Macroscopic Ontology in Everettian Quantum Mechanics

Simon Saunders and David Wallace have proposed an appealing candidate semantics for interpreting linguistic communities embedded in an Everettian multiverse. It provides a charitable interpretation of our ordinary talk about the future, and allows us to retain a principle of bivalence for propositions and to retain the Law of Excluded Middle in the logic of propositions about the future. But difficulties arise when it comes to providing an appropriate account of the metaphysics of macroscopic objects and events. In this paper, I evaluate various metaphysical frameworks which might be combined with the SaundersWallace semantics. I conclude that the most appropriate metaphysics to underwrite the semantics renders Everettian quantum mechanics a theory of non-overlapping worlds.