The subject of this paper is the epistemology of identity: a general theory of knowledge, evidence and justification for the claim that one thing is identical to another. Although identity figures significantly in our epistemic lives, this is a topic that, to the best of my knowledge, has gone entirely unexplored. Initial attempts to integrate such an epistemology into existing theories of evidence---many of which are tailor-made for contingent propositions---are confounded by the necessity of identity. I defend a restricted form (...) of skepticism according to which the only knowable identity claims are trivial. (shrink)

This paper is about conceptual engineering. Specifically, it discusses a common objection to CE, which I call the Discontinuity Objection. According to the Discontinuity Objection, CE leads to problematic discontinuities in subject and/or inquiry – making it philosophically uninteresting or irrelevant. I argue that a conceptual engineer can dismiss the Discontinuity Objection by showing that the pre-engineering concept persists through the proposed changes. In other words, the Discontinuity Objection does not apply if the proposal involves identity-preserving changes. Two existing views (...) on identity-preserving changes are considered and rejected. I then argue that an identity-preserving conceptual change is one that allows the concept to continue to perform its function. A concept’s function is its job, its point and purpose, its role in a conceptual repertoire. In a slogan: Preserve a concept’s function, and you preserve the concept itself; preserve the concept, and you preserve the subject. The paper concludes by discussing some implications of this view. (shrink)

It is a philosophical commonplace that quantification involves, invokes, or presupposes, the relation of identity. There seem to be two major sources for this belief: the conviction that identity is implicated in the phenomenon of bound variable recurrence within the scope of a quantifier; memories of Quine’s insistence that quantification requires absolute identity for the values of variables. With respect to, I show that the only extant argument for a dependence of variable recurrence on identity, due to John Hawthorne, fails. (...) I further show that the function of variable recurrence is not subsumed under that of identity, so that a dependence of the former on the latter, if any, would have to be of a rather indirect nature. With respect to, I argue that the relevant passage in Quine fails to establish a connection between quantification and the identity relation, and indeed wasn’t intended by Quine to do so. (shrink)