Paul Lorenzen

Paul Lorenzen, who lived from 24 March 1915 to 1 October 1994, was a German philosopher and mathematician. He founded the Erlangen School of constructivism with Wilhelm Kamlah and, with Kuno Lorenz, invented game semantics. He earned his doctorate at the University of Gottingen in 1938 under Helmut Hasse, became an assistant to Wolfgang Krull at the University of Bonn in 1939, and stayed there until 1949. His main mathematical work lay in the foundations of mathematics and proof theory, where he created and modified constructive mathematics, and he developed constructive logic, constructive type theory and a predicative constructive analysis in the manner of Hermann Weyl. He moved to the University of Erlangen in 1962, taught in the United States at Stanford, Texas and Boston, and was John Locke Lecturer in 1967 and 1968, when he proposed normative logic as a basis for ethics. With Wilhelm Kamlah he wrote Logical Propaedeutic, and with Peter Janich he worked out a protophysics of time and space.