In 1910, Rudolf Carnap went to the University of Jena to study philosophy with Frege. However, in 1917, he was called up to fight for the German army on the Russian front in World War I, after which he returned to his studies, gaining his doctorate in 1919 for a dissertation on the nature of space. Afterwards, he was appointed professor at the University of Vienna and became one of the leading spokespersons for the logical positivists. In 1930, he and Reichenbach launched the journal Erkenntnis. In 1936, he moved to Chicago. Toward the end of his life, Carnap worked on probability theory.
