The members of the Vienna Circle (Moritz Schlick, Rudolf Carnap, Philipp Frank, Hans Hahn, Herbert Feigl, Fritz Waismann, Kurt Godel, Otto Neurath and others) are working out a ‘Logical Empiricism'. Following Ernst Mach and Poincaré, but above all Russell and Wittgenstein, all the sciences are treated uniformly. Carnap's Logischer Aufbau der Welt (1928) shows in which direction future systematic work will move. Wittgenstein's Tractatus Logico-Philosophicus (1921) clarified, among other things, the position of logic and mathematics; besides the statements that make additions to what is meaningful, there are the ‘tautologies' that show us which transformations are possible within language. By its syntax the language of science excludes anything that is meaningless from the very beginning.