An interesting moment in class today, where some of us were thinking about whether eliminative materialism—which seeks to reduce thinking to the outpourings of neuronal activity—is in a kind of denial.
Everywhere we see brains, we may well see thinking happening. But we don't see thinking where there aren't brains. So sure, thinking emerges from things like brains.
But thinking isn't reducible to the brain. Otherwise the truth value of "Thinking is reducible to the brain" (or any statement whatsoever) would also be reducible to the brain. So there would be an infinite regress. It is better to think of thinking as an autonomous pattern, indeed one that can exert downward causality on the system out of which it emerges.
What eliminative materialism seeks to cover up in this assertion is precisely the transcendental gap between thought and the physical entity whose activity emerges as thought.
Because of this gap, the human is assailed by a kind of pincer movement, with one claw of the pincer coming from the world of "matter," the other coming from the world of "thought." Both entities are nonhuman.
The eliminationist seeks to preserve the dominance and centrality of the human in the form of her or his thinking. Eliminative science claims special access to reality, and claims to make true statements about reality, a claim that we see is involved in an infinite regress. In a sense, we could argue that eliminative materialism is nowhere near eliminative enough.