Abstract

Possible worlds semantics (PWS) is a family of methods that have been used to analyze a wide variety of intensional phenomena, including modality, conditionals, tense and temporal adverbs, obligation, and reports of informational and cognitive content. PWS spurred the development of philosophical logic and led to new applications of logic in computer science and artificial intelligence. It revolutionized the study of the semantics of natural languages. PWS has inspired analyses of many concepts of philosophical importance, and the concept of a possible world has been at the heart of important philosophical systems. (See also POSSIBLE WORLDS, PHILOSOPHICAL ISSUES IN..