Hempel and the Problem of Provisos

Abstract Carl G. Hempel retired from Princeton in 1973. In 1977 he became University Professor of Philosophy at the University of Pittsburgh.1 Around that time he widely read papers in which he argued that deductive-nomological explanations were not logically valid deductions because they involved unstated ceteris paribus conditions, or as he called them, “provisos.” Many of us who heard these presentations marveled how in his later years Hempel was systematically calling into question his earlier work on explanation, theories, and the like. We took it as a mark of an intellectual integrity Hempel shared with Carnap where getting things right was paramount.