Modal Realism and the Possibility of Island Universes: Why There are no Possible Worlds

Abstract

Abstract In this article, I defend Lewisian modal realism against objections arising from the possibility of ‘Island Universes’ and other similar cases. The problem comes from Lewis’ claim that possible worlds are spatio-temporally isolated. I suggest a modification of Lewisian modal realism in order to avoid this family of objections. This modification may sound quite radical since it amounts to abandoning the very notion of a possible world, but as radical as it may sound it in fact remains well in the spirit of Lewis’ original view.