The Philosopher's Magazine recently passed along this quote from Thomas Huxley:
Indeed, and neuroscientists still marvel that something as astonishing as consciousness could be somehow generated by brute matter and could have evolved through purely mechanistic processes acting blindly and by chance.
How this could be so no one has as yet been able to say. Consciousness is a mystery, like life and gravity. It's hard enough to define it, it's devilishly difficult to understand it, and it seems impossible to explain it. How material substance can give rise to what philosophers refer to as the qualia of experience, sensation and awareness, is a bafflement.
Someday it might all be figured out, but we wonder whether it will ever be explicable in purely materialistic terms. We'll be greatly surprised if it is.