 In other words, there are two conceptions of identity: On one the general identity relation is pieced together from the different identity relations for different categories of things. For a and b to be identical is for them to be the same person or the same number or the same artifact or …. On the other conception, there is a general notion of identity, perhaps given by the identity laws discussed in  Section 3.2,  and the specific ones are ways of instantiating that relation. The best argument for the first view is that the pieces seem too diverse to be parts of the same general relation. The best argument for the second is that as we move from domain to domain, and even invent new ones, the general identity scheme guides our development of an understanding of the more local notion. For a detailed analysis of Wiggins’ claims see Snowdon 2009.