David Chalmers is one of the most prominent of the contemporary philosophers of mind and is noted for his rejection of the materialist view that all that's needed to understand what goes on when we think and experience sensation is better knowledge of how the brain works.
Chalmers holds that materialism does not, and cannot, explain the fundamental phenomena of consciousness. To explain that we need to posit the existence of something other than the matter that comprises our bodies and brains.
In this interview he explains that consciousness is not something that can be accounted for in terms of Darwinian evolution since there was no pressing need for it. We could have much more easily evolved to be like computer-driven robots or zombies - creatures able to perform all the tasks that humans perform but without having any awareness of our own selves and without experiencing sensations at all.
That consciousness somehow exists seems completely gratuitous and absolutely marvelous.
