Why Sense Cannot Be Made of Vague Identity1

Abstract

In this paper I present a new argument against vague identity | one that is more fundamental than existing arguments | and I also try to explain why we nd the idea of vague identity puzzling, in a way that will dispel the puzzlement. In brief, my argument is this: to make clear sense of something, one must at least model it set-theoretically; but due to the special place of identity in set-theoretic models, any vague relation that one does model set-theoretically will not be identity, for real identity will already be there, built into the background of the model, and perfectly precise.