Nicholas Rescher (/ˈrɛʃər/; German: [ˈʀɛʃɐ]; born 1928) is a German-American philosopher at the University of Pittsburgh. He is the Chairman of the Center for Philosophy of Science and has formerly served as Chairman of the Philosophy Department. He has served as president for the American Catholic Philosophical Association, American G.W. Leibniz Society, American Metaphysical Society, American Philosophical Association, and C.S. Peirce Society.