Universals, particulars, and the identity of indiscernables

This project is about the distinction between universals and particulars. The fundamental claim I defend is this: The distinction between universals and particulars can be vindicated via the fact that universals are identical if indiscernible while particulars are not identical if indiscernible. This way of "making" the universal-particular distinction is "extensionally" adequate--it (by and large) gets the pre-theoretical extensions of 'universal' and 'particular' right. The entities that one would ordinarily classify as universals get classified as universals, and the entities that one would ordinarily classify as particulars get classified as particulars. Furthermore, this way of making the distinction is "intensionally" adequate--it situates smoothly in the theory of universals and particulars motivated independently of the need to vindicate the distinction. The natures that universals and particulars must have if they are to play their respective theoretical roles require that universals are identical if indiscernible and that particulars are not. No more can reasonably be asked of a proposed universal-particular distinction.