The Hard Problem of Consciousness poses a problem for philosophical materialism. The problem in a nutshell is that every function of consciousness can be achieved without consciousness—in zombies, for example. And this means that none of these functions is identical with consciousness. So how could consciousness be material? This is a problem.
Still, does the Hard Problem pose a problem for evolutionary biology as it stands today? Tom Nagel thinks so. His forthcoming book is entitled Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False. (It is available already on Kindle.) The Amazon blurb for the book reads like this:
The modern materialist approach to life has conspicuously failed to explain such central mind-related features of our world as consciousness, intentionality, meaning, and value. . . Since minds are features of biological systems that have developed through evolution, the standard materialist version of evolutionary biology is fundamentally incomplete. . . An adequate conception of nature would have to explain the appearance in the universe of materially irreducible conscious minds, as such.
Nagel’s recent review of a book by Alvin Plantinga in the New York Review of Books opens a window onto his line of thought. He writes:
when our faculties lead us to beliefs vastly removed from those our ancestors needed to survive—as in the recent production and assessment of evidence for the existence of the Higgs boson—Plantinga’s sceptical argument remains powerful.
This is rubbish. Plantinga is deeply committed to the idea that only things that are essential to the four Fs (feeding, fleeing, fighting, and making whoopee) can be produced by evolution. Since discovering the Higgs boson does not make a lot of whoopee, the faculty that is responsible can’t be evolved. Nagel seems to endorse this line of thought. But where exactly in neo-Darwinism do we find this principle: if it isn’t needed for survival, it isn’t evolved?
Start with sexual selection. Darwin proposed that non-adaptive traits (like the tail of the peacock) evolved by what today we call an “arms race.” The courting display of a large tail was sexually attractive to peahens. Thus a large tail was advantageous to peacocks: it got them mates, it got them descendants who benefited from the same sexual situation. Thus, peacocks evolved a huge tail. The tail was certainly not “needed to survive”—on the contrary.
Now I don’t want to say that the capacity to produce a Higgs boson is sexually selected. What I want to say is that a situation could have existed in which a little more rationality was advantageous as compared with a little bit less. This would lead to a spiral in which “intentionality, meaning, and value” was selected for, without being needed for survival. This is consistent with classic Darwinism. It’s similar to the “arms race” theory of peacock’s tails. What we need, to repeat, is this: if x is a little more intellectual than y, x is fitter than y. (Who knows why? But I can manufacture a scenario if needed.)
And what about consciousness? The thought is that for consciousness to be accommodated by “materialist neo-Darwinism” the “appearance of consciousness” has to be explained on evolutionary principles. Wrong! Let’s suppose that a certain kind of organism is conscious. Let’s concede the Hard Problem: we can’t reduce consciousness to any material property. But if this kind of organism happens to be conscious, and this was an advantage for it, and the basis for its consciousness is heritable . . . well then, this is all you need.
I would like to solve the evolution of consciousness in 700 words, but try as I have, I haven’t been able to. But I would like to ask: what is the problem exactly? Give me a hint. Well, I’ll just have to wait for the book.