This book addresses a tightly knit cluster of questions in the philosophy of mind. There is the question: Are mental properties identical with physical properties? An affirmative answer would seem to secure the truth of physicalism regarding the mind, i.e., the belief that all mental phenomena obtain solely in virtue of physical phenomena. If the answer is negative, then the question arises: Can this solely in virtue of relation be understood as some kind of dependence short of identity? And answering this requires answering two further questions. Exactly what sort of...