Biologist Jerry Coyne responds to a recent post by Vincent Torley on the topic of whether the brain is a kind of computer. Torley had cited me in defense of the claim that the intentionality or “meaningfulness” of our thoughts cannot be explained in materialist terms. Coyne responds as follows:
I’ll leave this one to the philosophers, except to say that “meaning” seem [sic] to pose no problem, either physically or evolutionarily, to me: our brain-modules have evolved to make sense of what we take in from the environment.
The fallacy Coyne commits here should be cringe-makingly obvious to anyone who’s taken a philosophy of mind course. Coyne “explains” intentionality by telling us that “brain-modules” have evolved to “make sense” of our environment. But to “make sense” of something is, of course, to apply concepts to it, to affirm certain propositions about it, and so forth. In other words, the capacity to “make sense” of something itself presupposes meaning or intentionality. Hence, if what Coyne means to say is that an individual “brain-module” operating at the subpersonal level “makes sense” of some aspect of the environment, then his position is just a textbook instance of the homunculus fallacy: It amounts to the claim that we have intentionality because our parts have intentionality, which merely relocates the problem rather than solving it. If instead what Coyne means is that the collection of “brain-modules” operating together constitute a mind which “makes sense” of the environment, then he has put forward a tautology – the brain manifests intentionality by virtue of “making sense” of the world, where to “make sense” is to manifest intentionality. Either way, he has explained nothing.