Richard von Mises (1883–1953), the younger brother of Ludwig, had an Apollonian genius. He was a leading probabilist and statistician of the world, a leading engineer and designer of airplanes for the Austro-Hungarian Empire, and a leading philosopher of “positivism.” Von Mises was rational and measured, a man of observations and proportions. Though too modest to say so, he was a hero in his own story of scientific philosophy. A Harvard professor, von Mises was also learned in the humanities: his Positivism: A Study in Human Understanding (Cambridge, MA: Harvard University Press, 1939 [1951]) is painted with images from Nietzsche, Schopenhauer, and Goethe, and in equal proportions with the positivist icons of Mach and Comte and Kant (pp. 401–04). Von Mises owned and loved the world's largest collection of Rilke poetry before bequeathing the collection to Harvard's Houghton library. But von Mises believed his Dionysian self to be rhetorically separable from the positivist-scientist self, and lower. He tried to peel rhetoric away from science and gaze at its logical and empirical clarity. Abraham Wald was his student. His theory of collective probability influenced the econometrics of Trygve Haavelmo. Yet econometricians and philosophers younger than Arnold Zellner have never heard of Richard von Mises.