Abstract

The fundamental purpose of this dissertation is to explore the conceptual mechanisms whereby we are enabled to talk of material objects. This is accomplished through examinations of the nature of, and the interrelations between, those concepts which figure in the characterization of our talk of objects, such as identity, sort, and individuation. I first examine the thesis of relative identity, and argue against it that identity should be construed as a two-place relation. The diagnosis of the mistake of the relative identity thesis reveals the quasi-semantic roles played by sortal concepts in individuation of objects. And it is shown that such a role of a sortal concept can be characterized by what I call the individuation function for that concept. I then proceed to consider the question how particular individuation functions come to be associated with sortal concepts. I argue that the conceptual operation formally equivalent to the principle of abstraction, which is often employed in introduction of certain sorts of abstract objects , provides a plausible means of characterizing individuation functions for various sorts of material objects. And some of the formal and substantial problems concerning formulation of specific abstraction principles for material sorts are investigated. Finally, I apply my account of individuation to a certain philosophical puzzle about fission of persisting objects. I argue that the puzzle arises from what I call failure of individuation, namely the fact that, in the case of fission, the relevant abstraction principle fails to determine an individuation function