Weak Reference or the True Semantics of ‘Relative Identity Statements’

Suppose a certain lump of clay is modelled into a distinctly round statue at one point in time and then remodelled into another, distinctively angular statue at another point in time. Looking at two photographs of the two statues, the following sentence seems both acceptable and true: (1) This is the same lump of clay but not the same statue as that. (1) is a statement that appears to describe relations of relative identity, identity that is relative to a sortal concept. It is a statement that apparently involves two referential terms, this and that, and says that the referent of the one term is identical to the referent of the other term relative to the sortal concept ‘lump of clay’, but not relative to the sortal concept ‘statue’. Identity statements such as (1) thus seem to support Geach’s (1962, 1972) rather controversial metaphysical view that the identity of objects is sortal-relative, rather than absolute. Sentences like (1), though not much discussed as such in the literature, appear to be the only sort of truly natural, acceptable kind of sentence in English describing (apparently) cases of relative identity. In this paper, I will argue that the view that (1) involves a notion of relative identity i