I have written this book," Gerald Edelman brazenly announces at the opening of Bright Air, Brilliant Fire: On the Matter of the Mind, "because I think its subject is the most important one imaginable." Since his book is about the nature of human consciousness, that might be nothing more than cutely obvious. But Edelman is not playing obvious, and he is far from alone in believing that something has recently cracked and given in what used to be the wall of mystery surrounding consciousness. Building on a generation's worth of studies of brain physiology and on the creation of computers in the last decade and a half sophisticated enough to simulate thinking, Edelman—together with Patricia and Paul Churchland, Daniel Dennett, John Searle, and Francis Crick, to name only the most well-known—have suddenly thrust onto center stage an unsettling series of solutions to the mystery of human self-awareness, our subjective experience of being alive and personal, of the divine spark, if you will.

These solutions are far from unanimous in their details, but they are all agreed on one very basic point: What we call "consciousness" is purely a material process. Consciousness is not the evidence of a "mind" substance as apart from "body" substance; still less is "consciousness" the activity of a spirit or soul inside our physical bodies. "We are at the beginning of the neuroscientific revolution," Edelman buoyantly declares, "a prelude to the largest possible scientific revolution, one with inevitable and important social consequences." Indeed we are, and while Christians are mostly consumed with opening yet newer rounds in their century-and-a-half-old war with Charles Darwin, they have scarcely the faintest idea that the new consciousness enthusiasm is by far the greater threat to the integrity of Christian belief.

What is peculiar about what Edelman calls "the neuroscientific revolution" is that it is really not a new business at all, but merely a long-deferred one. Three hundred years ago, the achievements of Galileo, Newton, and the Scientific Revolution knocked down all explanations of the physical universe to the operation of laws on material substances. They might have tried to reduce the inner world of human experience to the same level if the brain had been as easily observable as the orbit of the moon. But that, as RenŽ Descartes delighted in showing in his Meditations on First Philosophy in 1641, was not the case, a difficulty that allowed Descartes to cut one of the greatest deals in Western philosophy. In exchange for conceding that the world outside the human consciousness was nothing but material substance (and therefore the proper domain of the scientists), Descartes insisted on keeping the subjective world of the consciousness as the location of spiritual substance, or the soul. It was, in effect, the first great land-for-peace swap: the scientists would be allowed to reduce everything outside the mind to simple physical laws and material substance provided they acknowledged that personal consciousness was the product of an entirely different kind of spiritual substance that obeyed spiritual and moral laws and provided direct contact with God.

And this was not, on the whole, a bad bargain, either. The scientists had more than enough to explore in the outer world to keep them occupied for a couple hundred years, and the theologians could be content that, whatever might be true in the physical world, the irreducibility of the mind to material substance was proof of the existence of the soul, and beyond that, of God.

This zoning-off of the mind from the scientists was helped by the fact that human consciousness really did turn out to be a difficult subject to get under scientific observation. Even defining consciousness is not easy since our own consciousness is the most obvious, direct, and familiar thing we deal with every day, but also the hardest to analyze and report upon. To study one's own consciousness is like trying to be conscious of one's consciousness: how can you step back and look at the very thing which permits you to step back and look in the first place? Not only is it difficult to be objective about one's own consciousness, it is impossible to simulate someone else's. Objectively, we can all recognize the sharpness of a thorn, but only the person who is pricked by it feels pain.

There were a persistent few who kept picking at the problem, as Israel Rosenfield shows in The Strange, Familiar, and Forgotten: An Anatomy of Consciousness, but almost all of them came at it as critics of Descartes, eager to reduce consciousness to a physiological shadow of the brain and get rid of the last toehold of spiritual substance. Julien de La Mettrie in 1747 asserted that thought and consciousness were no evidence of spiritual substance but were only properties or functions of brain matter. The pioneer German neurologist Franz Gall linked certain kinds of thought to specific physical areas of the brain, and in 1861 Paul Broca staged a dramatic public demonstration of how damage to a particular area of the brain's left hemisphere (now known as Broca's Area) rendered certain kinds of speech impossible.

But neither Broca nor Gall attracted much interest outside of their specialties. Popular attention was riveted instead on Sigmund Freud's pursuits of the mind's pathologies, which led him and most of this century's students of the mind away from the study of consciousness and into the more dubious realms of the unconscious.

In the United States, the popular dominance of pragmatism in American philosophy also diverted interest away from study of the mind and into ways of understanding and manipulating behavior. Neither the Freudians nor the behaviorists were particularly friendly to any notions of a soul, but at least none of them spent much time trying to prove that it didn't exist.

This began to change after World War II, and one can almost pinpoint the moment when consciousness once again became a direct scientific target: the conceptualization by Alan Turing of the basic model of the computer and John von Neumann's conclusion that the computations performed by complex, integrated computers are like the functions of the brain. Hence, the brain should be understood, not as the residence of the soul, but as the hardware of a computational device. The proof of this, which became known as the Turing test, was maniacally simple: Any logical function, mathematical or otherwise, can be performed on a Turing machine; complex logical functions merely require the development of more complex Turing machines to copy them artificially; eventually, a universal Turing machine will be able to perform all the logical functions of a human being, and in such a way that an observer will not be able to distinguish between the work done by the human being and the work done by the computer. At that point, the computer will have achieved the same mind state as the human being; or, to put it another way, we will discover that human consciousness is nothing different from the high-level operations of a Turing machine.

This opened a direct route toward creating computers so sophisticated that they could beat grandmasters at chess. What was less noticeable at first was that this also opened the direct route to overthrowing Descartes' dualism and demonstrating that consciousness, instead of being the proof of spiritual substance in human beings, is only the by-product of computation—at best, the software of a mental Turing machine.

Although proposals for equating brains and computers first surfaced in the 1940s, the real starting date for what Edelman calls the "neuroscientific revolution" is 1986 and the publication of Patricia Churchland's Neurophilosophy: Toward a Unified Science of the Mind/Brain. Churchland's book promised to "change profoundly" not only our understanding of the working of the brain but "therewith our epistemology." Even though subsequent work on the brain squeezed Churchland to concede (in The Computational Brain, which she wrote with Terry Sejnowski in 1992) that the brain was a good deal more complicated than an ordinary computer, it remained her basic contention that consciousness was really only computation and that "psychological processes are in fact processes of the physical brain, not, as Descartes concluded, processes of a nonphysical soul or mind."

That kind of blunt combativeness earned Churchland an immediate sit-up audience. But not even Churchland could match the free-wheeling feistiness of Daniel Dennett of mit, where the nation's most advanced center for studies of artificial computer-modeled intelligence was headquartered in the early 1980s. Dennett might be better known for the pristine Darwinian fundamentalism he defended in his best-selling Darwin's Dangerous Idea: Evolution and the Meanings of Life (1995), but he has actually devoted most of his career as a philosopher to problems of the brain and knowledge. "My first year in college, I read Descartes' Meditations and was hooked on the mind-body problem," Dennett wrote in Consciousness Explained in 1991. "How on earth could my thoughts and feelings fit in the same world with the nerve cells and molecules that made up my brain?" The answer for Dennett was found in computation: computers are brains, virtually, and the process of computation is a computer's version of consciousness. At the same time, what we experience as consciousness is a virtual equivalent of the brain's performance as a computer. "Anyone or anything that has such a virtual machine as its control system is conscious in the fullest sense, and is conscious because it has such a virtual machine."

What Pat Churchland likes to state as an unadorned assertion, Dennett clothes in rhetorical provocation, and there is no philosopher writing in America today who has Dennett's gift for the jewellike explanation or the wickedly well-timed argument. He jeers at the notion that consciousness is a resident or a location in the brain—that it is a "Cartesian Theater" where information from the material world is assembled and evaluated for thought and action. Instead, the brain operates something like a word processor, creating what Dennett calls "multiple drafts" in which good ideas or "good tricks" survive to produce design enhancements in the larger organism. Draft for draft, "conscious human minds are more-or-less serial virtual machines."

In that respect, not only is consciousness not a Cartesian Theater, but there is no subjectivity, no intentionality, and in fact nothing that we usually call consciousness in the brain at all. The only thing that can be called consciousness is the brain's program, and it "can best be understood as the operation of a 'von Neumannesque' virtual machine." In effect, Dennett's solution to any dualism of consciousness and brain is to eliminate consciousness, or at least eliminate it as anything more genuinely subjective than a computer program. This, as Dennett well knew, would draw immediate fire from critics who believed that Dennett was bluffing, and that he would back down the moment it was pointed out that this would reduce human beings to the equivalent of zombies. He never blinked. "We're all zombies," he announced—highly complex zombies, of course, but more near kin to zombies than to Descartes' dualist composite of material and spiritual. What we imagine to be the activity of a unique nonmaterial substance inside us (or inside our heads) that produces our consciousness is really a mistake, a sort of primitive folk-psychology belief like the flat Earth.

The problem is that, if consciousness really is an illusion, it is the greatest mistake human beings have ever made— a mistake so colossal that many of the neuroscientists and neurophilosophers in the consciousness camp who otherwise share Churchland's and Dennett's eagerness to reduce mind to matter are openly reluctant to make the computer the matter it gets reduced to. John Searle, who yields nothing to Dennett in combativeness, dismisses computational models of consciousness as ridiculous.

Suppose (asks Searle) I find myself in a locked room, into which questions in the form of Chinese characters are being fed; I am equipped with a handbook which tells me that, whenever a certain character is fed into the room, I am to feed a certain other one out as the answer to the question. Much as this might actually offer a fair imitation of conversational Chinese, I never actually understand Chinese. All I do is perform the necessary algorithm for processing Chinese characters. This "Chinese Room," Searle insists, is a fairly good model for how a Turing machine operates, but it also underscores what a computer can never do: it can never understand Chinese. The computationalists have mistaken syntax (an algorithmic process computers can perform very well) for semantics, which only conscious humans can experience.

Searle's "Chinese Room" was never intended as a defense of Descartes or of the soul. In the broadest sense, Searle actually agrees with Dennett and Churchland that "mental phenomena are caused by neurophysiological processes in the brain and are themselves features of the brain." It's simply that, for Searle, consciousness does not function like computation. Consciousness involves properties—such as intentionality, time, distinguishing the self from what is nonself—which have no corresponding features in a computer.

But putting the argument this way still leaves Searle open to the charge that he is really a closet dualist after all. Even if our consciousness is not the representative of a substance different from our bodies, it still involves properties that distinguish it from every other material substance in our bodies, and so we still get a wall of separation between mind and body, consciousness and brain. Searle protests that this is not at all what he wants, that consciousness should be regarded as a by-product of brain activity just like "growth, digestion, or the secretion of bile." No use: for Searle's critics (and over a hundred attacks on the "Chinese Room" argument have appeared since Searle first published it), any division of consciousness from the brain is dualism, and dualism is the enemy of all properly credentialed science.

In his less antagonistic moments, Searle is willing to see the computationalists as an amiable but overenthusiastic spinoff of interest in artificial intelligence. But as a materialist himself, he resents the tendency of Churchland and Dennett to cast all noncomputationalists as secret Cartesians unless they are willing to deny the existence of consciousness as a unique state and embrace the computer. "Earlier materialists argued that there aren't any such things as separate mental phenomena, because mental phenomena are identical with brain states," Searle complained in The Rediscovery of the Mind in 1992, but what Dennett and Churchland want to argue is "that there aren't any such things as separate mental phenomena" in the first place. Computationalism, which he describes as "eliminative materialism" or "strong artificial intelligence" (or simply "Strong ai"), is simply "the view that mental states don't exist at all."

The same skepticism about computationalism flavors three of the most important observers of the consciousness revival besides Searle—Francis Crick, Gerald Edelman, and Roger Penrose. Crick came to consciousness studies through his interest in vision, and his name recognition as the codiscoverer of the DNA double helix may be the greatest publicity asset that consciousness studies have. Or maybe not: His 1994 book on consciousness, with the sensational title The Astonishing Hypothesis: The Scientific Search for the Soul, belied the pretensions of its title on the very first page when Crick explained that "I do not suggest a crisp solution to the problem." Indeed he does not. His "astonishing hypothesis" is simply that "our identities are nothing more than an assembly of nerve cells," a hypothesis that ceased to be astonishing quite some time ago. What is genuinely astonishing in Crick's book is Crick's own naivte. He is certain (as Searle cautiously is not) that consciousness arises in the thalamus at moments when the firing of neurons achieves a certain speed and rhythm, and that mental phenomena like free will can be neatly "located in or near the anterior cingulate sulcus."

But if Crick is amateurishly simplistic in his eagerness, he still shares with Searle two basic propositions: that there is no soul or spiritual substance that underlies or constitutes consciousness ("the idea that man has a disembodied soul is as unnecessary as the old idea that there was a Life Force") and that consciousness is a product of biological materialism, not computational materialism. ("A brain does not look even a little bit like a general-purpose computer," Crick snorts. "Faced with tasks that ordinary humans can do in a rapid and effortless way, such as seeing objects and understanding their significance, even the most modern computers fail.")

Gerald Edelman's Bright Air, Brilliant Fire and The Remembered Present: A Biological Theory of Consciousness have none of Crick's credulity while still underscoring the same point about the biological sources of consciousness. Edelman shies away from Crick's cheerful confidence that he can pin consciousness down to certain select neurons, preferring to speak of consciousness as a dynamic phenomenon, a relationship between "neuronal maps" in the brain or a conversation between differing orders of neurons. Edelman is also just as strongly convinced of the folly of computationalism. The brain "is not a computer and the world is not a piece of computer tape," and computationalism is a piece of "silliness" that has arisen "from the analogy between thinking and logic." Edelman has, moreover, a mathematician's argument to throw back at computationalism, Kurt Godel's "incompleteness" theorem, which establishes that no system of algorithms is sufficient of itself to prove its own truth. If minds were computers and consciousness were computation, then by Godel's theorem the system could never be aware of itself—but self-awareness is the pith of consciousness if ever anything was. Hence, minds cannot be like computers.

Edelman's portrait of consciousness as a kind of discourse seems to have a particularly strong appeal for philosophers and historians, for whom discourse is their daily bread. Israel Rosenfield, trained as a physician but a professor of history at the City University of New York, insists that consciousness "has to be relational" and that it "is this relation that creates a sense of self." Rosenfield is critical, not only of the computationalists, but also of the quick-trigger materialism of many neurologists and psychologists going back to Gall and Broca who believe that damage to specific material locations in the brain has to result in specific alterations in consciousness. Understanding consciousness as a relation means, for Rosenfield, that it is not possible to sustain brain damage in one place in the brain "without profound alterations in the entire structure of an individual's knowledge." Fred Dretske, chair of the philosophy department at Stanford, also makes a case (in Naturalizing the Mind) for consciousness as a relationship, not so much between physical points in the brain as between the brain's representations, which he insists are just as material and "objectively determinable as are the biological functions of bodily organs."

But biological explanations of consciousness—even when redefined as neuronal or representational relations— still call for the denial of a great deal of what intuition (or "common sense" or whatever) tells us about the uniqueness and subjectivity of consciousness. Such denial does not come readily to Roger Penrose, who is a mathematician rather than a biologist like Crick or Edelman, and who finds that Godel's theorem does more than merely discomfit the computationalists. In Shadows of the Mind: A Search for the Missing Science of Consciousness, Penrose admonishes his consciousness colleagues that Godel's theorem demonstrates that "human insight lies" not only "beyond computable procedures" but "beyond formal argument" as well. Biology, as much as computers, will fail to describe consciousness because consciousness, in all likelihood, operates in ways that transcend both.

Penrose believes that, if an answer to consciousness is likely to come from any source, it will only come in the future and from the development of quantum mechanics. "The physics of ordinary matter seems, at first sight at least, to allow no room for … non-computable behaviour," but Penrose is confident that "it is only the arrogance of our present age that leads so many to believe that we now know all the basic principles that can underlie all the subtleties of biological action." Consciousness is too complex to explain in any terms less than a new physics.

But whether it is biology or physics that does the explaining, all of the noncomputationalists still end up on at least this much common ground with Dennett and Churchland: consciousness is a natural process, a function of material substance; there is no soul, nor any other spiritual substance; and at death it all disappears. Searle, Crick, Edelman, and Penrose rescue us from computational zombiedom, but to what end? "With the death of each individual, that particular memory and consciousness is lost," Gerald Edelman writes, with an evident tinge of wistfulness. "There is, as such, no individual immortality."

One does not have to be a Christian to find ominous regions of fault in the new consciousness studies. A truculent band of dissenters within the ranks of the consciousness mavens, headed by Colin McGinn and nicknamed "the New Mysterians," insists that the experience of consciousness is so subjective that there is no secure way of drawing connections between brain physiology and conscious states. McGinn, invoking a classic argument by Thomas Nagel on the impossibility of humans conceptualizing the cognitive experience of a bat, warns that consciousness studies cannot penetrate the nature of consciousness itself without a "radical conceptual innovation (which I have argued is probably beyond us)."

David Chalmers, writing in Scientific American in 1995, suggests that maybe consciousness just happens, and cannot be reduced to either physics or biology. Maybe, even Roger Penrose allows, consciousness "might indeed require some kind of act of God—and … cannot be explained in terms of that science which has become so successful in the description of the inanimate world."

We have learned too much in the last half-century about imperialism to imagine that the imperialism of science will have any better results, and the voices that suggest at least looking before leaping over consciousness have a good deal of merit to them. That this caution is so quickly disregarded in the consciousness books rouses suspicion that there may be other agendas driving the popularity of consciousness studies.

It is curious that although the consciousness literature has the aura of "neuroscience" about it, a number of the consciousness books form a suggestive—and I don't think altogether accidental—counterpart to the rage for literary theory in the 1990s. If the center of literary theory has been the uncertainty of narrative selves and the production of "selves" purely as performances or interpretations, then nothing comes closer to that in physiological terms than a consciousness that has no substantial integrity of its own. Perhaps it is no accident again that Descartes is the philosopher that literary theory loves to hate.

More troubling are the implications for ethics and action posed by the consciousness studies. Gerald Edelman, with what sounds like real anguish, warns that "under present machine models of the mind," questions of ethics and morals become "a problem of major proportions, for under such models it is easy to reject a human being or to exploit a person as simply another machine." If the last refuge of the soul turns out not to be a refuge at all—if even our consciousness is itself no more privileged in substance than our digestion—then no good reason exists apart from cultural opinion not to indulge whatever things power gives us the means to do to each other.

This turns out to be exactly what some of the consciousness studies recommend. Almost as if in a demonic echo of Edelman's dilemma, Daniel Dennett cheerfully catalogues as "myths" such concerns as the "sanctity of life, or of consciousness." Francis Crick, whose indifference to the clumsiness of an argument suffers nothing when transferred from neurology to ethics, seems genuinely surprised in The Astonishing Hypothesis that anyone should raise ethical questions about a desire to experiment on human brains (and why not, when consciousness is only a matter of rioting neurons?) and he quietly applauds one colleague who "wisely did not embark on his experiments on consciousness in alert people until he had obtained the security of academic tenure."

Only a little less ominous is the sharply deterministic bent of virtually all of the consciousness literature. Both Crick and Dennett feel there is little point in talking about free will or moral responsibility as it has been usually understood; Penrose would like to defer "the profound issue (or the 'illusion'?) of our free wills" for consideration in "the future"; Searle and Edelman are willing to espouse some form of free will, but even then, it is only to "some degree." Clothing consciousness studies with ethical restraint, as Edelman puts it with substantial understatement, "is one of the largest challenges of our time."

If so, it is remarkable for how little Christian thinkers have risen to meet it. In a review in these pages (Books & Culture, January/February 1996) of Roger Penrose and Patricia Churchland's husband, Paul Churchland (a professor of philosophy at the University of California, San Diego, and an associate of the Salk Institute), William Hasker joined in the attack on dualism by suggesting that "Mind-body dualists, who think the mind or soul is not fundamentally dependent on the brain, owe us a plausible account of these functional dependencies—an account that, so far as I know, is not yet forthcoming."

Well, if the soul isn't in some very fundamental way independent of the brain, it would be even more important to have a plausible account of just what part of the soul is lost to death when the brain dies. Hasker's bland and accommodating observation that "the view that the mind is somehow produced or generated by the brain is not in conflict with any essential Christian doctrine, including the belief in eternal life," actually avoids an endorsement of materialism only by dangling on the qualifier somehow. And the suggestion by Hasker that such a reduction simply reminds us "more seriously than has generally been done the truth that we are created from the dust of the earth" misses entirely the even more serious reminder that God breathed into us an immortal soul, and that the two get confused at our peril.

But Hasker is a philosopher, and a little theological blandness can be forgiven. From the theologians there is not only deafening silence, but not even much recognition that a problem is being brewed under their noses. If we are being saved in both body and soul, hadn't we better secure a reasonably good grip on what we mean by the soul if the very idea of salvation is to remain coherent? Where is the evangelical theologian writing on the soul?

One place where such an answer might begin is to question what virtually all of the consciousness mavens assume without much examination, and that is that Descartes was wrong and that dualism is bad. Dismissing Descartes is the most common opening move of nearly everyone in consciousness studies today, including both Dennett and Searle, but before we join them it would be a good idea to see where that dismissal takes them. Deprecations of Descartes almost always function as a means toward collapsing any useful distinction between spiritual and material substance and establishing some form of materialism, and that is a dangerous goal for Christians to applaud.

Books Discussed in this Essay

Patricia S. Churchland and Terence J. Sejnowski, The Computational Brain
(MIT Press, 1992), 544 pp.; $47.50,
hardcover; $19.95, paper.

Francis Crick, The Astonishing Hypothesis: The Scientific Search for the Soul
(Scribners, 1994), 317 pp.; $25.

Daniel Dennett, Consciousness Explained
(Little Brown, 1991), 511 pp.; $27.95.

Fred J. Dretske, Naturalizing the Mind
(MIT Press, 1995), 208 pp.; $22.50, hardcover; $12.50, paper.

Gerald M. Edelman, Bright Air, Brilliant Fire: On the Matter of the Mind
(Basic Books, 1989), 384 pp.; $35.

Roger Penrose, Shadows of the Mind: A Search for the Missing Science of Consciousness
(Oxford University Press, 1994), 457 pp.; $25, hardcover; $16.95, paper.

Israel Rosenfield, The Strange, Familiar, and Forgotten: An Anatomy of Consciousness
(Alfred A. Knopf, 1992), 157 pp.; $20.

John R. Searle, The Rediscovery of the Mind
(MIT Press, 1992), 270 pp.; $30, hardcover; $14, paper.

I would like to ask, if it's not too impertinent, just why Descartes, or at least mind-body dualism, should be so unspeakable. For one thing, it tends to come naturally, and that response should not be dismissed out of hand. As John Foster argues in The Immaterial Self: A Defence of the Cartesian Dualist Conception of the Mind (1991), "Our ordinary intuition is that, despite its attachment to an embodied subject, and despite its intimate causal dependence on the relevant neural processes, mentality cannot be reduced to non-mental factors." Searle, in fact, concedes that "the man-in-the-street is a Cartesian," and he likes to tell the story of going to hear a lecture by the Dalai Lama some years ago, only to find himself treated from that very unlikely source to a hearty discourse on mind-body dualism.

Dualism, admittedly, has its weaknesses. It can slide into skepticism about the reality of the external world; it lacks a good description of what guarantees that mind and body can interact; and it even creates difficulties in describing sleep. In Christian hands, dualism has often been pushed into various forms of Platonism, epiphenomenalism, and finally into the occasionalism so beloved of Nicholas Malebranche and Jonathan Edwards. But at least, as Foster points out, "the dualist gives a radically non-physicalist account of what exists or occurs within the mind: he takes sensations, thought-episodes, decisions, instances of belief, and so on, to be wholly non-physical—to be devoid of any intrinsic physical attributes or location in physical space." That is not a bad way of accounting for the soul; and, for that matter, Malebranche and Edwards are not bad theological company.

One thing is certain, though. As Dennett writes, "This is a glorious time to be involved in research on the mind." At this moment, he rejoices, "the frontier of research on the mind is so wide open that there is almost no settled wisdom about what the right questions and methods are." It will be strange, considering what is at stake, if Christians seize no part of this glorious time for their own. "Now is the time to take the problem of consciousness seriously," Francis Crick declares, and I could not agree more. What, after all, does it profit a man to gain the whole world, and forfeit his soul?

Allen C. Guelzo is Grace F. Kea Professor of American History at Eastern College.

Copyright © 1997 by the author or Christianity Today/Books & Culture Magazine. For reprint information call 630-260-6200 or e-mail bceditor@BooksAndCulture.com.