Philosophy Research Archives

Volume 8, 1982

Thomas R. Foster
Pages 169-183

Symmetrical Universes and the Identity of Indiscernibles

The view that numerical difference entails qualitative difference has come under attack from various quarters. One classical attack, advanced by Black, involves possible worlds which are symmetrical. In a symmetrical world, it is claimed, the identity of indiscernibles is false. I argue that such attacks are mistaken, basically because they confuse epistemological issues (such as, how to specify a quality difference) with ontological ones (such as, whether there is such a quality difference). In brief, though there may be some reasons for doubting the necessity of the Identity of lndiscernibles, the possibility of a symmetrical world is not one of them.