David Chalmers is a leading thinker in contemporary philosophy of mind. He is Professor of Philosophy and Director of the Center for Consciousness at Australian National University. http://en.wikipedia.org/wiki/David_Chalmers Chalmers is known for being an avid critic of physicalism, believing that reductive approaches to the mind fail to appreciate the fundamental nature of consciousness. He is most widely known for sparking a revival of interest in property dualism, philosophical zombies, and for his formulation of the "Hard Problem of Consciousness." http://en.wikipedia.org/wiki/Emergence In this clip, Chalmers distinguishes between "strong" and "weak" emergence and explains the important differences between non-physical qualia and vitalism.