The Vienna Circle () 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 had an influence on 20th-century philosophy, especially philosophy of science and analytic philosophy.
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.Cp. Stöltzner/Uebel 2006, LII-LXXIX.
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 Johann Nelböck put an end to the Vienna Circle in Austria.
History The history and development of the Vienna Circle shows various stages:Cp. the phases in Stadler 2001. See 579–580 for an overview.
First Vienna Circle (1907–1912) The pre-history of the Vienna Circle began with meetings on the philosophy of science and epistemology from 1907 on, promoted by Philipp Frank, Hans Hahn and Otto Neurath.Cp. Frank 1949, Stadler 2001, Uebel 2000. The expression goes back to Rudolf Haller, "Der erste Wiener Kreis", in: Fragen zu Wittgenstein und Aufsätze zur Österreichischen Philosophie, Amsterdam 1986.
Hans Hahn, the oldest of the three (1879–1934), was a mathematician. He received his degree in mathematics in 1902. Afterwards he studied under the direction of Ludwig Boltzmann in Vienna and David Hilbert, Felix Klein and Hermann Minkowski in Göttingen. In 1905 he received the Habilitation in mathematics. He taught at Innsbruck (1905–1906) and Vienna (from 1909).
Otto Neurath (1882–1945) studied mathematics, political economy, and history in Vienna and Berlin. From 1907 to 1914 he taught in Vienna at the Neue Wiener Handelsakademie (Viennese Commercial Academy). Neurath married Olga, Hahn's sister, in 1911.
Philipp Frank, the youngest of the group (1884–1966), studied physics at Göttingen and Vienna with Ludwig Boltzmann, David Hilbert and Felix Klein. From 1912, he held the chair of theoretical physics in the German University in Prague.
Their meetings were held in Viennese coffeehouses from 1907 onward. Frank remembered:
A number of further authors were discussed in the meetings such as Franz Brentano, Alexius Meinong, Hermann von Helmholtz, Heinrich Hertz, Edmund Husserl, Sigmund Freud, Bertrand Russell, Alfred North Whitehead, Vladimir Lenin and Gottlob Frege.Cp. Stadler 2001, 143–161.
Presumably the meetings stopped in 1912, when Frank went to Prague, to hold the chair of theoretical physics left vacant by Albert Einstein. Hahn left Vienna during World War I and returned in 1921.
Formative years (1918–1924) The formation of the Vienna Circle began with Hahn returning to Vienna in 1921.Stadler 2001, 195–218. Together with the mathematician Kurt Reidemeister he organized seminars on Ludwig Wittgenstein's Tractatus logico-philosophicus and on Whitehead and Russell's Principia Mathematica.
With the support of Hahn, Moritz Schlick was appointed to the chair of philosophy of the inductive sciences at the University of Vienna in 1922 – the chair formerly held by Ernst Mach and partly by Boltzmann. Schlick had already published two important works Raum und Zeit in die gegenwärtigen Physik (Space and Time in contemporary Physics) in 1917 and Allgemeine Erkenntnislehre (General Theory of Knowledge) in 1918.
Immediately after Schlick's arrival in Vienna, he organized discussions with the mathematicians around Hahn. In 1924 Schlick's students Friedrich Waismann and Herbert Feigl suggested to their teacher a sort of regular "evening circle". From winter term 1924 on regular meetings were held at the Institute of Mathematics in Vienna's Boltzmanngasse 5 on personal invitation by Schlick. These discussions can be seen as the beginning of the Vienna Circle.Stadler 2001, 199.
Non-public phase – Schlick Circle (1924–1928) The group that met from 1924 on was quite diverse and included not only recognized scientists such as Schlick, Hahn, Kraft, Philipp Frank, Neurath, Olga Hahn-Neurath, and Heinrich Gomperz, but also younger students and doctoral candidates.Stadler 2001, 199–218. In addition, the group invited foreign visitors.
In 1926 Schlick and Hahn arranged to bring Rudolf Carnap to the University of Vienna as a Privatdozent (private lecturer). Carnap's Logical Structure of the World was intensely discussed in the Circle.
Also Wittgenstein's Tractatus logico-philosophicus was read out loud and discussed. From 1927 on personal meetings were arranged between Wittgenstein and Schlick, Waismann, Carnap and Feigl.For the recording of these meetings see
Public phase – Schlick Circle and Verein Ernst Mach (1928–1934) In 1928 the Verein Ernst Mach (Ernst Mach Society) was founded, with Schlick as its chairman.Stadler 2001, 219–290. The aim of the society was the spreading of a "scientific world conception" through public lectures that were in large part held by members of the Vienna Circle.For an overview of the lectures of the Ernst Mach Society 1929–1932 see Stadler 2001, 342–344.
In 1929 the Vienna Circle made its first public appearance under this name – invented by NeurathFrank 1949, 38. – with the publication of its manifesto Wissenschaftliche Weltauffassung. Der Wiener Kreis (The Scientific Conception of the World. The Vienna Circle also known as Viewing the World Scientifically: The Vienna CircleEdmunds, D. and Eidenow, J. Wittgenstein's Poker: The Story of a Ten-Minute Argument Between Two Great Philosophers, 2001, page 151.) The pamphlet is dedicated to Schlick, and its preface was signed by Hahn, Neurath and Carnap.
The manifesto was presented at the Tagung für Erkenntnislehre der exakten Wissenschaften (Conference on the Epistemology of the Exact Sciences) in autumn 1929, organized by the Vienna Circle together with the Berlin Circle. This conference was the first international appearance of logical empiricism (Neurath coined the term in 1931 in his article "Physikalismus") and the first of a number of conferences: Königsberg (1930), Prague (1934), Paris (1935), Copenhague (1936), Cambridge, UK (1938), Cambridge, Mass. (1939), and Chicago (1941).
While primarily known for its views on the natural sciences and metaphysics, the public phase of the Vienna Circle was explicitly political. Neurath and Hahn were both socialists and believed the rejection of magic was a necessary component for liberation of the working classes. The Vienna Circle linked Karl Marx and Friedrich Nietzsche to their political and anti-metaphysical views, indicating a blur between what are now considered two separate schools of contemporary philosophy – analytic philosophy and continental philosophy.
In 1930 the Vienna Circle and the Berlin Society took over the journal Annalen der Philosophie and made it the main journal of logical empiricism under the title Erkenntnis, edited by Carnap and Reichenbach. In addition, the Vienna Circle published a number of book series: Schriften zur wissenschaftlichen Weltauffassung (Monographs on the Scientific World-Conception, ed. by Schlick und Frank, 1928–1937),In 1934 Karl Popper's Logic of Scientific Discovery was published in this series. Einheitswissenschaft (Unified Science, edited by Neurath, 1933–1939), and later the International Encyclopedia of Unified Science (edited by Neurath, Carnap and Charles W. Morris, 1938–1970).
Disintegration, emigration, internationalization (1934–1938) From the beginning of the 1930s the first signs of disintegration appeared for political and racist reasons: Herbert Feigl left Austria in 1930. Carnap was appointed to a chair at Prague University in 1931 and left for Chicago in 1935.
1934 marks an important break: Hahn died after surgery, Neurath fled to Holland because of the victory of Austrofascism in the Austrian Civil War following which the Ernst Mach Society was dissolved for political reasons by the Schuschnigg regime.
The murder of Moritz Schlick by the former student Hans Nelböck for political and personal reasons in 1936 set an end to the meetings of the Schlick Circle.For documents concerning the murder of Moritz Schlick and the trial against Nelböck see Stadler 2001, 869–909.
Some members of the circle such as Kraft, Waismann, Zilsel, Menger and Gomperz continued to meet occasionally. But the annexation of Austria to Nazi Germany in 1938 meant the definite end of the activities of the Vienna Circle in Austria.Only after the war in 1949 arose the Kraft Circle in Vienna, a successor to the Vienna Circle, under the leadership of Viktor Kraft, a former member of the Vienna Circle. Among the members of this circle was Paul Feyerabend.
With the emigration went along the internationalization of logical empiricism. Many former members of the Vienna Circle and the Berlin Circle emigrated to the English-speaking world where they had some influence on the development of philosophy of science. The unity of science movement for the construction of an International Encyclopedia of Unified Science, promoted mainly by Neurath, Carnap, and Morris, is symptomatic of the internationalization of logical empiricism, organizing numerous international conferences and the publication of the International Encyclopedia of Unified Science.For a chronology of the emigration of the Vienna Circle see Hans-Joachim Dahms, "The Emigration of the Vienna Circle", in: Friedrich Stadler, Peter Weibel (ed.), The Cultural Exodus from Austria, Vienna 1995.
Overview of the members Apart from the central figures of the Schlick Circle the question of membership in the Vienna Circle is in many cases unsettled. The partition into "members" and "those sympathetic to the Vienna Circle" produced in the manifesto from 1929 is representative only of a specific moment in the development of the Circle.Stöltzner and Uebel 2006, XX. Depending on the criteria used (regular attendance, philosophical affinities etc.) there are different possible distributions in "inner circle" and "periphery".
In the following list (in alphabetical order), the "inner circle" is defined using the criterion of regular attendance. The "periphery" comprises occasional visitors, foreign visitors and leading intellectual figures who stood in regular contact with the Circle (such as Wittgenstein and Popper).Cp. Stadler 2001, 573. This list follows the presentation in Stadler 2001, 571ff., including further bio-bibliographical information on all the persons listed.