Abstract

Could Mark Antony have had all the properties of Julius Caesar and vice versa? This is a puzzle which was raised by N. L. Wilson, and I shall be concerned with it in Part I of this paper. The answer which we give to this puzzle has important implications for our notion of an identifiable individual. In Part II I examine some important consequences of accepting the coherence of a complete exchange of properties between two individuals—which we might call a “biography-swap.” I argue that one consequence is to establish the inadequacy of some views about reference advocated, for example, by Russell and A. N. Prior. This leads on to a more general problem of how it is that concrete particulars are grasped as objects of thought; and in resolving this problem, I argue in Part III that demonstratives play a crucial role in reference to particulars.