Project description

Historical background

On September 28, 1930, a hefty ocean liner arrived at the harbor of New York. One of its passengers was Herbert Feigl, a Viennese philosopher of Jewish descent. In traveling to the new world, Feigl was escaping the increasingly hostile situation in Austria—a country led by a chancellor who had recently supported a cap on Jewish academics. Although Feigl had written an important book about the recent revolutions in physics—a book that had prompted Albert Einstein to write him a recommendation letter—he had been unable to find a position in the German-speaking world. In the United States, on the other hand, he hoped to have more success. He had recently received a Rockefeller Fellowship and he was going to spend a year at Harvard, where he would be working with the physicist P. W. Bridgman.

Before his emigration, Feigl had been a member of the Vienna Circle (Wiener Kreis), a group of philosophers and scientists led by Moritz Schlick, best known for his philosophical exposition of relativity theory (Schlick 1917). Other prominent members of the Circle included the mathematician Hans Hahn, the physicist Philipp Frank, and the philosopher-logician Rudolf Carnap. Together, the group had aimed to develop a new, unified theory of scientific knowledge—a much-needed theory since existing epistemologies seemed terribly outdated after the revolutionary developments in the natural and formal sciences (e.g., relativity theory, quantum physics, and modern logic). Building on the empiricism of predecessors such as Ernst Mach, the group had created a new movement, today best known as ‘logical positivism’ (Blumberg and Feigl 1931) or ‘logical empiricism’ (Neurath 1931).

Feigl was not the only scholar to cross the Atlantic in order to escape the hostilities on the continent. In the 1930s, hundreds of mostly Jewish academics sought refuge in the United States (Breitman and Kraut 1987), a development that has often been described as the great intellectual migration. Among them was a small group of Feigl’s former colleagues. Several members of the Vienna Circle (e.g., Carnap, Frank, and Gustav Bergmann) and closely related groups such as the Berlin Circle and the Lvov-Warsaw School (e.g., Hans Reichenbach, Carl Gustav Hempel, and Alfred Tarski) would follow Feigl’s footsteps in the years before the Second World War. And although some of them would soon discover that American academia was not free from anti-Jewish sentiments either—in a letter to Schlick, Feigl reported that “antisemitism has grown colossal here too” (cited in Verhaegh 2020a)—many of them would quickly find positions at U.S. institutions, where they started to spread their new perspective on science and philosophy.

The exiled empiricists had a tremendous impact on the American philosophical community. Whereas the intellectual climate had been dominated by distinctively American schools such as pragmatism in the first decades of the twentieth-century, U.S. philosophers quickly began to develop views that were heavily indebted to the perspective that had originated on the continent. The émigrés and their followers came to dictate discussions in American philosophy journals (Katzav and Vaesen 2017; Verhaegh 2020a) as well as to found new and influential venues for what would soon become known as ‘analytic philosophy’. And because the United States became the dominant academic power in the decades after the war, this changing intellectual landscape strongly affected the course of philosophy outside the U.S. as well. Indeed, it seems safe to say that much of (analytic) academic philosophy today is still shaped by the discussions, practices, and institutions first initiated during this disruptive period.

A socio-historical puzzle

To present-day philosophers who sympathize with scientific approaches to philosophy, it might appear natural that the exiled empiricists had such a big impact on the American intellectual climate. From a socio-historical perspective, however, their success is puzzling for at least three reasons. For one thing, the philosophers emigrated to the United States in the mid-1930s, when academic institutions were plagued by the effects of the Great Depression. The academic job market had collapsed and rapidly shrinking private endowments substantially affected the budgets of American universities (Geiger 2015, ch. 11). While the ports of New York City welcomed hundreds of refugee scholars, there were not even enough jobs for America’s best and brightest. In a letter, the New York philosopher Ernest Nagel wrote that it felt as if “half of Europe” was passing through the harbor and he expressed his despair that so many “splendidly equipped” intellectuals with “harrowing experiences” were arriving in a country that could not offer them “any prospects” (Nagel to Charles Morris, October 20, 1938, Records of the Unity of Science Movement Records, University of Chicago Library). Given this situation, it is remarkable that many empiricists were still able to obtain academic positions at prominent U.S. institutions such as Harvard University (Frank), the University of Chicago (Carnap, Hempel, and Olaf Helmer), and the University of California (Tarski and Reichenbach).

The empiricists’ success is even more puzzling considering the philosophical context. The European refugees arrived in a period that has often been characterized as “The Golden Age of American Philosophy” (Kurtz 1966; Kuklick 2002); a period in which the U.S. intellectual map was dominated by distinctively American traditions such as pragmatism. John Dewey dictated public and philosophical debates in New York (Reisch 2005, 11), the Chicago school of pragmatism was influential throughout the Midwest (Shook and Ryan 2000), and the Harvard professor C. I. Lewis had just published Mind and the World-Order, a book which had reinvigorated pragmatism as the paradigmatically American philosophy (Lewis 1929; Misak 2013). As such, it is surprising that a small group of empiricist refugees was able to put such a mark on postwar American philosophy. For although there were some philosophical and ideological similarities between pragmatism and logical empiricism, there were also strong theoretical tensions. Many U.S. philosophers, including Dewey and Lewis, strongly criticized the Circle’s sceptical views about ethics and metaphysics, whereas the empiricists accused the pragmatists of neglecting modern logic and of defending outdated views about science (Blumberg and Feigl 1931, 282; Dewey 1934; Dewey and Bentley 1949; Nagel 1934; Lewis 1934; 1941; Reichenbach 1939).

Finally, and most importantly, the empiricists’ success is puzzling because they were not the only school of philosophers to seek refuge in North America. In the years before the Second World War, philosophers from a wide range of traditions escaped the perilous situation on the continent. Critical theorists of the Frankfurter Schule (e.g., Theodor Adorno, Max Horkheimer, and Herbert Marcuse) successfully moved their institute to Columbia University and exiled phenomenologists (e.g., Aron Gurwitsch and Alfred Schutz) were promoting their views via the new American journal Philosophy and Phenomenological Research. In addition, there was a lively community of American Neo-Kantians centered around the expatriate philosopher Ernst Cassirer as well as an active group of what Richard Wolin (2001) has called ‘Heidegger’s children’ (e.g., Hannah Arendt, Karl Löwith, and Hans Jonas). Although all of these groups were quite successful in acquiring some American following, the empiricists had by far the biggest impact on academic philosophy (Kuklick 2002, 232), turning the United States into a bastion of ‘analytic philosophy’ after the Second World War. Logical empiricism had been a relatively minor school of thought in Europe, where the philosophical climate was dominated by phenomenology, but the roles were remarkably reversed in the United States. This development also surprised the immigrant philosophers themselves. Arendt, for example, expressed her astonishment in an interview with the New York philosopher William Barrett: “I can’t understand why you Americans have taken to these second-rate European positivists that have come here. In Europe people like Carnap and Hempel were jokes … Here you take them seriously” (cited in Barrett 1982, 104).

Current state of knowledge and central questions

In recent years, there has been quite some attention for the development of logical empiricism in the United States. Hardcastle and Richardson (2003), Reisch (2005), and Pihlström et al. (2017) offer excellent reconstructions of the fate of logical empiricism in North America and historians have provided detailed accounts of the activities of prominent European emigrants like Carnap (e.g., Limbeck-Lilienau 2010; Creath 2012; Verhaegh 2020b); and Reichenbach (Gerner 1997; Padovani 2008; Verhaegh 2020c). Especially the Institute Vienna Circle has published some outstanding volumes on the work of the logical empiricists and the evolution of European philosophy of science more broadly (e.g., Galavotti et al. 2013; Stadler 2015). In addition, the development of related groups such as the Berlin Circle (e.g., Rescher 2006; Milkov and Peckhaus 2013) and the Lvov-Warsaw School (e.g., Wolenski 1989; Coniglione et al. 1993) has been documented by a growing community of historians of philosophy of science.

Something similar can be said about the historiography of immigrants from alternative philosophical traditions. Scholars have published outstanding books about the Frankfurt School in exile (Jay 1986; Wheatland 2009), about the fate of Heidegger’s students (Wolin 2001; Woessner 2011), and about the American reception of Husserlian phenomenology (Ferri 2019). They reconstruct the activities of these diverse groups of refugees and chart, for example, Horkheimer’s connections with the ‘New York Intellectuals’, the development of phenomenology at the New School for Social Research, and the rising fame of émigrés such as Marcuse and Arendt, who became prominent public intellectuals in the decades after the Second World War.

Although these studies offer a wealth of valuable information about the development of these diverse groups of philosophers, they do not provide a comprehensive explanation for the transformation of American philosophy in the wake of the intellectual migration. Most work on the development of American philosophy in this period has been done from the perspective of the incoming refugees. Little attention has been paid to the American context that proved so receptive to the views of the exiled empiricists. Historians do not have a clear overview of the American philosophical landscape in the years before and after the arrival of the European emigrés and, as a result, they have not answered the following questions: (1) What explains the surprisingly positive American reception of logical empiricism? (2) Why were American philosophers more receptive to the views and methods of the exiled empiricists than to the views of alternative schools of philosophical refugees (e.g., critical theory and phenomenology)?


This project aims to answer these questions by shifting the perspective in two ways. First and foremost, this project will approach the problem from a new theoretical angle. Instead of studying a small group of philosophical refugees, it aims to describe and explain the development of the American philosophical community that proved so receptive to their views. The project will flip the perspective, in other words, by studying the intellectual and institutional context that proved so susceptible to the empiricists’ approach. Rather than focusing on the exiled empiricists, phenomenologists, and critical theorists, this project reconstructs how the local, U.S. intellectual climate helped the incoming refugees to succeed. Second, this project aims to shift the perspective by adopting an alternative approach. Typically, historians of philosophy tend to chart the intellectual climate in a particular period by focusing on a small set of big names and by generalizing from them to the entire philosophical community. Historians of the ‘Golden Age of American Philosophy’ tend to focus on prominent philosophers such as Dewey and Lewis and to treat their views as indicative of the U.S. intellectual climate, whereas historians of postwar American philosophy tend to study the work of refugee philosophers such as Carnap and Hempel to chart the main philosophical trends of the 1940s and 1950s. While this approach might be valuable for answering certain types of question, it does not suffice to solve the aforementioned socio-historical puzzle. After all, the popularity of philosophers such as Dewey and Lewis and, after the war, Carnap and Hempel is partly a product of the changing intellectual climate; studying their work alone cannot fully explain why these views became so popular.

In shifting the perspective from the exiled empiricists to the local, American philosophical community, this project offers a new approach toward the study of the history of twentieth-century philosophy of science. In addition, this project has the potential to transcend scholastic boundaries: For one thing, this project asks a comparative question: why were the logical empiricists more successful than the refugee phenomenologists and critical theorists? Whereas previous projects about the development of twentieth-century philosophy tend to stick to the study of one school or philosophical tradition, this project offers a broader, unifying perspective by studying the interplay between a range of intellectual movements. As such, the results of this project will be of interest to all historians of twentieth-century philosophy and have the potential to bridge the gap between distinct communities of historians.

Second, studying the unique American melting pot of philosophical traditions will help us rethink the categories and distinctions that shape academic philosophy today. Present-day philosophy is dictated by a deep divide between ‘analytic’ and ‘continental’ approaches. These labels are notoriously vague (e.g., Glock 2008) but the distinction is so deeply engrained that philosophers working on similar topics are often unaware of each other’s work. Still, few philosophers realize that categories like ‘analytic’ and ‘continental’ are relatively recent inventions, created in the wake of the intellectual migration (Floyd 2009; Frost-Arnold 2017) when U.S. philosophers tried to make sense of the rapidly changing philosophical landscape. Today, it seems obvious to draw a straight line from Russell to Wittgenstein to Kripke; and from Husserl to Heidegger to Sartre. In the 1930s, however, it was still perfectly normal for U.S. philosophers to be interested in Russell and Husserl. The New York philosopher Ernest Nagel, for example, liberally combined views from his U.S. teachers (Dewey and Cohen), the exiled empiricists (Carnap, Reichenbach) and phenomenologists (Felix Kaufmann) in the 1930s (Verhaegh 2021). In addition, he attended a meeting of the Horkheimer Circle. Similarly, Susanne Langer’s work builds on the process philosopher A. N. Whitehead, the logical empiricism of Russell and Carnap, and the neo-Kantian Cassirer (Dengerink Chaplin 2020). Ironically, Langer and Nagel are nowadays viewed as the scholars who coined the term ‘analytic philosophy’ (Langer 1930; Nagel 1936ab).  In studying the transformation of the intellectual climate, this project can help to expose the forces that eventually led philosophers to draw this distinction and shed light on our current philosophical situation by showing that the distinction is historically contingent.

Subprojects and sub-questions

This project is able to shift the perspective because it uses an innovative combination of qualitative and quantitative methods(topic modeling; co-citation analysis; term co-occurrence analysis; concordance analysis; archive study, literature study) and because it uses these methods to examine large sets of mostly unexplored historical data (metadata of American journal publications; archives of American philosophers and scientists; and archival data from American universities and philanthropic organizations). Accordingly, this project is divided into two studies: (A) a bibliometric study which maps the development of U.S. philosophy by computationally analyzing metadata of papers published in American philosophy journals; and (B) a large-scale archival study which qualitatively reconstructs the intellectual and institutional reception of European philosophy by examining dozens of little explored American archives.

Study A: Mapping the development of American philosophy

Big-picture questions require big-data methods. If we are to explain the changes in the American intellectual climate, we need a reliable map of the American philosophical community before and after the intellectual migration; and a detailed description of the changes in this period. Study A aims to chart the development of American philosophy by quantitatively analyzing the 22.521 papers and reviews published in seven American philosophy journals between 1911 and 1960: three generalist journals (Journal of Philosophy, Philosophical Review, and Philosophical Studies), two philosophy of science journals (The Monist and Philosophy of Science), and two journals publishing work in phenomenology and critical theory (Philosophy and Phenomenological Review and Studies in Philosophy and Social Science). This study is divided into three work packages:

  • WP-A1: charts the evolution of American philosophy by generating lists of most-discussed topics and philosophers for every consecutive five-year period between 1911 and 1960.
  • WP-A2: reconstructs the development of philosophical (co-)citation clusters in these periods by creating co-citation networks and by analyzing the overall development of these networks.
  • WP-A3  analyzes how the American philosophical vocabulary developed by studying concordance data and term (co-)occurrence networks.

WP-A1 helps us to answer the question at what point in time and to what extent European philosophers came to play an important role in American philosophy. Although it is known that the main American philosophy journals regularly published discussions about European schools such as logical empiricism (e.g., Ginsburg’s “On the Logical Positivism of the Viennese Circle” and C. I. Lewis’ “Experience and Meaning”) and phenomenology (e.g., Farber’s “A Review of Recent Phenomenological Literature” and Hook’s “Husserl’s Phenomenological Idealism”), work package A1 analyzes the complete set of articles and reviews published in these journals and will therefore be able to track the development of almost the complete American philosophical community. Which philosophers were most prominently discussed? Which topics dominated the philosophical conversation? And, most importantly, how did these trends evolve over time? The first work package employs citation analysis (question 1 and 3) and topic model analysis (questions 2 and 3) to answer these questions.

One important feature of WP-A1 is that it not only collects and analyzes data about the development of American philosophy after the intellectual migration. In studying the most important journals in the 1910s and 1920s, this subproject will also generate data that will help us to determine whether developments before the migration paved the way for the positive reception of logical empiricism in 1930s and 1940s. Some historians have suggested that Cambridge philosophers such as Bertrand Russell and Ludwig Wittgenstein played an important role in putting analytic approaches on the American agenda (Willis 1989; Misak 2016). This is an interesting hypothesis, but as yet, it is not clear whether they had a bigger impact on American philosophy than their continental colleagues Edmund Husserl and Henri Bergson. In charting the most-discussed topics and philosophers in the 1910s and 1920, WP-A1 will also be able to map European influences on American philosophy in a period when these schools were still oceans apart.

WP-A2 will offer further clues when and to what degree European movements became mainstream schools in the United States. The co-citation networks will help us to determine to what extent groups of American philosophers were perceived to be doing work similar to that of the logical empiricists, the phenomenologists, etc. Which co-citation clusters can be identified in the United States before the intellectual migration? Which American philosophers were co-cited with which European philosophers? And how did these co-citation clusters develop after the migration? If the analysis reveals that American and European schools occupied distinct and sharply delineated citation clusters in every consecutive period between 1920 and 1960 but that the ‘logical empiricist’ cluster gradually started to become more prominent because the new generation of American philosophers was more likely to do empiricist work, this will be evidence for what has been called the “eclipse view” (Rorty 1995, 70; Talisse 2007, 133), which suggests that expatriate philosophers gradually outcompeted the pragmatists. If, on the other hand, the analysis reveals that the U.S. pragmatists and the logical empiricists gradually fused into a single citation cluster, this will be evidence for the hypothesis that American pragmatists welcomed the new European philosophers because there were so many similarities between the two world conceptions (Richardson 2002; Misak 2013).

The main advantage of co-citation analysis is that it can be used to track the develop of an entire community of philosophers without relying on controversial school classifications. Because school labels such as ‘pragmatism’ and ‘logical empiricism’ are vague, historically contingent, and change in meaning over time, it is impossible (even misleading) to try and devise clear-cut definitions of when exactly a philosopher uses a pragmatist or a logical empiricist approach. Although most historians agree that there are some archetypical logical empiricists (e.g., Carnap and Reichenbach) or pragmatists (e.g., James or Dewey), it does not make sense to try and divide a community of hundreds of scholars into such strictly delineated categories. Instead of relying on controversial classification criteria, co-citation analysis clusters authors who are regularly cited together by the total academic community. Starting from the assumption that two philosophers who are viewed as doing similar work (e.g., Hempel and Nagel) are frequently co-cited and that two philosophers who are perceived to be using different approaches (e.g., Arendt and Quine) are less frequently co-cited, we can study clusters of frequently co-cited authors over time and map the transformation of American philosophy without relying on strict definitions of when someone does and does not count as a pragmatist or a logical empiricist. The major advantages of co-citation analyses, in other words, is that (1) they are compatible with the idea that school concepts are multidimensional, such that the work of an author can be pragmatist in one sense but empiricist in another; and (2) that they allow that labels change over time. Because we examine which authors were perceived to be doing similar work by a community of citing authors during a clearly delineated period, we can allow that philosophical communities in different periods carve up the field in different ways.

WP-A3: Even if American philosophers did not explicitly cite European philosophers, they might still have been conceptually influenced by continental theoretical frameworks.  Conversely, it also possible that although U.S. philosophers regularly cited European scholars, there was not much integration on a conceptual level. WP-A3 uses term (co-)occurrence and concordance analyses to describe when and to what extent central concepts from refugee frameworks made an entry into the American philosophical discourse. When did key terms from European philosophical schools make an entry in American philosophy? Which terms were employed by which clusters of American philosophers? Did these American philosophers use these terms in the same way? And how did the use of these terms change over time? WP-A3 starts by identifying key terms from the three main schools of philosophical refugees (e.g., the logical empiricists, the phenomenologists, and the critical theorists) and examines when and to what degree these terms started to be used by American philosophers. As such, this study will collect data that can help shed new light on several hypotheses. It has been argued, for example, that pragmatists, under the influence of the logical empiricists, shifted from an experience-based to a language-based approach to empirical meaning (Pihlström 2017). By determining (1) to what extent terms such as ‘experience’, ‘verification’, and ‘meaning’ occurred in papers published by authors in pragmatist co-citation clusters, (2) how frequent these terms were used by pragmatist authors in different time periods, and (3) to what extent papers published by authors in pragmatist co-citation clusters started using terms such as ‘meaning’ in a different way, one can gather new evidence for and against these types of hypotheses.

Study B: Explaining the transformation of American philosophy

Quantitative approaches offer us new and exciting ways to study the history of philosophy. This does not imply, however, that more traditional, qualitative methods (e.g., close reading and archival studies) should be removed from the historian’s toolbox. On the contrary, this project starts from the assumption that it is difficult to explain the development of American philosophy without reconstructing the real-world events behind the networks generated in Study A. Study B, therefore, will investigate these developments by analyzing both the primary literature and a large set of little explored academic archives of a wide range of major and minor players in American philosophy. Whereas Study A generates promising hypotheses about the development of American philosophy—showing, for example, that American philosopher x regularly cited phenomenologist y; or that pragmatist x’ and logical empiricist y’ used similar concepts—study B seeks to explain these connections. This study also comprises three work packages:

  • WP-B1   analyzes the archives of major and minor U.S. philosophers in order to determine to what extent internal developments paved the way for the logical empiricists;
  • WP-B2  examines Euro-American encounters in the 1920s and 1930s in order to determine to what extent external (continental) influences contributed to the positive reception of the refugee philosophers;
  • WP-B3  studies the records of key U.S. institutions (scientific organizations and philanthropic foundations) in order to reconstruct the institutional reception of the philosophical refugees.

WP-B1: In Europe, philosophical reflection on the revolutionary breakthroughs in logic and theoretical physics played a crucial role in the development of logical empiricism. Several central figures of the Vienna Circle and the Berlin Group—e.g., Schlick, Carnap, Feigl, and Reichenbach—made use of the tools of modern logic and acquired their initial fame through analyses of relativity theory and quantum physics. Indeed, historians have shown that these (often neo-Kantian) analyses of the new physics played a pivotal role in the formation of some of logical empiricism’s central commitments (e.g., Richardson 1998; Friedman 1999; Ryckman 2005). Naturally, American philosophers were not blind to these revolutions in logic and physics. American philosophy departments also employed prominent logicians (e.g., Josiah Royce, C. I. Lewis, H. M. Sheffer, and Alonzo Church) and in the years following Eddington’s 1919 confirmation of Einstein’s predictions, American philosophy journals published dozens of analyses of relativity theory.

WP-B1 will analyze the impact of these revolutions on the development of American philosophy and examine to what extent the internal development of U.S. philosophy, too, was affected by these breakthroughs. How did U.S. logicians and philosophers respond to the major breakthroughs in physics and mathematical logic? Can we speak about a distinctively American tradition in logic and the philosophy of science? To what extent did U.S. logicians and philosophers of science influence the development of mainstream philosophical schools like pragmatism? And how similar were these philosophical responses to the ones that were developed in Europe? WP-B1 answers these questions by means of an analysis of the academic archives of several major and minor figures in American philosophy—e.g., Alonzo Church (Princeton University, Firestone Library), Morris Cohen (University of Chicago, Special Collections Center), John Dewey (Johns Hopkins University, Special Collections), Susanne Langer (Houghton Library, Harvard University), Victor Lenzen (UC Berkeley, Special Collections), C. I. Lewis (Stanford University Archives), Henry Margenau (Yale University Archives), George Herbert Mead (University of Chicago), Josiah Royce (University of California, Los Angeles), and Henry Sheffer (Houghton Library) as well as literature from the 1910s and 1920s, thereby reconstructing whether the internal development of U.S. philosophy paved the way for empiricists’ approach. The corpus for work package B1 will be partly determined by the results of Study A but will in any case include the above-mentioned archives and articles on modern logic and relativity theory published in The Journal of Philosophy and the Philosophical Review between 1911 and 1930.

WP-B2: Although U.S. philosophy was dominated by distinctively American intellectual traditions in the first decades of the twentieth century, the academic community was certainly not shielded from philosophical developments across the Atlantic. Prominent European philosophers were occasionally invited for guest professorships and it was customary for America’s best and brightest to spend a year in Europe after obtaining one’s Ph.D. The John Simon Guggenheim Foundation, for example, funded hundreds of young American scholars to spend a year in Europe. Many American philosophers who appear to have played a key role in the reception of logical empiricism (e.g., A. C. Benjamin, Charles Morris, Ernest Nagel, W. V. Quine) visited European centers of philosophy of science in the late 1920s or early 1930s. Similarly, there were many philosophers who went to study with the phenomenologists at Göttingen and Freiburg and the critical theorists at Frankfurt (e.g., Marvin Farber, Charles Hartshorne, and Winthrop P. Bell).

WP-B2 systematically traces the Euro-American contacts in the years before and after the great migration by studying the academic archives of at least fifteen American philosophers who visited Europe between 1920 and 1936: Marvin Farber (1922-24), Charles Hartshorne (1923-25) Ralph Monroe Eaton (1926-27), Sidney Hook (1928-29), Brand Blanshard (1929-30), W. R. Dennes (1929-30), A. Cornelius Benjamin (1930-31), John Daniel Wild (1930-31), Helen Huss Parkhurst (1931-32), W. V. Quine (1932-33), F. S. C. Northrop (1932-33), Susanne Langer (1933-34), Ernest Nagel (1934-35), Charles Morris (1934-35), and C. H. Langford (1935-36). What did they write about before they visited Europe? Which philosophers did they decide to visit? What were their experiences? And what role did they play in the American reception of these European schools after they returned to the United States? Whereas Study A maps the published American discussions about science and philosophy, WP-B2 offers a view behind the scenes by studying the diaries, the fellowship reports, and the academic correspondence of the American philosophers who studied with prominent European philosophers in the years before the migration.

WP-B3: The refugee academics immigrated to the United States in the mid-1930s, when American academic institutions were plagued by the economic effects of the Great Depression. In consequence, the job market for academics collapsed and major philanthropic institutions (e.g., the Rockefeller Foundation, Carnegie Corporation, and the Ford Foundation) started to play an important role in American academia, a development that had already been set into motion in the 1910s, when these foundations gradually began to commit themselves to funding research instead of education (Geiger 2015, ch. 11). Still, many European expatriates were able to find an academic position in the United States and many of them appear to have profited from the philanthropic support of private foundations. Not only did institutions connected to logical empiricism (e.g., the Institute for the Unity of Science, the Minnesota Center for Philosophy of Science, and the Stanford Center for Advanced Study in the Behavioral Sciences) receive external funding, also individual logical empiricists (e.g., Feigl, Carnap, Tarski, Helmer, Hempel, and Edgar Zilsel) benefited from external financial support.

Work packages A1-A3 and B2 analyze the way in which American academics responded to continental intellectual developments and the arrival of the European emigres. As a result, these subprojects mainly focus on the intellectual reception of European philosophy. Intellectual developments do not occur in a social and economic vacuum, however. Any serious analysis of the reception of logical empiricism should also answer the question how it is possible that a good portion of the émigré philosophers were (a) able to get academic positions in an environment plagued by the effects of the Great Depression; and were (b) able to secure substantial amounts of external funding from major philanthropic organizations. WP-B3 will answer these questions and examine the institutional reception of European philosophy in the years before and after the war.

In particular, WP-B3 will (1) use the archival material collected in subprojects WP-B1 and WP-B2 (and, if necessary, new archive material) to study how both major and minor European philosophers were (or, in some cases, were not) able to obtain positions at American institutions, (2) study the records of the ‘big three’ in American philanthropy (Carnegie Corporation, the Rockefeller Foundation, and Ford Foundation) in order to estimate the extent to which projects from European refugees received funding from three major philanthropic organizations; and (3) reconstruct underlying decision-making processes by analyzing documents related to specific grant applications in philosophy at the Carnegie Corporation archives (Columbia University) and the Rockefeller Archive Center (Sleepy Hollow, New York).


This project can only answer the questions it sets out to answer by using an innovative combination of qualitative and quantitative methods. Because this project aims to study the development of an entire community of philosophers, it requires (i) a large amount of data and (ii) advanced bibliometric tools to analyze this data.

Traditionally, historians of philosophy rely on qualitative methods—archive study, close reading, and interpretation—in studying the development of their discipline. Computational historians sometimes claim that qualitative historical research is myopic. They argue that traditional narratives are based on corpora that are not clearly specified (which texts did historians exactly study in arriving at their conclusions?), incredibly small (what percentage of the thousands of texts produced by the community of philosophers did the historians actually read?), and not representative (how can historians guarantee that the texts they read are a representative sample of the total body of texts produced by the community?). In response, traditional historians might argue that purely computational history is empty. Not only are citation networks, topic models, and term occurrence statistics useless if they are not analyzed by scholars with domain expertise—i.e. by historians who have a deep understanding of the texts produced by the community under investigation—many of the hypotheses generated by these computational analyses can only be tested by sound qualitative research. It is for these reasons that the present project will combine quantitative and qualitative tools and methods. Study A relies on a large set of (meta)data from U.S. journals and a range of computational methods (topic modelling; (co-)citation analysis; and concordance analysis), Study B uses archival data and qualitative methods to ensure that the numbers and networks generated by the former projects are carefully interpreted, that the hypotheses generated by the projects are independently tested, and that the real-world developments behind the statistics are minutely reconstructed.

Data, data collection, and data preparation

Journal metadata: Work packages A1-A3 make use of journal (meta)data from seven American philosophy journals. This data will be collected via JSTOR, which contains metadata and full-text OCR files of all seven journals between 1911 and 1960. The project will use JSTOR Data for Research—a free online service available for researchers—to collect metadata (including references), word counts, bi-grams, and tri-grams for all 22.521 papers and reviews published in these journals between 1911 and 1960. After obtaining this data set, it will be cleaned (e.g., by correcting errors, and by removing duplicate papers) and standardized (e.g., by normalizing author names). The resulting data set will also be incredibly useful for scholars who are not working on the history of philosophy of science (e.g., historians working on the development of alternative philosophical traditions such as phenomenology; historians who are interested in the role female scholars played in mid-twentieth century academia; or sociologists of science who are interested in the development of citation practices in philosophy). In order to facilitate the use of this data (and to facilitate replication studies), this project will join existing initiatives to create open access datasets.

Archive data: Study B mostly relies on data from academic and non-academic archives located in the United States. Because it is one of the main aims of the present project to study the way in which European philosophers affected the American intellectual community, the archival projects WP-B2 and WP-B3 will study not only the academic archives of canonical scholars who are still widely studied by present-day historians (e.g., Dewey, Lewis, and Quine) but also philosophers who are less well known today but appear to have significantly contributed to the changing academic climate (e.g., Cohen, Hook, Morris, Northrop, and Sheffer).

Data processing and analysis

Study A relies primarily on computational approaches (topic modeling; (co-)citation analysis; term (co-)occurrence analysis; concordance analysis), whereas Study B relies on archive study, close reading, and conceptual analysis. Both clusters of methods will be discussed in turn.

Topic model analysis:  Topic modeling is a type of text mining that uses probabilistic machine learning techniques to find patterns in corpora of texts. A topic model ‘identifies’ clusters of words that best characterize those texts. The word count data obtained via JSTOR Data for Research provides us with a list of words and corresponding wordcounts for all 22.521 publications in our data set. This collection of lists of pairs of words and numbers will be the input of the model. The output is (1) a term probability distribution over topics and (2) a topic probability distribution over texts, indicating (intuitively) the chance that each word and article ‘belongs’ to each identified topic. These distributions can be analyzed to identify, for example, whether certain topics started to become more prominently discussed in the years before and after the intellectual migration. An important advantage of this method is that it does not require the researcher to manually classify (a sample set of) texts. As such, there is little risk that the researcher imports preconceived categories into the classification. The researcher’s influence mostly comes in after the models have been generated (e.g., in interpreting the topics or in choosing between different models).

(Co-)citation analysis: Citation links reflect the frequencies with which scholars cite each other; co-citation links reflect the frequencies with which authors are cited together in external publications. In order for two academics to be strongly co-cited, a large number of scholars must cite their publications in the same document. As such, in measuring co-citation strength, one measures the degree of association as perceived by the population of citing authors (Small 1973).

In work package WP-A2, we will generate both citation and co-citation networks for different time periods using the free software VOSviewer (Van Eck and Waltman 2010). This software enables the user to import records from, among others, JSTOR and to visualize the links that exist between authors that occur in these records. To create co-citation networks for these authors, the association strength for each pair of authors is calculated as a measure of similarity (Van Eck and Waltman 2009). To map the association strengths between all authors onto a two-dimensional space, the VOSviewer software uses the visualization of similarities method, which is similar to the more widely known method of multidimensional scaling. The overall structure of the networks will be analyzed visually, but we will also make more precise comparisons by tracking how the strengths of specific links between (clusters of) scholars change over time. To test the robustness of the generated clusters, we will compare networks of different sizes (e.g., networks of the top-200, the top-800, and the top-3.200 most-cited authors) and with different parameter settings (e.g., different minimal cluster sizes and different clustering resolutions).

Term (co-)occurrence analysis, keyword analysis and term concordance analysis: The conceptual development of American philosophy (WP-B3) will be analyzed by counting term occurrences and by creating term co-occurrence networks. First, we will use co-occurrence networks to broadly explore the concepts used in American philosophy. These networks provide visualizations of which terms tend to be used in proximity to other terms. For the most frequent terms, association strengths will be computed in the same way as for the authors. We use the above-mentioned VOSviewer software to generate term co-occurrence networks employing the same datasets that were used in the topic model analysis. To create the term networks, VOSviewer uses the same mapping and clustering algorithm as for the author co-citation networks.

Next, we will conduct a more focused analysis in order to track the extent to which key terms from refugee philosophical schools gained a foothold in American philosophy departments. We will analyze which terms are distinctive of logical empiricist, phenomenologist, and critical theorist clusters and we track when and who first employed these words in American journals as well as how the use of these words developed over time. In order to determine which words are distinctive of these schools we use keyword analysis to compare the relative frequency of terms between three different corpora for each period—one for each school (based on the sets of papers that are included in empiricist, phenomenologist, and critical theorist co-citation clusters)—and select the statistically significant keywords for each of those schools. Once we have generated these lists of keywords for each school, term concordance analysis will be employed to determine to what extent American philosophers used these keywords in the same way as the European refugees.

Archive study: Although bibliometric techniques add a very interesting new set of tools to the historian’s toolbox­—allowing historians of science and philosophy to generate new hypotheses and to answer new types of questions—one cannot take the results of such projects at face value. In the proposed project, work packages B1-B3 will enrich the quantitative analyses of journal metadata with substantive study of academic and institutional archives. In work packages B1 and B2 we will study the academic archives of major and minor American philosophers. These studies will be focused on particular types of archival documents. In WP-B2, for example, we will be interested in (1) the fellowship proposals of the American philosophers who visited Europe between 1920 and 1936, (2) notebooks and correspondence from the one or two-year period in which each of these philosophers visited Europe, and (3) the reports they wrote about these trips for the organization that funded the research visit (e.g., the John Simon Guggenheim Foundation) after their return to the United States.  In WP-B1, on the other hand, we will be mostly interested in (1) teaching material (which reveals how up to date these scholars were about developments in logic and physics), (2) correspondence with European physicists and mathematicians, and (3) notebooks and annotated publications (which show how American scholars responded to work of their continental colleagues). Work package B3, finally, will mostly rely on material from the Rockefeller Foundation, the Carnegie Corporation, and the Ford Foundation, including, among others, (1) project applications from philosophers, (2) reports from field officers of these organizations, and (3) minutes from grant application committee meetings.


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