Ernst Mach (1838–1916), a physicist, sense physiologist and philosopher malgré lui was perhaps the last person to make significant professional contributions in all three fields. Raised outside Vienna, Mach studied physics and sense physiology in the city and taught, first at Graz, and then for most of his career (1867–1894) in Prague. Through his historico-critical studies such as Die Mechanik in ihrer Entwicklung (1883) and Beiträge zur Analyse der Empfindungen (1886), Mach wrote for a world wide audience outside his Prague lecture room: physicists such as Albert Einstein, Wolfgang Pauli, and Erwin Schrödinger; philosophers such as William James, Bertrand Russell, Rudolf Carnap, and Otto Neurath and a host of others, including the economist Friedrich von Hayek and the novelist Robert Musil.¹