Logical positivism incorporates the doctrines of the 'Vienna Circle,' a group of philosophers founded by the German philosopher Moritz Schlick (1882–1936) and which included Rudolf Carnap. At the heart of logical positivism was the assertion that apparently factual statements that were not sanctioned by logical or mathematical convention were meaningful only if they could conceivably be empirically verified. Thus only mathematics, logic, and science were deemed meaningful; ethics, metaphysics, and religion were considered worthless. The influence of logical positivism evaporated after World War II. See also positivism.