Since the financial crisis in 2007 at the latest, the Austrian School of Economics has experienced a boom in public attention. By comparison, its reputation within academia is battered. In particular, the radical Neo-Austrian branch is regarded as dogmatic, unscientific, and politically biased. The characteristic feature of this radical wing is the exclusive use of praxeology as the methodology of the theoretical social sciences. Ludwig von Mises was the first to explicate and justify praxeology. The book aims at a rational reconstruction of Mises' position in the philosophy of science.