. 1872–1970. Born at Ravenscroft, Glos., he worked mainly in England (especially Cambridge), sometimes in America. His early fame rested on two main contributions to logic, the theory of DESCRIPTIONS and the theory of TYPES. He taught Wittgenstein at Cambridge before the First World War. His later work concentrated mainly on EPISTEMOLOGY, metaphysics and philosophy of mind, where he based himself mainly on the empiricist tradition of HUME, MILL, etc., though he was notorious for changing his views. He also stressed the importance to philosophy of modern scientific developments. A prolific writer, Russell was also famous for his great political and social commitment.
