Abstract

Sameness and Substance Renewed (hereafter, 2001) is, in effect, a second edition of Wiggins’s 1980 book Sameness and Substance (hereafter, 1980), which in turn expanded and corrected some ideas in his 1967 Identity and Spatio-Temporal Continuity (hereafter, 1967). All three books have similar aims. The first is to argue, primarily against Geach, that identity is absolute not relative. The second is to argue that, despite this, whenever an identity claim a = b is true, there is a sortal f such that a is the same f as b. The biggest difference between 1967 and the two later books is that the later books contain much more detail on what a sortal must be if this claim, called D, is to be both correct and philosophically interesting. The third aim is to apply the first two conclusions to the topic of personal identity.