The relationship of consciousness to brain, which Schopenhauer grandly referred to as the "world knot," remains an unsolved problem within both philosophy and science. The central focus in what follows is the relevance of science---from psychoanalysis to neurophysiology and quantum physics-to the mind-brain puzzle. Many would argue that we have advanced little since the age of the Greek philosophers, and that the extraordinary accumulation of neuroscientific knowledge in this century has helped not at all. Increas ingly, philosophers and scientists have tended to go their separate ways in...