; and until I have done so I am reluctant to make any great claims about its size or weight. Its shape, however, I can tell you right away. It has the shape of the Mind-Body Problem.
The mind-body problem is the problem of explaining how states of consciousness arise in human brains. More specifically (and I shall have to be more specific in due time) it is the problem of explaining how subjective feelings arise in human brains.
The vocabulary I have to work with may not serve me well. “Subjective feeling,” already, is too vague a term. It is however the term commonly used, even in relatively technical discussions by philosophers, to capture the sense of what it is like to experience consciousness from the inside. Examples of subjective feelings are the sensed redness of a rose, the feeling of a shiver down one’s spine, the taste of Roquefort cheese.
Each of us experience such feelings in the “privacy” of our own consciousness, or so it seems. Their “quality” is transparent to us, although it is not something we could easily communicate to someone else; and because quality is so important, indeed intrinsic to the feeling, philosophers sometimes refer to subjective feelings simply as “qualia.” No one doubts that subjective feelings have quantitative aspects too: I might be able to tell you, for example, that one sensation of red was twice as intense as another. But what I could not tell you (if you did not already know) would be wherein the quality of redness lies.
Now here is the problem, as it emerges from three obvious facts of human life:
Fact 1 is the fact that when, for example, I bite my tongue I experience the subjective feeling of pain (and to remind myself of what that means, I am doing it now). This experience exists for me alone; and were I to try to tell you what it is like, I could do so only in the vaguest and most metaphorical of ways. My felt pain has an associated time (right now), an associated place (my tongue), an intensity (mild), and an affective tone (unpleasant), but in most other respects it seems beyond the scope of physical description. Indeed my pain, I would say, is not a part of the objective world, the world of physical material. In short it can hardly count as a physical event.
Fact 2 is the fact that at the same time as I bite my tongue there are related processes occurring in my brain. These processes comprise the activity of nerve cells. In principle (though not of course in practice) they could be observed by an independent scientist with access to the interior of my head; and were he to try to tell another scientist what my brain-based pain consists in, he would find the objective language of physics and chemistry entirely sufficient for his purpose. For him my brain-based pain would seem to belong no-where else than in the world of physical material. In short it is nothing other than a physical event.
Fact 3 is the fact that, so far as we know, Fact 1 wholly depends on Fact 2. In other words the subjective feeling is brought about by the brain processes (whatever precisely “brought about by” means).
The problem is to explain how and why and to what end this dependence of the nonphysical mind on the physical brain has come about.
It is a problem that has over the centuries filled philosophers with frustration, desperation, almost panic. Three hundred and fifty years ago René Descartes expressed his sense of helplessness: “So serious are the doubts into which I have been thrown that I can neither put them out of my mind nor see any way of resolving them. It feels as if I have fallen unexpectedly into a deep whirlpool which tumbles me around so that I can neither stand on the bottom nor swim up to the top.”10
Descartes’s own solution was to deny the obvious implication of Fact 3, and to plump for the hypothesis of dualism. Dualism asserts that the universe contains two very different kinds of stuff, mental stuff (of which subjective feelings are made) and physical stuff (of which brains are made), and that these exist semi-independently of one another. Thus in principle there could be minds without brains, and brains without minds. If and when these distinct entities meet and interact—as Descartes of course acknowledged that they do—it involves a handshake across a metaphysical divide.
The trouble with dualism is that it explains both too much and too little, and few philosophers have felt comfortable with it. More recently they have embraced various forms of monism. Monism asserts that there is in reality only one sort of stuff, of which both minds and brains are ultimately made. And in its most extreme form, physicalism, it claims that particular subjective feelings are actually identical to particular physical brain processes (in the same way that a bolt of lightning is identical to an electrical discharge in the air).
Few feel comfortable with this either. It would imply, for a start, that only carbon-based living organisms like ourselves (with carbon-based brains) could have conscious feelings anything like ours. And philosophers have been loath to deny consciousness in advance to other kinds of life forms with differently constituted brains. It would seem chauvinist, to say the least, to suppose that if humanoid creatures had evolved on a faraway planet, using different elements as building blocks, these individuals could have none of the subjective feelings we do—no matter how intelligently and sensitively they behaved. It might be true that they could not, but the truth is certainly not self-evident.
In any case, even if subjective feelings are as a matter of fact identical to physical states, this matter of fact would still cry out for explanation. If we were simply to acknowledge the identity we would have done nothing to dispel the sense of mystery about how it comes to be so. Analogies with lightning bolts would not help either. For in the case of lightning there really is no mystery: any competent physicist could predict that an electrical discharge in the atmosphere would under appropriate conditions produce the flash and bang. By contrast, no one could even begin to predict that the electrical activity of a brain would produce the subjective feeling of tasting cheese.
Samuel Johnson wrote in Rasselas in 1759: “Matter can differ from matter only in form, bulk, density, motion and direction of motion: to which of these, however varied or combined, can consciousness be annexed? To be round or square, to be solid or fluid, to be great or little, to be moved slowly or swiftly one way or another, are modes of material existence, all equally alien from the nature of cogitation.”11 And for many modern commentators the same anxieties persist. Colin McGinn, the British philosopher, has written recently: “Somehow, we feel, the water of the physical brain is turned into the wine of consciousness, but we draw a total blank on the nature of this conversion. Neural transmissions just seem like the wrong kind of materials with which to bring consciousness into the world. The mind-body problem is the problem of understanding how the miracle is wrought.”12
McGinn’s unhappy conclusion is that the problem is probably unsolvable: either there actually is not a solution, or, if there is one, human intelligence must always be too limited to grasp it.
Some kinds of problem are unsolvable in principle. There is no solution, for example, to the problem of how to get a quart into a pint pot, or to fit a left hand to a right-hand glove, or (as it happens) to turn water into wine. If the mind-body problem were that kind of a problem, there would be little point pursuing it.
But before we draw any such analogy, we should note an interesting difference between the problems of getting a quart into a pint pot and of getting consciousness into the brain: which is that, while the former has never been known to occur, the latter occurs all the time. If the conversion of the water of the physical brain into the wine of consciousness is a miracle, it is one of those everyday miracles to which the word “miracle” by definition should not apply.
That being so, we should be careful how we set up the mind-body problem, lest without realizing it we render it not just a difficult problem but one that appears logically intractable.
Gottfried Leibniz in his Monadology in 1714 imagined someone walking around a brain, as a factory inspector might walk around a flour mill: “It must be confessed, moreover, that perception and that which depends on it are inexplicable by mechanical causes, that is, by figures and motions. And, supposing that there were a machine so constructed as to think, feel and have perception, we could conceive of it as enlarged and yet preserving the same proportions, so that we might enter into it as into a mill. And this granted, we should only find on visiting it, pieces which push one against another, but never anything by which to explain perception.”13
The metaphor is a compelling one, but if you think about it, it has an obvious flaw. Leibniz took the mill to exemplify the bottom line of physical reality. But he might have used the same example to quite different effect. For note that a mill is not simply a physical object. Most importantly it is a mill, a machine for grinding grain to yield flour for bread; it is a place of employment; it is a source of wealth. In fact, for the Miller of Dee in the song: “I live by my mill, she is to me both parent, child and wife.” Someone who visited the mill and found only pieces which push against each other would not be able to explain any of those properties either. But then that would be because the visitor was falling into the commonsense trap of assuming that the first way something strikes him must be all there is to it: he would be using the wrong level of description.
I once gave a class lecture in which I brought with me a box with two things in it. I drummed on them with a ruler, rat-a-tat-tat. I asked the students to guess what was in the box. “Hollow objects.” I let them have a glimpse. “Bones.” “Human skulls.” One was smaller than the other. “Man and woman’s skulls.” Taking the skulls from the box, I explained that these were the skulls of American Indians, stolen from a grave. “Put them back.” I explained that they were probably man and wife, a young couple who had died together and been buried together; I gave them names and I placed the faces cheek to cheek, Hiawatha and Minnehaha. “That’s horrible”
The lesson was that a couple of hollow objects made chiefly of lime can also at another level of description be the relics of two lovers; moreover that what someone does with them can be either a casual entertainment or a gross insult. Different levels of description need have nothing much in common.
Now, what is true for a mill or a skull is certain to be even more true for a highly evolved functional mechanism like a brain. In one sense brains are unquestionably physical objects, which can be described reductively in terms of their material parts. But that is surely not the only way of representing them, nor is it necessarily the most revealing way. What may be required, in order to provide a better clue to how mental activity comes into being, is a way of representing what the brain does over time as distinct from what it is from moment to moment.
One possibility, for example, would be to think of brains as computing machines or logic engines, so that the properties they have for us are not so much physical as mathematical. Thus a brain could be characterized as a device that takes in “information” and “processes” it to yield further information (it certainly does do that, if that is how we choose to describe it); and it could be said that what matters is the mathematical relation between input and output. In that case particular subjective feelings would be identical not to particular physical brain processes but rather to the particular logical operations being performed.
The theory that mental states in general are nothing other than mathematically defined computational states has come to be known as functionalism. It has been taken up enthusiastically by several contemporary philosophers. William Lycan, for example, wrote in a recent book that this is “the only positive doctrine in all of philosophy that I am prepared (if not licensed) to kill for.”14 But while many others would agree that there could be an equivalence between computational states and certain sorts of mental processes, they draw the line at conscious mental processes, and draw it more firmly still at conscious awareness of subjective feelings.
It is certainly a strange idea: that states of consciousness correspond to logical rather than material states of the brain. It seems especially strange when we realize that, if it is right, these same logical states could exist in an inanimate machine and that the machine (whatever it was made of) would thereby have conscious feelings.
The idea is too strange for some. To quote McGinn again: “You can’t get the qualitative content’ of conscious experience—seeing red, feeling a pain, etc.—out of computations in the nervous system.”15 Or to quote Ray Jackendoff, author of Consciousness and the Computational Mind: “I find it every bit as incoherent to speak of conscious experience as a flow of information as to speak of it as a collection of neural firings”16
Maybe, however, it is just that we do not yet know enough about the nature of the thing that the nervous system must be computing, and when we do it will not seem such a miracle.
Well, we shall see . But not before we have a better fix on what the “mind” side of the mind-body problem is. And this will require a major rethink—or repair—of widely held assumptions about what minds are for. Although my aim is indeed to explain “consciousness” in sentient human beings, there is much that has first to be said about being human, and before this much that has to be said about being sentient.
2
“PUZZLING WORK”: AN ASIDE ABOUT LANGUAGE
Though I have hardly begun, I want to stop and make some prophylactic comments about the use of words. In what I have already written, and more so in what is to come, several of the key terms are put in quotation marks or emphasized, a sure sign that the words in question are not quite right. Sometimes, as J. Alfred Prufrock laments in T. S. Eliot’s poem, it seems that:
It is impossible to say just what I mean!
But as if a magic lantern threw the nerves in patterns on a screen.17
Yet if it is true that our linguistic resources for talking about the mind are so poorly developed, this might be taken to imply that there is something seriously wrong with the whole enterprise. After all, human beings have been talking around and about these questions for a long, long time. If it is still so hard to find the right words to describe such seemingly essential notions as mind and consciousness, perhaps it means that these notions are not so essential after all.
There is a strong tradition in twentieth-century philosophy to the effect that if and when we cannot say exactly what we mean, we probably do not mean anything worth saying. “Anything that can be said,” Ludwig Wittgenstein wrote, “can be said clearly.” But the situation is not really so clear-cut. Wittgenstein’s Cambridge colleague C. D. Broad claimed that “clarity is not enough.” He meant that speaking clearly is no guarantee of speaking sense—that clarity, even if it is necessary, is not sufficient. But maybe total clarity is not necessary either. As we all know, a great many things that human beings actually do say to each other are not said clearly. And yet, it seems, we succeed in conveying most of what we want to convey most of the time.
We should not take a Panglossian view of human language. Dr. Pangloss’s maxim was that “All is for the best, in the best of all possible worlds.” He would no doubt have considered that everything about our language is already as good as it could possibly be. But he would surely have been wrong. For just as an individual child has to acquire a vocabulary in the course of growing up, so does a human culture; and it may well be that in some areas of discourse our linguistic culture is still at the infant stage.
A revealing example of linguistic immaturity occurs with Plato, who it seems had great difficulty in speaking about numbers. In The Republic Socrates is discussing how the Guardians of the state should organize a breeding program for the citizens: “Though the Rulers you have trained for your city are wise, reason and perception will not always enable them to hit on the right and wrong times for breeding; some times they will miss them and then children will be begotten amiss.” Fortunately, says Socrates, it can all be worked out by arithmetic: “For the human creature the number [of gestation] is the first in which root and square multiplications (comprising three dimensions and four limits) of basic numbers, which make like and unlike, and which increase and decrease, produce a final result in completely commensurate terms.”18
If this is all Greek to you, you are in good company, for even early classical commentators could not make out what was meant. It is now generally agreed that the number in question—“Plato’s number”—was 216; and 216 days is 7 months, which was regarded by the Greeks as the minimum period of gestation (normal gestation being calculated as 216 + 3 x 4 x 5 = 276).
Now, 216 is 6 cubed, and it is also equal to 3 cubed + 4 cubed + 5 cubed. It was this property that Plato was apparently trying to specify. But although he must have known about “cubing”—have understood intuitively its mathematical significance—he did not have a word for it. And the best he could do, so scholars suggest, was to employ the clumsy expression “root and square multiplications (comprising three dimensions and four limits).”
It may seem to us now almost bizarre that Plato of all people should have been lost for a way of expressing such a simple concept as “taking the third power.” Every modern schoolchild can do better. But, however that may be, no one presumably would want to claim that Plato’s linguistic embarrassment could ever have implied that “cubing” was—or is—an idea about which it would have been better not to have said anything at all.
The lesson I would draw is that perhaps we ourselves are now in the same position with respect to the language we have at our disposal for talking about mind and consciousness. At this stage in our cultural development there are still things we can appreciate intuitively which as yet we have no good way of putting into words.
The problem becomes especially obvious when one national language has resources that another lacks. There is a famous essay by the philosopher Thomas Nagel that is entitled “What Is It Like to Be a Bat?”19 In French this has been translated (with an apologetic note from the translator) as “Quel effet cela fait d’etre une chauve-souris?”20—literally “What effect (or impression) does it make to be a bat?” Since the point of Nagel’s essay is to argue precisely that the subjective experience of a bat cannot be described in terms of its observable effects, there would seem to be a real danger that French readers will not entirely get his message. Yet who doubts that French speakers have the concept—if only it can be addressed—of what in English we express as “what it’s like to be ”?
This is one of the problems with language. But there is another that is nearly the opposite. While sometimes we are lost for words, at other times the words come all too easily. The fact that a word or phrase exists in our language and is available for use is no guarantee that it can do a useful job. Certain words are, as it were, impostors, that promise much more than they deliver (in fact there are those who would argue that “what it’s like to be . . ”is just such a case!).
One of the best-known examples is the word “phlogiston,” coined in the eighteenth century to refer to the hypothetical material with negative mass that was supposed to be released from combustible bodies on burning. But we might think too of “elan vital,” “animal magnetism,” “telepathy,” not to mention a host of words with more impressive pedigrees such as “Father Christmas,” “the Loch Ness Monster,” and “nuclear deterrence.”
George Eliot wrote in her journal for 1856: “I have never before longed so much to know the names of things. The desire is part of the tendency that is now growing in me to escape from all vagueness and inaccuracy into the daylight of distinct vivid ideas. The mere fact of naming an object tends to give definiteness to our conception of it.”21 But the mere fact that naming something tends to give definiteness to our conception of it can cut both ways. Once we have a word for something it is easy to suppose that ipso facto the thing named is a distinctive entity.
The Great Train Robbery in England in the 1960s provides a comic illustration. The police had made no progress whatever in solving the crime. Eventually the head of Scotland Yard called a news conference where he announced, with evident satisfaction, that he could now reveal that “there was a Brain behind the robbery.” His statement evoked a mocking comment from the French newspaper Le Monde: “Tout est explique. Un Cerveau, c’est quelque chose!” But of course nothing was “explique,” since the “Cerveau” was not “quelque chose!” at all. Scotland Yard’s naming of the Brain was no more than a convenient way of explaining away their inability to catch the robbers.
Taken together, these two problems with language create a kind of double jeopardy for discussions of the mind: there are likely to be certain areas where, as it were, the words play hard to get, and others where they sing a Siren song. One of George Eliot’s characters, Mr. Tulliver, put the point nicely in conversation with his wife: “No, no Bessy I meant [what I said] to stand for summat else; but never mind—it’s puzzling work, talking is.”22
To illustrate just how puzzling is the work of talking about mind, consider several recent statements about “consciousness”:
“Consciousness is the greatest invention in the history of life; it has allowed life to become aware of itself.” [Stephen Jay Gould (biologist)]23
“Conscious awareness is a conditional property of the reality model in its tripartite form. It may be said to be the subjective aspect of the continuing re-presentation of a temporally stabilized informational display within which multilateral processing of an issue can occur.” [John Crook (ethologist)]24
“In all the contexts in which it tends to be deployed, the term “conscious” and its cognates are for scientific purposes both unhelpful and unnecessary.” [Kathleen Wilkes (philosopher)]25
“Reference to consciousness in psychological science is demanded, legitimate, and necessary. It is demanded since consciousness is a central (if not the central) aspect of mental life. It is legitimate because there are as reasonable grounds for identifying consciousness as there are for identifying other psychological constructs. It is necessary since it has explanatory value, and since there are grounds for positing that it has causal status.” [Anthony Marcel (psychologist)]26
“I find that I have no clear conception what people are talking about when they talk about consciousness’ or phenomenal awareness. ” [Alan Allport (psychologist)]27
To which I would add the famous passage from William James, in 1904: “ ‘Consciousness’ is the name of a non-entity, and has no right to a place among first principles. Those who still cling to it are clinging to a mere echo, the faint rumor left behind by the disappearing soul, upon the air of philosophy. It seems to me that the hour is ripe for it to be openly and universally discarded.”28
James actually went further. “Breath,” he wrote, “moving outwards, between the glottis and the nostrils, is, I am persuaded, the essence out of which philosophers have constructed the entity known to them as consciousness.” That the man who a few years earlier had popularized the idea of the “stream of consciousness” in his Principles of Psychology should have become so hostile to the very term suggests an unusual degree of disillusionment.
Perhaps James would have liked the remark of an American schoolboy, reported in a recent edition of The Boston Globe. The boy had been asked to write an essay about vacuums: “Vacuums,” he said, “are nothings. We only mention them to let them know we know they’re there.”29
He might have been amused too by the report of a 1960s Loch Ness investigator, Maurice Burton. “From my own experience and those of other observers, there is one statement more true than another: it is that the Loch Ness Monster comes to the surface with surprising infrequency.”30
After the Loch Ness Monster had supposedly been photographed by an underwater camera, the naturalist Sir Peter Scott suggested in the journal Nature that it now merited a scientific name: Nessiteras rhombopteryx—Ness dweller with rhomboidal fins.31 By an unhappy accident, the name was an anagram of “monster hoax by Sir Peter S.”
There may well prove to be problems about calling consciousness by name. But they should not prove insuperable. For, if there is one statement that, if not more true than another, is nonetheless true, it is that consciousness comes to the surface with surprising frequency.
3
WHAT HAPPENED IN HISTORY: THE INSIDE STORY
There are several ways to catch a fish (if not a monster). You can drag a net across the river, and pull in everything there is: but this way you get the weeds, the frogs, and old boots too. You can put a worm on a hook, and cast it into a likely-looking pool: but this way you risk choosing the wrong pool or a day when the fish are just not feeding. Or (so an old Scotsman told me) you can tickle it: you walk stealthily along the riverbank until you see your fish hanging in the water just upstream; you lean down from the bank and lower your fingers ever so slowly under the fish’s belly; you stroke it; and then (so he said) the fish just lets you lift it out.
I believe the way to catch consciousness will be to tickle it. That is to say we should discover where it is lying, approach it slowly, and then charm it into our hands.