LET’S SAY YOU WERE GOD. How could you know this? How could you be sure that you weren’t rather a mad person, thinking you were God? You’d be omniscient of course, so you would know that you were God. But only if you were God. Otherwise you would only think that you were omniscient.
You might be reassured that you really were God if you could solve what’s come to be called the “hard problem of consciousness.” At the heart of Western theology is the idea that God is capable of creating, and has created, individual subjectivity, individual selves and souls, each of them a consciousness. So, if you were God, you would understand how to create these separate, individual consciousnesses. Indeed, you could test yourself by snapping your divine fingers and creating one on the spot. It might look back at you with yellow, watery, but speculative eyes (as the monster looked at Frankenstein). But would it actually see you? Would it be conscious? How could you tell, even if you were God? You might think of merging your consciousness with its consciousness perhaps, so as to see from its point of view. But all you’d be conscious of is your own consciousness, which would be using its body as a perceptual instrument.
To put the question simply, if God exists, how could “He” know that we existed? How could He know that we weren’t merely animated matter, zombies, or biological machines, like the pedagogical mannequin, a Turing machine affectlessly oppressing the seekers after truth in the dream world of Giulio Tononi’s Phi: A Voyage from the Brain to the Soul? How could God know that we were living souls, and not just perfect simulations?
This is a question for speculative fiction. Think of Rheya, the twice-created, twice-lost human companion that the inscrutable planet Solaris, in Stanislaw Lem’s eponymous novel, offers, in all her need and vulnerability and love, to the scientist Kelvin who has come to study its composition. Or consider William Gibson’s Dixie Flatline (in his novel Neuromancer), an artificial software construct who doesn’t know whether he’s sentient but says that he feels as though he is. Are they real? Even they can’t tell us, and surely no one could be better placed to tell us than they.
Phi is also a work of speculative fiction, a kind of fantasy exposition of science that ends up turning into a record of scientific fantasy as it grapples with ever-deeper philosophical questions. At least since Aristotle, science and philosophy have been on uneasy terms. Philosophy takes it as its vocation to ask questions that transcend the answers that science can provide; but then the history of science is also the history of the answers to those seemingly intractable questions. Zeno, a Greek philosopher, seems to show that there is no point in space where Achilles can race past a moving tortoise with a head start; but Einstein establishes that there is no absolute space, and therefore no need to imagine such a point within it.
This doesn’t mean that philosophy is simply anti-science. Darwin lists Aristotle as one of the scientists who collected evidence for the kinds of changes evolution produces. Indeed, both a scientist and a philosopher, Aristotle had already refuted Zeno in ways that anticipated Einstein, since he, too, argued that movement was not irreducible to a simple relationship with a background. It’s not what Aristotle got wrong that matters, but what he got right, and he got a lot right because he was asking philosophical questions about how the world could be the way it was, questions that spurred science to its eventual answers.
Darwin, too, sought answers for deep philosophical questions, writing in his private notebook in September of 1838:
Plato says in Phaedo that our “necessary ideas” arise from the preexistence of the soul, are not derivable from experience. — read monkeys for preexistence.
Evolution solves a long-standing and hard philosophical problem: how do we know what we haven’t learned from experience? The answer is that our biological inheritance includes the golden nuggets of useful knowledge, that natural selection has panned them from the three-billion-year river of experience. Such nuggets seem to include many heterogeneous things like logical structure and rules of inference, and perhaps the grammar such logic implies: the impermeability of bodies, the ability to perceive depth by fusing two dimensional images, preferential recognition of tree-like objects, and a dislike for spiders.
Darwin’s solution not only explains where knowledge comes from but also modifies our sense of what knowledge is. Knowledge is a capacity to represent with reasonable adequacy the important elements of the world with which we must interact in the course of our lives if we are to achieve reproductive success. This is, essentially, a pragmatist view of knowledge, and the pragmatism of William James and John Dewey is avowedly Darwinian. The value of knowledge is its usefulness in negotiating with the world. Knowledge preexists us, not only in, but as, the part of the soul legated to us by our biological forbears. Our souls preexist us in monkeys (or in the primate ancestors we share with them).
If Darwin’s solution to Plato’s problem redefines what knowledge is, it also radically divorces the idea of personal identity or of the subjective self from the preexistent knowledge with which it is born. The preexistent soul in Darwin is biological structure (what’s “hardwired,” to use the standard metaphor), and not the individual consciousness who thinks these necessary ideas, or if you prefer, in whom these necessary ideas are thought. But what of that subjective soul, the consciousness that I have of myself as a conscious being, different and separate from anyone else?
Consciousness naturally seems to morph into the idea of personal identity (I am subjectively conscious only of and in myself, and therefore I think of myself as the possessor of my own consciousness), and we’re tempted to make the core of personal identity the way that it possesses what it possesses — i.e., consciousness. Consciousness is how we possess qualia: the redness of red, the bitterness of loss, the one-sided limit, or edge-of-the-phenomenal world experience of selfhood or personal identity itself (which Kant called the “transcendental unity of apperception”). Qualia are what consciousness possesses. Plato thought that we possessed such things before conception, and therefore we were conscious souls before we entered into our sublunary bodies. Darwin undoes that view: our necessary ideas are what we will think, but they are contained not in qualia but in germ form in our genetic structure, and only give rise to qualia after we come into our individual existences.
Some scientists, and some philosophers, think that the solution of the problem of consciousness lies here. Consciousness isn’t primary, as Plato seemed to think. It arises out of structure. To understand qualia, we need to understand structure first: of the brain and nervous system, and of the body it inhabits, and of the world that body inhabits. Giulio Tononi attempts to do just that in Phi, a book that revels in the richness of qualia, and that is gorgeously, though eccentrically, illustrated with doctored and cropped paintings and photographs, and densely populated with dream or hallucinatory versions of some of the greatest contributors to the philosophy and science and literature of consciousness and of thought. Figures like Leibniz, Kant, Darwin, Emily Dickinson (who is misquoted), William James, Borges, Kafka, Freud, Alan Turing, Claude Shannon, Francis Crick, Philip Larkin, and many others, all populate a Dantesque vision vouchsafed to Galileo.
Why does Tononi, a professor of psychiatry and expert in neuroscience (he is the David P. White Professor of Sleep Medicine and the Distinguished Chair in Consciousness Science at the University of Wisconsin), take Dante as his model? In part, he is tempted by the version of reality that exists most fully in the mind: in human consciousness. He follows his sometime collaborator, the Nobel Prize winning physiologist and theorist of neural Darwinism, Gerald Edelman, in trying to understand how it is that, in Emily Dickinson’s words, “The Brain — is wider than the Sky,” since all we know, all we can know, of the sky is what our brains can contain. This means that the brain is wider than the brain as well, since it is only in the brain that we can know anything about the brain. This Escherian structure — at the same time and in a symmetrical way — subordinates scientific thought to philosophical thought and philosophical thought to scientific thought; Tononi cites and dabbles in art and poetry to try to plumb this paradox. One way Tononi tries to have it both ways is to create a kind of small print, skeptical critic who appends explanations and assessments of the success or, more often, the failure of each chapter: this figure is rather like the voice in Wittgenstein, which his expositors always called “the interlocutor,” or like the internal and skeptical complainer that William Blake called “the Idiot Questioner.” The unimaginative complaints of this commentator seem to be a kind of blanket disclaimer meant to allow the wilder Tononi more leeway in fantasizing.
Phi begins with his faux-naïve, self-questioning, self-conscious assessment of what the book might be doing: “In his time, Galileo removed the observer from nature and opened the way for the objectivity of science. Perhaps this is why Galileo is engaged to return the observer to nature, to make subjectivity a part of science.” But of course the second Galileo, engaged here in “a journey in search of consciousness,” is a fictional character in Tononi’s book. Like Dante’s wayfarer, he meets many people in his dream vision and, as he learns familiar basics of neurology, we learn or relearn them with him. But he doesn’t seem headed to any Paradise. Unlike Oliver Sacks, who endorsed the idea that talk of neurological disease is a type of Arabian Nights entertainment, Tononi seems to get increasingly depressed rather than invigorated as he considers all the maladies the brain is heir to, and of all the ways that the mind can degenerate into fragments of consciousness, of will, of expressive capacity, of intelligence, insight, awareness, and information.
Tononi’s main point seems to be that consciousness is integrated information, which he calls Phi. The higher the Phi — in other words, the more “maximally irreducible” it is, and the more information is integrated into a complex, single-integrated entity that works as a whole — the more there exists of consciousness or awareness. This idea is meant to explain how we have qualia: not as a series of discrete atoms of awareness, like a pointillist painting (think Seurat) or Ben-Day dots (think Lichtenstein), but as their integration into a single experience. This integration somehow “condenses” into consciousness out of a mist of particular bits of information. What integrated information and consciousness have in common, and what seems to make Tononi think that the integration of information explains consciousness is the idea of irreducibility; according to the last pages of Tononi’s book, consciousness “is maximally irreducible.”
But the irreducibility of integrated information and the irreducibility of consciousness are not the same thing. For a scientist, Tononi is, to be sure, impressively interested in philosophical questions, but he doesn’t quite see the purport of some quite penetrating philosophical arguments. He’s a little too lazy (and a little too snarky), for example, when he reviews and shrugs off Kant‘s point about the elusive unity of apperception. Kant is less important here, though, than the contemporary philosopher Thomas Nagel, whom Tononi also cites without quite coming to grips with him. Nagel has been attacked for his recent book, Mind and Cosmos, which evinces skepticism for the totalizing, explanatory power of evolution, and indeed, Nagel opens himself up to legitimate criticism when he makes scientific claims that he has no business making (about the rate at which evolution could take place, for example). But if Nagel’s scientific objections are amateur, then his philosophical critique is powerful, a culminating synthesis of arguments he’s been making for over 40 years.
Tononi’s fictional Galileo meets Nagel in a purgatorial region of his dream, complete with a scared (and scary) bat; as Nagel famously argued in his seminal essay “What Is It Like to Be a Bat?” it is like something to be one. Tononi doesn’t think it much matters that we don’t know what it’s like to be a bat: bats have their qualia and we have ours. But he misses, or nearly misses, the force of Nagel’s critique. Nagel’s deepest question about consciousness is not provoked by the sheer fact of conscious experience. It’s the plurality of consciousness that’s strange. No objective scientific account of all the elements in the universe could say why I am me and you are you. Objectively speaking, we could accept that there are many different conscious beings. But we don’t have the ghost of an idea of how there could be an objective explanation for the distribution of subjectivities among them. Why is my consciousness mine? Why isn’t your consciousness mine? The hard question of consciousness is less this question, “How can consciousness exist?” than the question of how there can be more than one. What is the principle of discrimination between them?
Tononi, like a lot of other neurologically influenced scientists, from William James to Oliver Sacks, is fascinated by neural deficits and accidents that fracture consciousness into independent and plural consciousness. Most notoriously, people whose corpus callosum has been cut (often to control epilepsy), so that the two sides of their brains can no longer communicate with each other, thenceforth have two consciousnesses, each as separate from the other as “the breach from one mind to another,” which William James notably described as “perhaps the greatest breach in nature.” In such cases, it seems that either one consciousness can be turned into two, or that it’s a mistake to talk of a single consciousness. I think Tononi must be right to interpret this disturbing phenomenon by showing that consciousness doesn’t correspond to some Platonic soul. But that only makes consciousness, if possible, still more mysterious, still harder to imagine understanding, since once again we’re confronted not with a single phenomenon — consciousness itself — but the irreducible plurality of different consciousnesses.
Tononi offers a weak answer to this question: qualia belong to me if they’re sort of me-shaped. That seems right but woefully insufficient. It still doesn’t give us a way of understanding not that objects are different from each other but rather that subjects are. Nothing explains why I’m me, just as nothing could explain to the monster — not even his creator Frankenstein— why he is who he is, just as nothing could explain to God why God is God.
Unlike many of his neuroscientist colleagues, Tononi doesn’t really think he’s solved the problem of consciousness. He knows that his suggestions are jury-rigged. As his book progresses, he confronts the feebleness of science in the face of the phenomena it discovers. One reads this book with a kind of burgeoning terror at the complex vulnerabilities of the brain, the only place in the universe that the mind assuredly exists. Tononi seems just as grimly clear-sighted about this as any philosopher or poet. Science wants to know all, to be omniscient. But the study of the brain and its relation to consciousness seems to prove that even if scientists could play God (“the Brain is just the weight of God,” Dickinson concludes), even if they did achieve divine omniscience, they could never know how any other consciousnesses could exist, nor whether they did exist, nor how there could be a plurality of them. Gibson’s Dixie Flatline and Tononi’s Galileo don’t, in fact, have sentience. They’re fictional characters. How could any science, any omniscience, know that we were more real than they?
William Flesch teaches English, film, and some philosophy at Brandeis University. Among his books is Comeuppance: Costly Signaling, Altruistic Punishment, and Other Biological Components of Fiction (2008).