Carl Hempel

Carl Gustav Hempel was born on 8 January 1905 in Oranienburg, in the German Empire, and died on 9 November 1997 at a nursing home near Princeton, New Jersey. He studied under Hans Reichenbach at the Universities of Gottingen, Heidelberg and Berlin, then left Germany for Belgium in 1935 because of Nazi antisemitic policy and his wife's Jewish ancestry, emigrating to the United States in 1937 and becoming a naturalized citizen. He taught at the City College of New York from 1939 to 1948, at Yale University from 1948 to 1955, then for many years at Princeton University, made emeritus there in 1973, followed by periods at the Hebrew University of Jerusalem and, from 1977 to 1985, the University of Pittsburgh. With Paul Oppenheim he set out the deductive-nomological model of scientific explanation in a widely read 1948 paper, holding that explaining an event means showing it follows logically from general laws together with the relevant initial conditions, and he distinguished this from inductive-statistical explanation, where the laws involved are only probabilistic. He is also known for the raven paradox, his observation that, taken at face value, the statement all ravens are black is logically confirmed by the sighting of any non black, non raven object, such as a white shoe, a result that exposed unexpected difficulties in the logic of scientific confirmation.