In this book, Derk Pereboom explores how physicalism might best be formulated and defended against the best anti-physicalist arguments. Two responses to the knowledge and conceivability arguments are set out and developed. The first exploits the open possibility that introspective representations fail to represent mental properties as they are in themselves; specifically, that introspection represents phenomenal properties as having certain characteristic qualitative natures, which these properties might actually lack. The second response draws on the proposal that currently unknown...