abstract:The Vienna Circle (in ) was an association of philosophers gathered around the University of Vienna in 1922, chaired by Moritz Schlick, also known as the Ernst Mach Society (Verein Ernst Mach) in honour of Ernst Mach. Among its members were Gustav Bergmann, Rudolf Carnap, Philipp Frank, Hans Hahn, Tscha Hung, Victor Kraft, Karl Menger, Richard von Mises, Marcel Natkin, Otto Neurath, Olga Hahn-Neurath, Theodor Radakovic, Rose Rand and Friedrich Waismann.