There are two archetypal reactions to the notion that we (you and I, these things that think and read and write) might be material (made of matter, explicable in principle by physics, not different in kind from toasters or computers). Even the notion itself can be described in two different ways, corresponding roughly to the two reactions to it: it is either the notion that we thinking things might be merely matter, or the notion that things that are merely matter might be able to think.

The two reactions are roughly "how wonderful, that matter might do all this", and "how terrible, that we might be merely that". As an avatar for the first, we have Richard Dawkins. As champions of the second, Roger Penrose and John Searle.

I am a Dawkinsian in this sense. I have been unable to read Penrose and Searle as other than irrational denial. Penrose says that by introspecting, he can tell that his consciousness is not merely doing calculation, and that therefore his consciousness cannot be anything that could arise from something accurately describable as calculation. Or something like that. He will not be unfashionable enough to say that we thinkers must partake of the divine, so he says that we must partake of something else fuzzy and transcendant; his suggestion is the quantum.

Searle similarly says that nothing but a brain could have the causal powers of the brain. There is something mysterious and necessarily biological about having intentional states. He has nothing in particular to back this up, except to maintain that anyone who thinks otherwise must be (famously) in the grip of an ideology. It is hard to maintain respect for someone who considers this a valid philosophical argument.