The deepest of all scientific mysteries, I once thought, is why there’s something rather than nothing. Now I think mind is the deepest mystery, because without mind, there might as well be nothing.

I recently posted a four-part report on “The Science of Consciousness,” a conference in Tucson, Arizona, where hundreds of scientists and philosophers pondered the mind-body problem. As I mentioned in one of my dispatches, I gave a talk at the conference. Since I described it only sketchily, I’m presenting my major points here. First, my title and abstract:

“THE QUEST TO SOLVE CONSCIOUSNESS: A SKEPTIC’S VIEW.” In 1994, I reported on the first Tucson “Science of Consciousness” meeting for Scientific American in an article titled “Can Science Explain Consciousness?” Ever since, I have continued to track research into how matter makes minds--or, more specifically, how physical objects generate subjective mental states. This is what philosopher David Chalmers, at that 1994 conference, described as “the hard problem” of consciousness. In this talk, I’ll assess major ongoing approaches to consciousness. Do they represent genuine progress, or do they corroborate the mysterian position that the hard problem is intractable?

I was deliberately vague, because I wanted my talk to be approved by conference organizer Stuart Hameroff. When I gave the talk, I changed the title to “Scientific Regress and the Mind-Body Problem” for two reasons. One, I like the old-fashioned philosopher’s phrase “mind-body problem,” which is about how matter makes mind. Two, I could express more bluntly my thesis, which is that research into the mind-body problem is regressing.

Below are points I made (or tried to make, I managed my time poorly) in my talk:


Philosophers disagree on who first posed the mind-body problem. Descartes often gets credit, but my vote goes to Socrates (as described by Plato in Phaedo). While sitting in an Athenian prison awaiting his execution, Socrates ridiculed the notion that his plight could be explained in physical terms, such as “the contraction or relaxation of the muscles.” He was in prison because the “Athenians have thought fit to condemn me, and I have thought it right to undergo my sentence.” Socrates was recognizing the gap between physiological and psychological causation. That’s the mind-body problem.


After Socrates, there followed more than two millennia of what I unfairly call “pointless philosophical bickering.” Thinkers trying to solve the mind-body problem generally fell into one of three camps: Idealism (mind rules), materialism (matter rules) and dualism (matter and mind are separate but equal).


In the early 1990s the great Francis Crick and a smart young sidekick, Christof Koch, said it was time to rescue the mind-body problem from philosophers and make it a respectable scientific problem. They proposed that science could “solve” consciousness by finding its “neural correlates,” that is, processes in the brain that correspond to conscious states. They even suggested a possible candidate for a neural correlate: 40-hertz oscillations, the simultaneous firing of many neurons 40 times a second.


Crick spelled out his hard-core materialist credo almost too clearly in his 1994 book The Astonishing Hypothesis. He declared that “you,’ your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are no more than the behavior of a vast assembly of neurons… you’re nothing but a pack of neurons.” I once told Crick that The Depressing Hypothesis would have been a more accurate title for his book. He chuckled.


Two other big-shot scientists were claiming to have solved the mind-body problem in the early 1990s. One was Gerald Edelman, who proposed in Bright Air, Brilliant Fire (1992) and other books that consciousness results from competition between populations of neurons responding to stimuli.

Critics complained that Edelman’s theory, which he called “neural Darwinism,” was just an obscure, pretentious version of neural-network theory. Crick said “neural Edelmanism” would have been a more accurate name for the theory, and he did not mean that as a compliment. Neurologist/author Oliver Sacks is the only brain scientist of note who really liked Edelman’s theory.


Physicist Roger Penrose spelled out a more radical view in The Emperor’s New Mind (1989) and later books. Based on his interpretation of Godel’s theorem and introspection into his own brilliant mind, Penrose argued that consciousness must be based on non-deterministic quantum effects. He teamed up with anesthesiologist Stuart Hameroff and the pair produced ever-more-elaborate quantum-consciousness theories.


All the above approaches to the mind-body problem and many more were represented at “Toward a Science of Consciousness,” the first of many biennial conferences in Tucson. Koch gave a talk on neural correlates. Penrose, Hameroff and others touted quantum consciousness. Other speakers presented chaotic or holographic models. Some emphasized the importance of mystical and paranormal phenomena. It was lots of fun, but the proportion of flakey ideas, or “woo,” to serious suppositions was high. (“Woo” can be used as an adjective or noun. Variant: “woowoo.”) The field was obviously pre-scientific, still in search of its unifying paradigm, although the neural-correlates approach of Crick and Koch seemed promising.


The young Australian philosopher Chalmers generated lots of chatter at Tucson when he said that consciousness—subjective experience-- is different from other natural phenomena and hence unlikely to be solved with conventional, materialistic approaches. The "hard problem” of consciousness, Chalmers said, might be solved by assuming that information—along with matter and energy—is a fundamental property of reality. Chalmers seemed to be reviving not only dualism but also panpsychism, the ancient mystical doctrine that everything is at least a little bit conscious.


I liked Chalmers’s discussion of how “hard” consciousness is, but I found his information conjecture too hand-wavy. Woo. And panpsychism? Come on. So I was delighted when Koch confronted Chalmers at a reception in Tucson and criticized his ideas as untestable. “Why don’t you just say the Holy Ghost comes down into your brain and makes you conscious?” Koch asked. Koch, who also criticized quantum-consciousness theories, was standing up for common sense and against woo. Or so I implied in my write-up of the 1994 Tucson conference for Scientific American.


I kept reporting on the mind-body problem over the next two decades. For a while, I got excited about the “neural code,” the rules or algorithms that transform the firing of brain cells and other neural activity into perceptions, thoughts, memories, emotions. Koch, my neuroscience go-to guy, warned that there might be many neural codes, operating at different scales in the brain, and our brains might even invent new codes in response to different experiences. The neural code, if it exists, will certainly be much more complex and difficult to crack than the genetic code.


About a decade ago Guilio Tononi, a former student of Edelman, proposed an ambitious theory of consciousness, integrated information theory. According to IIT, any physical system, not just a brain, is conscious if it passes a certain threshold of complexity, defined by the term phi. After attending a two-day conference on IIT at New York University, I concluded that IIT is highly implausible, for reasons that I go through here. IIT is essentially an elaborate, mathematical version of the old information-based idea that Chalmers presented in Tucson in 1994. And like the Chalmers conjecture, IIT implies than panpsychism is true.


That brings me to arguably the most significant development of the last two decades of research on the mind-body problem: Koch, who in 1994 resisted the old Chalmers information conjecture, has embraced integrated information theory and its corollary, panpsychism. Koch has suggested that even a proton might possess a smidgeon of proto-consciousness. I equate the promotion of panpsychism by Koch, Tononi, Chalmers and other prominent mind-theorists to the promotion of multiverse theories by leading physicists. These are signs of desperation, not progress.

There’s another reason I don’t like IIT. From a cosmic perspective, the mind-body problem asks how a strictly physical universe gave rise to consciousness. According to IIT/panpsychism, consciousness was there from the start, glimmering in the big bang. That’s not an answer, that’s cheating. It’s like explaining how life began by saying the big bang was a little bit alive.


Returning to Tucson after 22 years bolstered my sense that mind-body research, far from advancing, is regressing. There was more diversity of speculation, and woo, than in 1994. Hameroff and others presented quantum theories of consciousness, even though few mainstream neuroscientists take them seriously. (Koch is still opposed to quantum woo. He emailed me that it is “very unlikely that [quantum] effects play a major role in cognition, including consciousness.") The conference also featured talks on “Bayesian brain” models of cognition, integrated information theory, panpsychism, paranormal phenomena and more, much more. Diversity of speculation is a sign not of vitality but of weakness. It means researchers haven’t found an approach strong enough to compel consensus and convergence.


Some philosophers, notably Colin McGinn, argue that the mind-body problem is unsolvable. Just as rats aren’t smart enough to do arithmetic, McGinn suggests, we’re not smart enough to figure out consciousness. Philosopher Owen Flanagan calls proponents of this pessimistic position “mysterians.”

Mysterianism seems increasingly reasonable to me. I doubt science will ever give us a theory so potent that we think, “Ah, so that explains consciousness.” But unlike McGinn, I don’t think we’re too dumb to solve the mind-body problem. In fact, I suspect that the smarter we get, the more puzzled we will be by our own minds.

Mysterianism is more common than you might guess. Quantum-computation theorist Scott Aaronson recently said on this blog: “I should confess to extreme skepticism that there can even exist a ‘solution’ to the mind-body problem.”

Even Chalmers warns that the quest to solve the mind-body problem will probably be a long, hard slog. “I’d be happy if we got to the point where say in 50 or 100 years time we at least have some candidate theories,” he told me recently.

Koch acknowledges that IIT might not pan out, but he vehemently rejects mysterianism, arguing that that it could foment “defeatism” and hence become a self-fulfilling prophecy. “It’s very fraught with danger to claim that we will never understand,” Koch told me recently.

I agree, and I admire Koch for his can-do spirit (which is shared, let me emphasize, by Aaronson and Chalmers and every other mind-theorist I know). Maybe we will never solve the mind-body problem, but we must never stop trying. Who knows? Maybe IIT will pan out, or we’ll crack the neural code. And even if we don’t explain consciousness, our investigations will surely yield lots of practical applications, such as neural prosthetics and bionic upgrades.

But that raises another question. What if science boosts our minds’ power without giving us greater self-understanding? Shouldn’t that be cause for concern?

Further Reading:

Meta-post: Horgan Posts on Brain and Mind Science

Dispatch from the Desert of Consciousness Research, Part 1

Dispatch from the Desert of Consciousness Research, Part 2

Dispatch from the Desert of Consciousness Research, Part 3

Dispatch from the Desert of Consciousness Research, Part 4

Flashback: My Report on First Consciousness Powwow in Tucson. How Far Has Science Come Since Then?

Can Integrated Information Theory Explain Consciousness?

Are Brains Bayesian?

The Singularity and the Neural Code

Why information can't be the basis of reality

Is Scientific Materialism "Almost Certainly False"?

Scott Aaronson Answers Every Ridiculously Big Question I Throw at Him

Christof Koch on Free Will, the Singularity and the Quest to Crack Consciousness

Skeptic Debunks Spoon-Bending and Fosters World Peace