 Carl G. Hempel (1905–1997) was the principal proponent of the “covering law” theory of explanation and the paradoxes of confirmation as basic elements of the theory of science. A master of philosophical methodology, Hempel pursued explications of initially vague and ambiguous concepts, which were required to satisfy very specific criteria of adequacy. With Rudolf Carnap and Hans Reichenbach, he was instrumental in the transformation of the dominant philosophical movement of the 1930s and 40s, which was known as “logical positivism”, into the more nuanced position known as “logical empiricism”. His studies of induction, explanation, and rationality in science exerted a profound influence upon more than a generation of philosophers of science, many of whom became leaders of the discipline in their own right.