Absolute Identity and Criteria of Identity

Abstract

With the results of the last chapter behind us we can now return to the investigation of Wiggins’ view that identity under a sortal concept entails indiscernibility, which, as we have seen, is based on his view that only an absolute equivalence relation, i.e. a four-term relation satisfying condition (1) of the last chapter, can serve as a criterion of identity suitable for association with a proper name. I shall argue that the notion of an absolute equivalence relation’s serving as a criterion of identity has no application,¹ and the argument will also make it obvious, I hope, that this is not because the idea of a criterion of identity has itself no application. Rather, we shall see how indispensable that notion is and what is its real significance.