Hugo Albert Emil Hermann Dingler (July 7, 1881, Munich – June 29, 1954, Munich) was a German scientist and philosopher. Life Hugo Dingler studied mathematics, philosophy, and physics with Felix Klein, Hermann Minkowski, David Hilbert, Edmund Husserl, Woldemar Voigt, and Wilhem Roentgen at the universities of Göttingen and Munich. He graduated from the University of Munich with a thesis under Aurel Voss. Dingler earned his Ph.D. in mathematics, physics and astronomy in 1906. His doctoral advisor was Ferdinand von Lindemann. In 1910 Dingler's first attempt to earn a Habilitation failed. His second try in 1912 was successful. Dingler then taught as a Privatdozent and hold lectures on mathematics, philosophy and the history of science. He became a professor at the University of Munich in 1920. Dingler got a position as Professor ordinarius in Darmstadt in 1932. In 1934, one year after the Nazis took power Dingler was dismissed from his teaching position for still unclear reasons. Dingler himself told several interviewers that this was because of his favorable writings concerning Jews. In fact both philo-semitic as well as anti-semitic statements by Dingler had been noted. From 1934 to 1936 he again held a teaching position. In 1940 Dingler joined the Nazi Party and was again given a teaching position. Of Dingler's 1944 book Aufbau der exakten Fundamentalwissenschaft only thirty copies survived wartime bombing. Thought Dingler's position is usually characterized as "conventionalist" by Karl Popper and others. Sometimes he is called a "radical conventionalist" (also referred to as "critical voluntarism" in the secondary literature), as by the early Rudolf Carnap. Dingler himself initially characterized it as "critical conventionalism", to contrast it with the "naïve conventionalism" of other philosophers such as Poincaré, but he himself later ceased to call his position conventionalist. Dingler agrees with the conventionalists that the fundamental assumptions of geometry and physics are not extracted empirically and cannot be given a transcendental deduction. However, Dingler disagrees with conventionalists such as Henri Poincaré in that he does not believe there is freedom to choose alternative assumptions. Dingler believes that one can give a foundation to mathematics and physics by means of operations as building stones. Dingler claims that this operational analysis leads one to Euclidean geometry and Newtonian mechanics, which are the only possible results. Dingler opposed Albert Einstein's relativity theory and was therefore opposed and snubbed by most of the leaders of the German physics and mathematics community. This