Essays on indiscernibility

Abstract

This Thesis is a collection of essays on qualitatively indiscernible entities, i.e. entities which agree with respect to all the qualitative properties they instantiate. In Chapter 1 I introduce various accounts of indiscernibility, and provide a review of the relevant literature. Chapter 2 is dedicated to Leibniz’s principle of the Identity of Indiscernibles, the claim that indiscernibility suffices for numerical identity. I argue that if certain assumptions about identity criteria are accepted, the weakest non-trivial interpretation of the principle is one restricted solely to qualitative properties. In Chapter 3 I present a new counterexample to the Identity of Indiscernibles. In Chapter 4 I argue that Anti-Haecceitism, the claim that there are no maximal possibilities which differ only with respect to the non-qualitative possibilities they include, entails that the Identity of Indiscernibles holds of necessity. In Chapter 5 I propose a new account of qualitative properties, according to which a property is qualitative if and only if it is invariant under any identity assignment — where an identity assignment is a function from individuals and worlds to identities. In Chapter 6 I argue that singular reference to indiscernible individuals is possible, and show how current theories of Arbitrary Reference allow for a successful analysis of this phenomenon. In Chapter 7 I defend Arbitrary Reference against a popular objection, and advance a new probabilistic account of Arbitrary Reference. Finally, in Chapter 8, I show that singular reference to entities to which identity does not apply is impossible.

Date of Award	10 Jun 2024
Original language	English
Awarding Institution	University of St Andrews
Supervisor	Franz Berto (Supervisor)