The philosophical inquiry of Arthur Prior (1914-1969) has involved topics ranging from formal logics to ethics, while giving crucial contributions in modal logic, metaphysics, and the philosophy of time. Prior is considered the father of temporal logic and a forerunner of both current hybrid logic and Kripke's possible worlds semantics; also, he has supported a refined and go-ahead version of actualism, which is in turn grounded on a specific view on the relation between existence, facts and truth. Prior's approach to philosophy has been highly sensitive to the traditional questions in metaphysics and ontology, and at the same time has laid the grounds of new areas of research in modal logic. This entry aims at presenting and discussing some of Prior's most important contributions to philosophy and their relevance. In particular, the entry presents and discuss branching-time semantics and their application to the problem of determinism, hybrid logics and the reduction of instants to propositions, the modal logic Q and the problem of predication about contingently non-existing individuals.
EUT Edizioni Università di Trieste
Roberto Ciuni, Carlo Proietti, “Arthur Prior”, in "APhEx 10", 2014, pp. 39