Worlds and Meaning

Abstract

This chapter discusses the possible world framework for intensional semantics, used for the semantics of ‘would’. It does not depend on any particular metaphysics of worlds, but the standard compositional clauses for the logical constants are a significant constraint. Semantic theories which invoke ‘impossible worlds’ flouting those constraints typically turn out to violate the principle of compositionality; since synonymy is not epistemically transparent to speakers, attempts to craft epistemically possible but metaphysically impossible worlds also tend to violate compositionality. Since worlds are best understood as objectively possible, in a broad sense, the proposed semantics makes counterfactuals with metaphysically impossible antecedents vacuously true; appearances to the contrary are an artefact of the suppositional heuristic (similar phenomena are noted for vacuous universal generalizations). This makes trouble for some prominent versions of fictionalist theories in metaphysics and various other philosophical theories which assume that counterpossibles vary in truth-value.