Abstract

Actual facts abound and actual propositions are true because there is a world, the actual world, that the propositions correctly describe. Possibilities abound as well. The actual world reveals what there is, but it is far from clear that it also reveals what there might be. Philosophers have been aware of this limitation and have introduced the notion of a possible world. Finally, impossibilities abound because it turned out that possibilities do not exhaust the modal space as a whole. Beside the actual facts, and facts about the possible, there are facts about what is impossible. In order to explain this, philosophers have introduced the notion of an impossible world. This article is about impossible worlds. First, there is a presentation of the motivations for postulating impossible worlds as a tool for analysing impossible phenomena. This apparatus seems to deliver great advances in modal logic and semantics, but at the same time it gives rise to metaphysical issues concerning the nature of impossible worlds. Discourse about impossible worlds is explained in Sections 2 and 3. Section 4 provides an overview of the theories in discussion in the academic literature, and Section 5 summarises the drawbacks of those theories. Section 6 takes a closer look at the logical structure of impossible worlds, and Section 7 discusses the connection between impossible worlds and hyperintensionality.