Abstract

Following insights from the New Theory of Reference, it has become widely accepted that theoretical identities like ‘water = H2O' are necessary. However, some have challenged this claim. I propose yet another challenge in the form of a sceptical argument. The argument is based on the contention that the necessity of theoretical identities is dependent upon criteria of identity. Thus, a theoretical identity is necessary given one criterion of identity but contingent given another. Since we do not know which criteria of identity in fact obtain, it follows that, for all we know, theoretical identities may not be necessary