This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
In 1994 I sat in an auditorium in Tucson, Arizona, as a young man with long brown hair began talking about consciousness. I remember being dimly conscious at first, perhaps because I was hung over, but gradually the sounds he was making woke me up. “There is nothing that we know more intimately than conscious experience,” he said, “but there is nothing that is harder to explain.”
Explaining what he meant by conscious experience, the long-haired man said: “When we see, for example, we experience visual sensations: the felt quality of redness, the experience of dark and light, the quality of depth in a visual field. Other experiences go along with perception in different modalities: the sound of a clarinet, the smell of mothballs. Then there are bodily sensations, from pains to orgasms; mental images that are conjured up internally; the felt quality of emotion, and the experience of a stream of conscious thought.”*
Consciousness is harder than other problems posed by the mind, the long-haired man argued, such as vision and memory. We have inklings how the brain accomplishes these functions, and we can build machines that replicate them, but we have no idea how the brain generates subjective experiences, or how to give them to machines.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
That long-haired young man was David Chalmers, speaking at a scientific conference on consciousness that I was covering for Scientific American. In part because of that lecture, Chalmers went on to become a leading philosopher, and many scientists and philosophers now refer to consciousness as “the hard problem.” It has become a pop-culture meme.
Last Saturday once again I sat in an audience listening to someone, a young woman this time, with short blond hair, talk passionately about the inadequacies of materialism for explaining consciousness--and particularly our awareness of beauty, of the sublime.
“Materialism is in trouble,” she said, “and we’re all materialists now. Everything is matter… What is to be done with the sublime if you’re proud to be a materialist? To save the appearance of value, no theory is too unlikely, no idea too far-out to float so long as it sounds like science—elementary particles with teeny-weeny consciousness; or a cosmos with attitude; or the life of the mind as the software of a biological computer. These are desperate measures…! What does materialism remind you of? It’s a faith.”
The speech was delivered by a real person, an actress, playing an imaginary person, a psychologist named Hilary, in a play called The Hard Problem. Hilary is the play’s central character, although the hard problem itself is arguably the central character. Actually, The Mind-Body Problem would be a more accurate title for the play, because it’s not just about consciousness. It’s about all the big mind-related puzzles: morality, free will, love, beauty, the meaning of life. The characters include scientists trying to crack the mind-body problem and the “squillionaire” financier who funds them.
Playwright Tom Stoppard, renowned for plays with philosophical themes, explores how material processes could generate consciousness and other deep features of the human condition. How does matter make minds, and how does is yield ought? Does physics plus Darwin and the double helix tell us all we need to know? Stoppard’s characters squabble over these questions while lusting, scheming, loving, pitying, regretting, suffering, feeling. We sense the strange loopiness of conscious creatures agonizing over consciousness.
Tormented by something she did in her teens, Hilary doesn’t think the psyche, with its intuitions of good and evil, can be reduced to neurons and genes. She prays for God’s forgiveness, even though she’s not sure He exists. Hilary’s occasional lover Spike (a term for neural signal) is a neuropsychologist and hard-core materialist, who thinks altruism, kindness, is just another manifestation of our innate selfishness.
When Spike catches Hilary praying, he mocks her. Science, he says, has “taken you to bits and put you back together from the atoms upward so you understand how you work and how everything around you works. We’ve accounted for every particle in the universe except for dark matter, and we’re working on that. And here you are on your knees to what? To who? You might as well pray to Peter Rabbit.”
“Explain consciousness,” Hilary retorts. Spike, it turns out, thinks even simple, non-biological information-processing systems might be conscious. Now it is Hilary’s turn to mock. “You believe a thermostat has consciousness potential,” she says, “but you find God a bit of a stretch?”
Stoppard and Chalmers raise the same question: Can science solve the mind-body problem, the deepest mystery of existence? The philosopher thinks so. In 1994 he said that “there is no reason to believe that [the hard problem] will remain permanently unsolved.” He thought a solution required moving beyond conventional materialistic methods, in which a phenomenon is reduced to physical processes.
He proposed that reality, in addition to matter and energy, consists of information. Information has an objective, physical aspect, which can be measured, and a subjective aspect, which manifests itself as conscious states. Consciousness is a property of anything that processes information--like a thermostat. Chalmers actually used this example, which Hilary derides.
When I interviewed Chalmers last year, he remained hopeful, sort of, that scientists, with philosophers’ help, can solve the hard problem. “I’d be happy if we got to the point where, say, in 50 or 100 years we at least have some candidate theories, serious, well-developed mathematical theories that are consistent with the data,” he said. “But we’re not even close to that point yet.”
I can’t be sure what Tom Stoppard thinks, but I suspect Hilary speaks for him. She definitely speaks for me. I don't believe in a God who answers prayers. But I grinned and nodded when Hilary said that “every theory proposed for the problem of consciousness has the same degree of demonstrability as divine intervention.”
As I argue in my new book Mind-Body Problems, I don’t think we can solve the hard problem in the same way we have solved, say, photosynthesis or heredity. (Yes, we still have details to work out when it comes to heredity, but the framework is in place.) Information-based theories of consciousness won’t work, for reasons that I spell out here. I believe and, yes, hope that the more we learn about ourselves, the more we will see ourselves as infinitely, inexplicably improbable--even, you might say, miraculous.
What worries me is that we might think we have solved the hard problem and stop marveling at ourselves. In fact, some philosophers, notably Daniel Dennett, have tried to explain away the hard problem by claiming that consciousness isn’t that big a deal. In a sense, consciousness doesn’t even exist, Dennett argues, because it is an “illusion” produced by our brains.
For rebuttals of this position, see critiques by philosopher Galen Strawson and by me. Or see Stoppard’s marvelous play. Like all great artists, Stoppard doesn’t pretend to solve the mind-body problem. He does something much more valuable. He dramatizes the problem, upholds it, turns it this way and that way, so we can see it from different and even contrary perspectives, and rediscover ourselves in all our sublime weirdness.
*I am quoting from Chalmers’s paper “Facing up to the Problem of Consciousness,” which is based on his Tucson lecture and can be found here.
Further Reading:
Mind-Body Problems (free online edition)
Mind-Body Problems (abridged Kindle edition)
Mind–Body Problems: My Meta-Solution to the Mystery of Who We Really Are
Why the Mind–Body Problem Can't Have a Single, Objective Solution
Jellyfish, Sexbots and the Solipsism Problem
The Mind–Body Problem, Scientific Regress and "Woo"
Can Integrated Information Theory Explain Consciousness?