Properly Der Wiener Kreis, a group of philosophers working in Vienna in the 1920s who originated logical positivism.
Its leading members included: Moritz Schlick (1882-1936), Rudolf Carnap (1891-1970), Otto Neurath (1882-1945), Herbert Feigl (1902-1988), Kurt Godel (1906-1978), Friedrich Waismann (1896-1959); with Carl Gustav Hempel (1905-1997) and Hans Reichenbach (1891-1953) as associates in Berlin and Alfred Jules Ayer (1910-1989) in England, and Karl Raimund Popper (1902-1994) and Ludwig Wittgenstein (1889-1951) on its fringes.
The Circle was formally constituted as such in 1929, and dispersed after the German invasion of Austria in 1938, mainly to England and the USA. It published a journal called Erkenntnis.
V Kraft, The Vienna Circle (1969)
The Vienna Circle (German: Wiener Kreis) of Logical Empiricism was a group of philosophers and scientists drawn from the natural and social sciences, logic and mathematics who met regularly from 1924 to 1936 at the University of Vienna, chaired by Moritz Schlick.
The Vienna Circle’s influence on 20th-century philosophy, especially philosophy of science and analytic philosophy, is immense up to the present day.
Among the members of the inner circle were Moritz Schlick, Hans Hahn, Philipp Frank, Otto Neurath, Rudolf Carnap, Herbert Feigl, Richard von Mises, Karl Menger, Kurt Gödel, Friedrich Waismann, Felix Kaufmann, Viktor Kraft and Edgar Zilsel. In addition, the Vienna Circle was occasionally visited by Alfred Tarski, Hans Reichenbach, Carl Gustav Hempel, Willard Van Orman Quine, Ernest Nagel, Alfred Jules Ayer, Oskar Morgenstern and Frank P. Ramsey. Ludwig Wittgenstein and Karl Popper were in close contact to the Vienna Circle, but never participated in the meetings of the Schlick Circle.
The philosophical position of the Vienna Circle was called logical empiricism (German: logischer Empirismus), logical positivism or neopositivism. It was influenced by Ernst Mach, David Hilbert, French conventionalism (Henri Poincaré and Pierre Duhem), Gottlob Frege, Bertrand Russell, Ludwig Wittgenstein and Albert Einstein. The Vienna Circle was pluralistic and committed to the ideals of the Enlightenment. It was unified by the aim of making philosophy scientific with the help of modern logic. Main topics were foundational debates in the natural and social sciences, logic and mathematics; the modernization of empiricism by modern logic; the search for an empiricist criterion of meaning; the critique of metaphysics and the unification of the sciences in the unity of science.
The Vienna Circle appeared in public with the publication of various book series – Schriften zur wissenschaftlichen Weltauffassung (Monographs on the Scientific World-Conception), Einheitswissenschaft (Unified Science) and the journal Erkenntnis – and the organization of international conferences in Prague; Königsberg (today known as Kaliningrad); Paris; Copenhagen; Cambridge, UK, and Cambridge, Massachusetts. Its public profile was provided by the Ernst Mach Society (German: Verein Ernst Mach) through which members of the Vienna Circle sought to popularize their ideas in the context of programmes for popular education in Vienna.
During the era of Austrofascism and after the annexation of Austria by Nazi Germany most members of the Vienna Circle were forced to emigrate. The murder of Schlick in 1936 by a former student put an end to the Vienna Circle in Austria.