Vienna Circle Institute Library

Transcription

1 Vienna Circle Institute Library Volume 4 Series editor Friedrich Stadler University of Vienna, Institute Vienna Circle, Wien, Austria

2 Institut Wiener Kreis Society for the Advancement of the Scientifi c World Conception Advisory Editorial Board: Jacques Bouveresse, Collège de France, Paris, France Martin Carrier, University of Bielefeld, Germany Nancy Cartwright, London School of Economics, UK Richard Creath, Arizona State University, USA Massimo Ferrari, University of Torino, Italy Michael Friedman, Stanford University, USA Maria Carla Galavotti, University of Bologna, Italy Peter Galison, Harvard University, USA Malachi Hacohen, Duke University, USA Rainer Hegselmann, University of Bayreuth, Germany Michael Heidelberger, University of Tübingen, Germany Don Howard, University of Notre Dame, USA Paul Hoyningen-Huene, University of Hanover, Germany Clemens Jabloner, Hans-Kelsen-Institut, Vienna, Austria Anne J. Kox, University of Amsterdam, The Netherlands Martin Kusch, University of Vienna, Austria James G. Lennox, University of Pittsburgh, USA Juha Manninen, Helsinki Collegium for Advanced Studies, Finland Thomas Mormann, University of Donostia / San Sebastián, Spain Edgar Morscher, University of Salzburg, Austria Kevin Mulligan, Université de Genève, Switzerland Elisabeth Nemeth, University of Vienna, Austria Julian Nida-Rümelin, University of Munich, Germany Ilkka Niiniluoto, University of Helsinki, Finland Otto Pfersmann, Université Paris I Panthéon Sorbonne, France Miklós Rédei, London School of Economics, UK Alan Richardson, University of British Columbia, CDN Gerhard Schurz, University of Düsseldorf, Germany Peter Schuster, University of Vienna, Austria Karl Sigmund, University of Vienna, Austria Hans Sluga, University of California at Berkeley, USA Elliott Sober, University of Wisconsin, USA Antonia Soulez, Université de Paris 8, France Wolfgang Spohn, University of Konstanz, Germany Thomas E. Uebel, University of Manchester, UK Pierre Wagner, Université de Paris 1, Sorbonne, France C. Kenneth Waters, University of Minnesota, USA Jan Woleński, Jagiellonian University, Cracow, Poland Gereon Wolters, University of Konstanz, Germany Anton Zeilinger, University of Vienna, Austria Editorial Address: Institut Wiener Kreis Universitätscampus, Hof 1 Spitalgasse 2-4, A 1090 Wien, Austria Tel.: +431/ (international) or 01/ (national) Fax.: +431/ (international) or 01/ (national) ivc@univie.ac.at Homepage: The titles published in this series are listed at the end of the volume. More information about this series at

3 Friedrich Stadler The Vienna Circle Studies in the Origins, Development, and Influence of Logical Empiricism

4 Friedrich Stadler Institut Wiener Kreis University of Vienna Vienna, Austria Abridged and revised edition of The Vienna Circle (Springer-Wien-New York: 2001). ISBN ISSN Vienna Circle Institute Library ISBN DOI / ISBN (ebook) Library of Congress Control Number: Springer Cham Heidelberg New York Dordrecht London Springer International Publishing Switzerland 2015 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Printed on acid-free paper Springer International Publishing AG Switzerland is part of Springer Science+Business Media (

5 Fig. 1 Entrance to the Mathematical Seminar at the University of Vienna, Boltzmanngasse 5. Meeting place of the Vienna Circle (Schlick Circle)

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7 For Ivich, Serena and Mira

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9 Preface The first edition of this book, The Vienna Circle, that was published in 2001 with Springer (Wien-New York) is now out of print. I have thus decided to have this second edition published as a revised and abridged version in the series Vienna Circle Institute Library (Springer: Dordrecht-Heidelberg-London). Another incentive was the first big exhibition on the Vienna Circle that will be taking place in the main building of the University of Vienna, which is celebrating its 650th anniversary this year. The first three chapters on the prehistory of the Vienna Circle in the context of Austrian philosophy were omitted in this edition, while new research literature as well as primary sources were added. The core text was copyedited again in order to improve legibility. The bio-bibliographic parts have been revised and slightly reconfigured. The website of the Institute Vienna Circle regularly provides further information on current research on the Vienna Circle/Logical Empiricism. I am grateful to Dr. Christoph Limbeck-Lilienau for his research and copyediting work together with Martin Strauss and Robert Kaller for his technical support enabling this second edition, who are both affiliated with the Institute Vienna Circle. I would also like to thank the publisher Springer (Dordrecht), especially Lucy Fleet, for the good long-standing cooperation. Vienna, Austria January 2015 Friedrich Stadler ix

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11 Contents... xv 1 The Origins of Logical Empiricism Roots of the Vienna Circle Before the First World War Mach, Boltzmann, Einstein, and the Vienna Circle Part I The Vienna Circle and Logical Empiricism Between the Wars Emergence and Banishment 2 The Vienna Circle and Logical Empiricism in the First Republic The Sociocultural Framework: The Late Enlightenment The Non-public Phase of the Vienna Circle The Formative Years : Hans Hahn The Actual Founder of the Vienna Circle The Institutionalization of the Schlick Circle : Between Tractatus and Structure The Public Phase of the Vienna Circle: From 1929 Until the Anschluss The Internal Development of Logical Empiricism The Schlick Circle Overview and Documentation of Its Scientific Communication The External Development of Logical Empiricism Until the Anschluss The Ernst Mach Society ( ) The Manifesto The Scientifi c Conception of the World. The Vienna Circle (1929) The First International Meeting Prague xi

12 xii Contents The Lectures Presented at the Ernst Mach Society A Commentary on the Popularization of the Scientific World Conception Internationalization and Emigration Since Karl Menger s Vienna Circle: The Mathematical Colloquium The Mathematical Colloquium and Three Lecture Series The Principle of Logical Tolerance The Relativization of the Dichotomy of Analytic and Synthetic Propositions Wittgenstein, Brouwer, and the Vienna Circle Karl Menger and Kurt Gödel The Genius as Seen by His Mentor The Mathematical Colloquium and Three Lecture Series A Survey of Scientific Communication Wittgenstein and the Vienna Circle: Thought Style and Thought Collective Establishing Contact The Outsider and the Group The Physicalism Dispute: Between Reception and Plagiarism Mentalities: Philosophy and Science as Language-Games Conversations Between Wittgenstein, Schlick, and Waismann: An Overview Preliminary Remark Heinrich Gomperz, Karl Popper, and the Vienna Circle Between Demarcation and Family Resemblance Heinrich Gomperz and the Vienna Circle The Gomperz Circle Discussions (Fragments) The Logic of Scientifi c Discovery in Context Some Remarks on the Popper-Legend Documentation: Popper and the Vienna Circle Excerpt from an Interview with Sir Karl Popper (1991) The Philosophical and Political Pluralism of the Vienna Circle The Example of Otto Neurath and Moritz Schlick The Role of the Universities and Institutes of Adult Education The Demise of Reason The Vienna Circle and the University of Vienna The General Intellectual and Political Situation at the Universities in Vienna The Position of Scientific Philosophy

13 Contents xiii The Political Situation at the Universities in the First Republic Hans Hahn and the Vereinigung sozialistischer Hochschullehrer (Union of Socialist University Teachers) University Politics During the Transition to the Ständestaat The Appointment of Moritz Schlick in Edgar Zilsel s Attempted Habilitation in The Appointment of Hans Eibl and Viktor Kraft in The Appointment to Heinrich Gomperz s Chair in The Appointment to Moritz Schlick s Chair in 1937 and the Resignation of Karl Menger Moritz Schlick and the Dismissal of Friedrich Waismann University, School Reform, and Adult Education Survey: Courses, Seminars and Lectures of Vienna Circle Members Words Divide Pictures Unite : Otto Neurath s Social and Economic Museum, Picture Statistics, and Isotype The Social and Economic Museum in Vienna, The Vienna Method of Picture Statistics and Isotype Picture Statistics and the Political Graphic Art of Constructivism The Vienna Method of Picture Statistics and School Education Visual Education and Adult Education Epilogue: The Exodus of Scientific Reason Part II The Vienna Circle The Biographical and Bibliographical Dimension 11 An Overview of the Vienna Circle The Vienna Circle in Diagrams Register of the Journal Erkenntnis/Journal of Unifi ed Science I VIII ( ) Survey of Contents Schriften zur wissenschaftlichen Weltauffassung, Survey of Contents Einheitswissenschaft Survey of Contents Foundations of the Unity of Science,

14 xiv Contents 12 The Vienna Circle and Its Periphery: Biographies and Biobibliographies The Inner Circle: Biography, Bibliography, Literature The Periphery: Biography, Bibliography, Literature Moritz Schlick s Doctoral Students, Disciples, and Guests in the Context of the Vienna Circle Schlick s Doctoral Students Moritz Schlick s Guests and Associates at the Vienna Circle Documentation: The Murder of Moritz Schlick Editorial Remarks Documents Concerning the Murder of Moritz Schlick - The Prehistory, the Murder Trial, and the Consequences Sources and Literature Published Sources and Literature Bibliographies on Logical Empiricism Used and Quoted Literature Unpublished Sources Personal Conversations and Interviews Photo and Illustration Credits Index of Names

15 Prologue: On the Rise of Scien tific Philosophy An Overview Without a doubt, the work of Bernard Bolzano ( ) marks the beginning of scientific philosophy in the Habsburg Empire. As a representative of Bohemian reform Catholicism with a Josephine spirit, this philosopher, mathematician, theologian, and educator inevitably ran into conflict with the alliance between state and church. Above all on account of his popular edification speeches, Bolzano along with his reformist-utopian social plans was removed from his position as Professor of Religion in the Karl-Universität s philosophy department in 1819 and forbidden to write. 1 From then on, his texts would be published in Austria anonymously, or else in other countries. Nevertheless, through his students, this Bohemian Anti-Kant (also known as the Bohemian Leibniz ) did have a decisive influence on the intellectual life in Austria. This influence is reflected in the Thun-Hohenstein educational reforms, as well as in Frege s rather indirect reception and Kasimir Twardowski s Polish school of logic. Given the fact that the Catholic Habsburg countries German idealism from Kant to Hegel had been repressed, Bolzano could anticipate modern logic and mathematics from Tarski to the Vienna Circle with his objectivist epistemology and his Wissenschaftslehre (1837ff; English edition 1972), especially through his theory of truths and propositions in themselves. The semantic turn of Bolzano s anti-psychologistic philosophy left its stamp on set theory and equally on Karl Popper s Three Worlds doctrine and Gödel s logical realism. Hans Hahn, the Vienna Circle s mathematical mentor, annotated Bolzano s Paradoxes of the Infi nite (1950) ( Paradoxien des Unendlichen (1920)) and, since For an overview of and first introduction to the history of Logical Empiricism in the inter-war years, see Stadler 1982b; Dahms (ed.) 1985; Kruntorad (ed.) 1991; Haller and Stadler (ed.) 1993; Haller 1993; Geier On the intellectual background, see Bradbury and McFarlane (ed.) 1978; Nautz and Vahrenkamp (ed.) 1993; Stadler (ed.) ; Kadrnoska (ed.) 1981; Leser (ed.) 1981; Danneberg et al. (ed.) 1994; Sandner For the book on the chapter s title, see Reichenbach 1951 and Berg and Morscher 1986; Neemann (ed.) 1984; Winter, Berg, Kambartel, Louzil, and van Rootselaar 1969 ff., 9 ff.; Lapointe xv

16 xvi 1913, was engaged in editing his texts together with Alois Höfler. (In Berlin, it was the mathematician Walter Dubislav he committed suicide in Prague in 1937 who was responsible for promulgating Bolzano s ideas.) Within the context of Austrian philosophy, this objectivism and logical realism was taken up chiefly by Franz Brentano and his large circle of students. At the same time, by virtue of his highest ethical maxim Always act so that you serve the common good in the best possible way Bolzano s vision of life and society must be understood in the context of the Enlightenment movement for social reform; he is thus sometimes described as an early socialist. The empiricist philosophical discourse in the tradition of both Bolzano and Leibniz, set off from German idealism, begins in Vienna with Franz Brentano ( ). 2 Through his widespread influence, Brentano served as the mentor for Austrian scientific philosophy, although his thinking still lay in the tradition of rational school-metaphysics. Extending into the twentieth century, the objectivistphenomenological paradigm in Austrian philosophy has its origins with Brentano whose career, like Bolzano s, suffered from the hostility of the Catholic church. Brentano s philosophical deliberations signify a further step in the direction of exact, empirico-logical thought a type of thought carefully oriented toward the individual sciences and aimed at the further development of scientific philosophy. In concrete terms, Brentano s doctrines of intentionality and evidence, along with his critique of language and his analytic metaphysics, were the source of the philosophical realism and language-analysis so basic to the formation of Logical Empiricism. We find this orientation already expressed in one of the central principles in his habilitation-thesis: The true method of philosophy is none other than the method of the natural sciences. 3 In the academic world, this principle was then developed by Brentano s prominent students, including Anton Marty and Thomas Garrigue Masaryk in Prague, Alexius Meinong in Graz, and Kazimierz Twardowski in Lvov. 4 Brentano s work served as a catalyst for Gestalt theory, phenomenology, and language-analysis, but was also taken up by Moore and Russell. We should here particularly take note of the work of Thomas Masaryk, later president of Czechoslovakia, who designated both positivism and critical rationalism as basic elements of his worldview. 5 For this reason, neither his support for Carnap s 1931 appointment in Prague nor his founding of the Brentano-Society with Oskar Kraus in the same year can be considered surprising. And considering that during his stay in Vienna, Masaryk taught Heinrich Gomperz, we can also assume that there was a transfer of his ideas to that city. Karel Capek reports that despite his idealistic inclinations, Masaryk postulated the necessity of a scientific philosophy oriented toward the empirical sciences (1969). We should also note the presence of another multifaceted figure in the con- 2 Baumgartner, Burkard, and Wiedmann (ed.) 1990; Chisholm and Haller (ed.) 1977; Chisholm 1982; Werle 1989; Brentano-Studien 1998 ff.; Smith 1994; Jacquette Franz Brentano, Habilitation thesis 4, in ibid. 1968b, On the history of reception cf. Spiegelberg 1969; Lindenfeld 1980; Dölling 1999; Brozek 2011; Antonelli and David Novak (ed.) 1988.

17 xvii text of Prague s intellectual climate: Christian von Ehrenfels, 6 whose pioneering studies in Gestalt psychology reflected the impact of Brentano, Meinong, and, above all, Mach. Through his writings, von Ehrenfels emerges as an intellectual forerunner of the Berlin School that was to achieve fame through the work of Wolfgang Köhler, Max Wertheimer, and Kurt Koffka. It can be safely assumed that the single most decisive step toward the formation of a scientific philosophy was taken by Ernst Mach ( ) and others in his circle in the course of a general paradigmatic shift to modernism. 7 A genuine polymath, Mach left his mark as a central figure in fin-de-siècle Vienna s intellectual life and, more specifically, as a reformer within the domain of natural science. Narrowly connected with his political praxis, his attempt to establish a historicalsocial and evolutionary foundation for science stood under the sign of the French and English Enlightenment. Mach managed to overcome mechanical materialism through an empirical unity of physics, physiology, and psychology a unity that was received with controversial consequences in the realms of philosophy and the natural sciences, politics, and art. Treated peremptorily as positivism, this epistemology and philosophy of science incorporated a theory of cognitive elements, the methodological principle of economy, and a discussion of the historical-critical method. At the turn of the century, the theory already responded to the challenge of formulating an interdisciplinary scientific world conception with a claim to humanizing and democratizing science and society in a way that was independent of his problematical phenomenalism or realistic empiricism (Banks 2014) a pointed reaction to contemporary metaphysical-systematic philosophy. Mach thus offered the foundation for the formation of the Vienna Circle. The fact that the institution through which the Vienna Circle reached the wider public between 1929 and 1934 was called the Ernst Mach Society correctly reflects his impact. 8 In Berlin, Ludwig Boltzmann s influence would turn out to be stronger than that of Mach. Still, Mach s disciple Joseph Petzoldt did found the Society for Positivist Philosophy in Berlin, which can be considered an early version of the Society for Empirical and Scientific Philosophy, 9 established there in The history of Mach s broad influence can only be sketched in its general developmental lines here: in 1861, he was appointed Privatdozent for physics in Vienna; between 1866 and 1867, he held a chair for mathematics in Graz; and between 1867 and 1895, he held the chair for experimental physics while establishing his international reputation in Prague. In his role as both dean and rector in Prague, Mach was inevitably caught up in the simmering conflicts between the nationalities making up the Habsburg Empire. As an opponent of all nationalism, he struggled without success 6 Fabian (ed.) 1986; Fabian (ed.) 1983 ff. 7 Blackmore 1972; Haller and Stadler (ed.) 1988; Hoffmann and Laitko (ed.) 1991; Blackmore (ed.) 1992; Banks Stadler 1982b, part 2. 9 In addition to the texts by Hoffmann (1993) and Laitko (1993) cf. Hentschel 1990; Milkov and Peckhaus 2013; Milkov 2015.

18 xviii to prevent the university s split into German and Czech divisions and argued for the establishment of an independent Czech institution: as a result of German-national centralism under the Habsburgs, the Bohemianism advocated by Bolzano the peaceful, equal coexistence of the two language-groups had become a minority-position. Prague s cultural life reflected this development. 10 Half of Prague s Germanspeakers representing around 5 % of Prague s population were Jews; forming the sort of subculture evoked by the topos of Kafka s Prague, they played an extraordinarily important role in literature, science, and humanistic scholarship. In this light, it is quite clear that similarly to the situation in Vienna and Berlin the harmonious picture of an enlightened, multicultural, and multiethnic Prague society is to a large extent an aesthetization of coffeehouse culture ; it is a picture that needs adjusting through sober consideration of the real sociocultural circumstances. As indicated, in all three capitals, Jewish life particularly in its assimilated form played a preeminent role. Nevertheless, before World War II, Jewish intellectuals found themselves in a defensive position vis-à-vis the German-speaking population, as a result of the rise of the racist variety of German nationalism. This development would lead, of course, to the catastrophe of emigration, exile, and mass extermination a few decades later. The destruction of a cultural cosmos had its auguries in the fin de siècle. 11 In 1895, Mach was appointed in Vienna to a specially designed chair for philosophy, in particular the history and theory of the inductive sciences. Little time remained before a stroke in 1898 and his retirement as an active scientist 3 years later. A decisive event for the continuity of scientific, antimetaphysical philosophy was the appointment of Ludwig Boltzmann ( ) to the chair created for Mach. 12 Boltzmann was Mach s theoretical counterpart, but contrary to the persistent account never his scientific archenemy. Although the myth of a suicidal battle of giants does not stand up to scrutiny, Mach and Boltzmann did indeed play complementary roles in the tense thematic field between phenomenalism and realism, atomic theory and relativity theory. We also need to recall the crucial role played by Albert Einstein ( ), in both his Prague and Berlin phases, with Mach and Boltzmann in Logical Empiricism s philosophy of natural sciences. This context of intellectual and personal exchange is illuminated by Philipp Frank in his informative biography of Einstein. 13 Einstein s friendship with Frank, enduring into his American exile, is but one manifestation of this much-neglected scientific interaction. From 1912 to his emigration in 1938, Frank, as Einstein s successor in Prague, both experienced and left a distinctive mark on the scientific culture of Central Europe. On an institutional level, one example of the process of cultural continuity involved here is illustrated by the career of Moritz Schlick. Having obtained his 10 On the Prague (ethnic) culture: Brod 1979; Frank Ehalt, Heiß, and Stekl (ed.) 1986; Botstein Broda 1955; Broda (ed.) 1979; Sexl (ed.) 1981 ff.; Stadler and Dahms Frank 1979.

19 xix training in the natural sciences with Max Planck in Berlin, Schlick took over Mach s and Boltzmann s chair in Naturphilosophie in Vienna, serving in that capacity from 1922 until his murder in The liquidation of that chair in 1937 marked a decisive caesura in the rise of scientific philosophy (Reichenbach 1951 and 1954). 14 The impact of this caesura can still be felt today. Crossing disciplinary boundaries, the influence exerted by Mach, Boltzmann, and Einstein is a key to understanding the development of Logical Empiricism well into the post-world War I era. But such genealogies should not obscure the basic fact that in Vienna as well as Berlin and Prague, the movement was a marginal one; especially within the academic realm, it stood opposed to a dominant philosophia perennis that took many forms. Before World War I, beginning as early as 1907, discussions reflecting the work of Mach and focusing on the scientific nature of philosophy in particular, the synthesis of empiricism and conventionalism (Duhem, Poincaré, Brentano, Meinong, Husserl, Helmholtz, Freud) were held in the circle around Philipp Frank, Otto Neurath, Hans Hahn, and Richard von Mises. 15 Following Haller (1986), we can thus speak of a first Vienna Circle serving as a forum for confronting the older positivism. Above all, Frank and Mises offered new interpretations that took account of the modern logic being propounded by Frege, Russell, and (later) Wittgenstein. A scientific-philosophical holism (the non-statement view ), eventually to be taken up by Quine, was developed around Neurath. 16 In the 1930s, a coherence-theoretical consideration and a pragmatic approach to the dynamics of theory had thus already emerged as cornerstones of the physicalist (empirical) International Encyclopedia of Unifi ed Science. Before Carnap himself accepted a variant of the physicalist conception of unified science promoted by Neurath, he had introduced a hierarchical system of scientific concepts in his early masterpiece, Der logische Aufbau der Welt (1928). Formulated along conventionalist lines by means of the theory of types, this system had a phenomenalistic basis: it was formulated in a phenomenalistic language with Machian elements as building blocks and specified their logical relationships by its basic concepts (methodological phenomenalism). 17 Let us note in passing that Carnap was very much aware of the role this logical structure played in the wider social context of art and architecture particularly European New Objectivity (Neue Sachlichkeit). It is thus not surprising that in talks given at the Dessau Bauhaus, both he and Neurath, along with Herbert Feigl, emphasized the close affinities between the scientific world conception and modern social architecture Cf. Chap. 9 as well as Stadler (ed.) 1988; Heiß et al. (ed.) 1989; Fischer and Wimmer (ed.) Frank 1949a, 1 52; Haller 1986, Koppelberg 1987 and 1993; Lauener 1982; Schilpp (ed.) 1991; Creath (ed.) Cf. the texts on Carnap in Haller and Stadler (ed.) 1993; Logic and Language 1962; Schilpp (ed.) 1963; Krauth 1970; Buck and Cohen (ed.) 1971; Hintikka (ed.) 1975; Spohn (ed.) 1991; Carnap 1993; Friedman 1999; Friedman and Creath 2007; Carus Galison 1993 and 1990; Dahms 2004.

20 xx Transparency of construction, intersubjectively intelligible argumentation, and a conscious shaping of one s life represented a common mind-set and reached its theoretical apogee in Neurath s plans. We can recall here the Museum for Society and Economy he founded in Vienna ( ), his development of the Viennese method of pictorial statistics (applying the figurative constructivism propounded by Gerd Arntz and others), and his general engagement in settlement and urban planning. 19 With their manifesto of 1929, The Scientifi c World Conception. The Vienna Circle, the loosely organized group around Moritz Schlick addressed the public for the first time (Stadler and Uebel 2012). At that point, the theoretical pluralism of the new philosophy (Reichenbach) was already apparent against the background of a minimal consensus concerning empiricism, logicism, and their scientific outlook. The reform of philosophy was not expected to result from a unitary, homogenous program of action a program concentrated on one single level. Rather, efforts at such reform could only thrive in an empirical-rational matrix distinguished by an exacting methodology opposed to any cult of genius and philosophical esoterics. As mentioned, Neurath intended the group s official name to underscore its collective orientation as well as its sociohistorical context setting with positive connotations. The history of the Vienna Circle can usually be divided into four phases 20 : 1. The discussion-circle formed by Frank, Hahn, Neurath, and Richard von Mises from 1907 until World War I; at the same time, Richard von Mises organized his discussion-circle in Vienna. 2. The constitutive phase after the war, extending to the start of the Thursdayevening meetings led by Moritz Schlick (1924) during which Hans Hahn played an important role, prompting Frank to name him the real founder of the Vienna Circle. 3. The nonpublic phase from 1924 to 1928, marked by personal contacts with Ludwig Wittgenstein and Carnap s move to Vienna. 4. The public phase inaugurated in 1929 with the publication of the Circle s manifesto, the founding of the Ernst Mach Society, and the first international appearance of the group in the First Conference on Epistemology in the Exact Sciences in Prague. This is the period of regular contacts with Karl Popper. In 1930, the Circle s public role was confirmed with the publication of the journal Erkenntnis, edited jointly by Carnap and Reichenbach. However, the international rise of scientific philosophy was accompanied by the start of a process of inner and outer dissolution: the politically and, for the Nazis, racially determined emigrations from 1933 to 1934 to the outbreak of World War II. The murder of Moritz Schlick was a fitting symbol for the decline of reason within Austria. The last, private, and epigone discussion groups were meetings merely tolerated, before the expulsion of Logical Empiricism from Vienna, Prague, Warsaw, and Berlin, where this process had begun earlier following Hitler s rise to 19 Haller and Kinross (ed.) 1991; Stadler (ed.) 1982; Vossoughian On the periodization, see Chaps. 3 and 4.

21 xxi power. From this point onward, we can speak of a new phase for the movement, now an exiled but essentially successful scientific culture, whose transformation, however, came at the cost of the loss of its original cognitive identity and the destruction of its actual identity. Let us now return to the Vienna Station. 21 Following Hans Hahn s return to Vienna in 1921, he was able to ensure Moritz Schlick s appointment to the chair for philosophy of the inductive sciences, despite considerable resistance. Hahn s own lecture courses treated modern logic, primarily Russell and later, prompted by a guest-professorship in Vienna of the German mathematician Kurt Reidemeister ( ) Wittgenstein s Tractatus logico-philosophicus. (In 1926, with Carnap as the driving force, the Schlick Circle would begin a systematic exegesis of the Tractatus.) With Schlick s appointment, an academic intellectual center now existed for scientific philosophy, around which younger, aspiring students and teachers began to gather. Among the newcomers, we can name Herbert Feigl, Friedrich Waismann, Rudolf Carnap (starting in 1924), Bela Juhos, Heinrich Neider, Josef Schächter, Edgar Zilsel, the mathematicians Felix Kaufmann, Karl Menger, Kurt Gödel, Gustav Bergmann, Heinrich Löwy, and Theodor Radakovic, and (among the youngest) Walter Hollitscher, Rose Rand, and Marcel Natkin. On the group s periphery, the architect Josef Frank merits special mention. In the following years, a series of prominent and less well-known guests came from abroad. These included Alfred J. Ayer, Frank P. Ramsey, Ernest Nagel, Willard Van Orman Quine, Alfred Tarski, Eino Kaila, Arne N ss, Hans Reichenbach, Walter Dubislav, Kurt Grelling, Carl Gustav Hempel, Hasso Härlen, Albert Blumberg, Ake Petzäll, Jörgen Jörgensen, Tscha Hung, and Ludovico Geymonat. We should also note guests occasionally invited from elsewhere in Vienna s intellectual world figures such as Robert Reininger and Kurt Bühler. In a related manner, the broad range of contributions to Erkenntnis was supplemented by the separate publication series Schriften zur wissenschaftlichen Weltauffassung, edited by Frank and Schlick between 1929 and 1937, and Einheitswissenschaft, edited by Neurath between 1933 and A series of international conferences signaled the international breakthrough of Logical Empiricism: the workshops held in Prague in 1929 and 1934 and Königsberg in 1930 and the six large meetings of the International Congress for the Unity of Science between 1935 and 1941 (twice in Paris and in Copenhagen, Cambridge, Harvard, and Chicago). The 1930s were thus distinguished by both internationalization and dissolution. For Frank, the fate of the turning point in philosophy (Schlick) was linked to that of the new democracies. 22 Despite the differences between individuals, it was possible for something like an independent philosophical movement to emerge almost simultaneously in three adjacent countries, through the contacts we have outlined. In Prague, the intellectual groundwork was laid by Mach, Einstein, and Frank; it was not, however, institutionalized, if we leave aside philosophical manifestations within the literary Prague Circle around Max Brod. The trend toward rendering 21 Coffa Frank 1979.

22 xxii the Kantian school-philosophy more scientific was manifest in the growing influence of Helmholtz, Hertz, and Planck (whose position had been turned down by Boltzmann) as well as Petzoldt in Berlin. The many obstacles placed in the path of Schlick s appointments in Rostock and Kiel to which he could call on Einstein and Max Born point to the depth of the academic resistance. By the start of the 1920s, Einstein s relativity theory, with which Schlick had been one of the first to engage philosophically, had become the center of a cultural-political battle. Einstein s own appointment in Berlin in 1913 offers the theoretical framework for Hans Reichenbach s work in that city in the closing phase of the Weimar Republic between 1926 and 1933: the philosophical assimilation and analysis of the most recent discoveries in the natural sciences in the process of a gradual emancipation from the neo-kantianism of Leonard Nelson and the school of Jakob Friedrich Fries. Precisely these roots are apparent in the conventionalism of the early Carnap, writing the first edition of his Aufbau in the first half of the 1920s. After studies in Jena and Freiburg (with Frege among others), he, too, breathed the politically and scientifically revolutionary air of the intellectual metropolis Berlin. From 1920 onward, he corresponded with Reichenbach, with whom he was to meet and engage philosophically many times. A first, joint step in this direction was the conference on scientific philosophy which they organized in Erlangen in 1923 and to which they invited, among others, Paul Hertz, Walter Dubislav, and Moritz Schlick. 23 Excursus. Vienna-Berlin-Prague in a biographical context: Rudolf Carnap, Richard von Mises, Hans Reichenbach, and Edgar Zilsel Let us now consider the historical and systematic spectrum of Logical Empiricism, as exemplified in the careers of three protagonists born in the same year: in the first place, Carnap, in his role as innovator and systematizer of the movement s program. 24 Carnap s project of rational reconstruction traces a clear line of development from his Structure via Logical Syntax to his work on semantics and inductive probability. His simultaneous work on the encyclopedia project could not prevent a rift in the late 1930s with Neurath, the committed empiricist. For Neurath, the semantic turn and the formalist trend of Carnap s thought meant a distancing from the program of unified science and its Enlightenment-grounded values. Both substantive differences and differences of mentality had become apparent already in the priority disputes between Carnap, Neurath, and the mystic Wittgenstein at the start of the 1930s. 25 Prima facie, there was more in common then between Carnap and Reichenbach 26 : both had been activists in the German youth movement (the 23 Thiel Cf. the articles on Carnap in Haller and Stadler (ed.) Also the homage to Carnap in: Hintikka (ed.) 1975, xii xviii. 25 Cf. Hintikka 1993; Haller Also Chap Cf. the articles on Reichenbach in Haller and Stadler (ed.) 1993 and M. Reichenbach and Cohen (ed.) 1978; Kamlah and M. Reichenbach (ed.) 1977 ff.

23 xxiii Wandervogel and the Freideutsche Studentenschaft ), and they shared the vision of democratic socialism. Following the collapse of the political revolution of 1918, Reichenbach and Carnap increasingly devoted their efforts to the revolution in science, since they no longer considered theory and practice to be inevitably linked. This change in focus did not involve a shift in political viewpoints: much later, for instance, Carnap was to be very frank in his criticism of McCarthyism-era America and very open in his sympathies for the Prague spring. Rather, it represented the effort to contribute in a concrete manner to the exit of man from his self-imposed dependency (Kant) within the realm of philosophy and science. Until the period of emigration, such projects for the reform of both society and life in general remained regulative ideals for Carnap and Reichenbach as well as for Edgar Zilsel. 27 In Zilsel s case, this orientation was not only manifest in an engagement with adult education and educational reform in Vienna; above all, it was manifest theoretically in his book-length critiques of the contemporary cult of the genius and in his work on an ideal of objectivity directed against all irrationalism, universalism, and Fascism. While Carnap and Reichenbach were able to slowly make their way into university positions, this was not the case with the more uncompromising Zilsel. His studies of the concept of the genius were as little congenial to the prevalent philosophical sensibility as were his rigorous investigations of the origins of modern science, written during his exile. Zilsel s tragic failure uprooting, pauperization, and finally suicide serves as one symbol of the history of Logical Empiricism; another is offered by the successful academic careers of Carnap and Reichenbach in America. It is noteworthy that all three of these figures were considered as candidates for the Prague professorship. Reichenbach declined in 1931 on account of his identification with Berlin s scientific culture; on the other hand, as Carnap s successors in Prague in 1936 Central Europe s last democratic bastion neither Zilsel nor Neurath managed to get the appointment. (We know from the correspondence that in Vienna, in 1926, Reichenbach was being considered by Schlick for the position that Carnap was to get.) Starting in 1934, the political climate of Prague would itself be poisoned by anti-semitic and Nazi propaganda, as a consequence of which Carnap was to leave in 1936, supported by Charles Morris and Willard Van Orman Quine. 28 Before the Anschluss and the Munich Agreement, the intellectual and physical exodus of Logical Empiricism (here represented by Carnap, Reichenbach, and Zilsel) was prefigured; it is difficult to refrain from speculating on what would have been if history had decided on a victory for reason, rather than its defeat. In its basic thrust, Carnap s Logical Syntax of Language (1934) signifies the birth of the modern philosophy of science. In his Viennese period Zilsel, as well, was formulating his findings in the history and sociology of science; the historicization of the logic of science, cultivated since Feyerabend with reference to Mach, had already been a fact before it disappeared in American exile. Zilsel s essays on the 27 In addition to the contributions on Zilsel in Haller and Stadler (ed.) 1993, cf. Dvorak 1981; Zilsel 1976 and Carnap 1963, 20 34; Creath (ed.) 1990, 107 ff.

24 xxiv role of philosophy in Fascism already contributed significantly to the theoretical battle against Nazi ideology and its fellow travelers. 29 On this level, Zilsel was one of the most adamant champions of modern philosophical materialism, standing opposed to romantic metaphysics and academic philosophy with literary pretensions. In their careers, Carnap, Reichenbach, and Zilsel exemplify basic internal and external elements within Logical Empiricism: an engaged political consciousness with a fundamentally democratic orientation; the significant role of Jewish culture, bringing with it the fate of emigration; the logical-mathematical, combined with the natural-science-centered philosophy and the social-scientific impetus; and finally, the historicization, pragmatization, and naturalization of the philosophy of science that has culminated in present-day debates. As mentioned, Kuhn s influential Structure of Scientifi c Revolutions (1962) was itself written for the International Encyclopedia of Unifi ed Science. As the project s editor, Carnap welcomed the study in the warmest terms. The broad influence that this expanded form of philosophy of science also exerted on the modern social sciences (decision theory and game theory) would merit a separate chapter in history. To round off our biographical remarks on Carnap, Reichenbach, and Zilsel, let us take note of the career of the mathematician Richard von Mises ( ). Commuting between the three Central European capitals, von Mises counts among those proponents of the empiricist conception of science whose work has been undervalued. 30 A connoisseur of Rilke, he pursued his studies in Vienna before teaching in Brünn, Strassburg, and Dresden; between 1919 and 1933, he served in Berlin as professor and director of the Institute for Applied Mathematics that he had founded. Von Mises influence was not only scientific, but also cultural. There were regular gatherings in his house of a Mises circle with members of the scientific and literary avant-garde including Robert Musil, who carefully followed the development of Logical Empiricism from Mach to the Vienna Circle, incorporating it into his theory of the novel. In his book Wahrscheinlichkeit, Statistik und Wahrheit (1928; English trans. 1981), von Mises offered an objective concept of statistical probability that had a decisive impact on the ensuing discussions with Reichenbach and Carnap, as well as on Popper. Together with Reichenbach, he was to go into exile in Turkey in 1933, both figures continuing their teaching and research at the newly founded University of Istanbul and, after their second immigration to America in 1938, both ensuring the continuity of scientific philosophy there: von Mises at Harvard, Reichenbach in Los Angeles. Written during his years in Turkey, Mises Kleines Lehrbuch des Positivismus (1939; English 1951) is somewhat like the Viennese complement to Reichenbach s The Rise of Scientifi c Philosophy (1951; German trans. 1953); together with Kraft s survey (1950), both accounts are useful starting points for explorations of the history of Logical Empiricism. Reichenbach s monograph The Theory of Probability (1949) ( Wahrscheinlichkeitslehre (1935)) and, above all, his Experience and 29 Zilsel R. von Mises and 1990.

25 xxv Prediction provided his entry into the American scientific community. Let us note that it was the 1929 Prague conference that had served as the first venue for the thematization of the statistical epoch (Neurath): introduced by Boltzmann and linked to the issues of probability and causality, this theme subsequently remained a constant focal point for the advocates of scientific philosophy (Stadler 2011). Such activities were reflected not only in individual publications, but also in the common project represented by the journal Erkenntnis.31 The idea of founding an independent periodical had been proposed in by Schlick, Reichenbach, and the Gestalt psychologists Wolfgang Köhler and Kurt Lewin; they created their independent philosophical platform in 1930 by taking over and republishing the Annalen der Philosophie, previously published by Felix Meiner Verlag and edited by Hans Vaihinger and Raymund Schmidt. Erkenntnis represented the widest range of opinions within the Logical-Empirical movement. Its publication history is itself a barometer for the spiritual situation of the age (to borrow the title of Jaspers essay in cultural pessimism). Edited by Carnap and Reichenbach on behalf of Berlin s Society for Empirical Philosophy and Vienna s Ernst Mach Society, this publication was the first forum for scientific philosophy in Austria, Germany, and Czechoslovakia. This philosophy was introduced programatically through Schlick s article The Turning Point in Philosophy : an emphatic survey, inspired by Wittgenstein, of the linguistic turn. That was, however, only one of the editors intentions. In his introduction to the first volume, Reichenbach expressed his aim as follows: To engage in philosophy as a critique of science and to gain those insights into the meaning and significance of human cognition, using scientific-analytic methods, which the philosophy of the traditional schools formulated in ever-new systems and based on an assumed autonomy of reason has sought to gain in vain. 32 Reichenbach considered philosophy as a process of research, of analysis and penetrating inspection, a steadily progressing search for knowledge. 33 While the journal assumed international importance in the following years, soon after the Nazi takeover it and its publishers came under enormous pressure. 34 In the fourth volume of 1934, for instance, Reichenbach and Felix Meiner had to defend themselves against the attacks of Hugo Dingler: in an anti-semitically tinged broadside directed at Einstein and the circles in Vienna and Berlin, Dingler denounced Logical Empiricism as a form of cultural Bolshevism an effort on his part to seize control of the journal. As a result of Reichenbach s past political activities in the socialist student movement and his Jewish origins, Meiner s difficulties became ever greater, so he suggested moving to a foreign publisher. The seventh volume of Erkenntnis ( ) was consequently edited by Carnap alone, and the eighth appeared in as the Journal of Unifi ed Science with the Dutch press of 31 Hegselmann and Siegwart 1992, Reichenbach , Ibid., Hegselmann and Siegwart 1991.

26 xxvi Van Stockum & Zoon, which had been recruited as their press in exile by Otto Neurath after his move to The Hague. It is remarkable that even in the 1950s, the conflict with Dingler found a bizarre continuation both within the academy and in the science policy of Austria s Second Republic. 35 A more salutary continuity was the reestablishment of Erkenntnis in 1975 as an International Journal of Analytic Philosophy, edited by Carl G. Hempel, Wolfgang Stegmüller, and Wilhelm K. Essler. The journal is still being published. Alongside the journal s publication, the public phase of Logical Empiricism was marked, as noted, by the founding of two philosophical societies in Vienna and Berlin. These constituted the organizational basis for both the internal, theoretical communication of the movement and for its cooperative public activities. The inaugural meeting of the Ernst Mach Society, devoted to the promotion of the findings of the exact sciences, took place on November 23, The early phase of this institution can only be properly understood in relation to the social-liberal currents in the First Republic s late Enlightenment, which were also present in the Viennese movement for adult education. The intellectual and political context in which the Ernst Mach Society was placed it extended from the Ethical Society to the Monist Society, to the Verein Allgemeine Nährpflicht, to the Freethinkers was shaped, above all, by the contingencies of the First Republic s conflict-ridden cultural life; it also determined the fate of the Ernst Mach Society. Mainly as a result of the increasing influence of members of the Vienna Circle, above all its president Schlick, the original orientation toward a confrontational stance in the culture wars of the time shifted toward the dissemination of the scientific world conception. Nonetheless, the strong ties of the Society to the left meant its prompt dissolution after February 12, Even Schlick s personal engagement could no longer help (he tried, with all good faith in reason, to appeal to the new authorities). In its lectures and study-groups, the Ernst Mach Society conveyed and practiced a form of democratic science during the 5 years of its active life. The roughly 50 lectures reveal participation of the greater portion of the Vienna Circle and its periphery, along with many other Austrian and foreign natural and social scientists. Despite its political party independence and theoretical plurality, the Society inevitably served as one element of social-democratic Vienna s cultural movement. The participation of Feigl, Waismann, Zilsel, Kraft, Neurath, Kaufmann, and other leaders in adult education and the collaboration of Hahn, Zilsel, and Neurath in Glöckel s movement for educational reform are concrete manifestations of their strong social commitment. Unified science was merely the sharpest instrument a kind of Occam s razor in the struggle against burgeoning irrationalism, metaphysical speculation, and universalistic system philosophy. The Society s program was neither temporally nor personally nor theoretically identical with the Vienna Circle s internal philosophical profile, but through its advocacy of physicalism and unified science and its collective, interdisciplinary orientation, it did offer a strong impetus 35 Kraft 1954, Cf. Wolters 1992 for a more recent assessment of Dingler from a constructivist perspective. 36 Stadler 1982b, 171 f. and Sect