This book is not written for posterity. It is meant to constitute part of my contribution to a continuing debate at the intersection of the philosophy of mind, the philosophy of language, epistemology, and the philosophy of cognitive science. The debate is over how mental states are individuated. Many philosophers, call them externalists (or anti individualists), believe that the individuation of mental states requires appeal to an individual's social and/ or physical environment. I am not among them; I am an internalist ( or individualist). This book attempts to show that the leading...