This essay examines Thomas Kuhn’s education and collaboration with Harvard President James Bryant Conant to consider his evolving view of relations between scholarship and politics. Aspects of Kuhn’s unpublished Lowell Lectures of 1951, correspondence with Philipp Frank from 1952, and Kuhn’s thoughts about general education from 1955 are examined to illustrate Kuhn’s intellectual movement away from the political interests and engagements of his youth and away from the salutary civic roles that Conant intended history of science to play in American education. Kuhn’s conception of what counts as methodological study of science and his conception of scientific communities, firmly separated and insulated from the sociology of public life, are upheld as central for understanding how, despite Kuhn’s formative relationship with the public-intellectual Conant, Kuhn evolved in the 1950s a style of professional scholarship about science that reached its fruition in the Structure of Scientific Revolutions.

Logical empiricism of the 1930s was quite different from logical empiricism as it thrived in the 1950s. This later version is better known in part because it was codified by Thomas Kuhn's influential book The Structure of Scientific Revolutions (1962). Kuhn attacked “that image of science by which we are now possessed” (1962, 1) - an image of theories as logically transparent structures reaching from observations to abstract theory and changing in time by acquiring or modifying concepts and statements. This image of science went hand in hand with logical empiricism's interests in the logical structure of theory and procedures such as explanation and confirmation.

Yet the project that Kuhn attacked was itself very young. Kuhn wrote Structure in the late 1950s after a transformation had taken place, specifically, a narrowing in the scope, of the values and goals of logical empiricism. For Kuhn, logical empiricism was a philosophy of science concerned mainly with logic and using logic to understand science.

If the demise of Frank's institute and influence in the profession helps to explain the eventual dominance of the apolitical, professional agenda in philosophy of science, then some explanatory weight must be placed also on the decline of Charles Morris. As discussed in chapter 2, Morris staked his career on outlining a future science of semiotics that would synthesize the best aspects of logical empiricism and pragmatism and function as an organon for the development of a modern, democratic, and scientifically enlightened world culture. While Frank and the institute were declining, therefore, one might expect that Morris would have come to their aid. But Morris's own star had fallen. Because of his enthusiasm for blending Sheldon's somatotype theory with his philosophical research and the because of widely recognized problems with his major book Signs, Language, and Behavior (1946), Morris had less prestige in philosophy and admiration from his colleagues than he did in the 1930s.

Signs, Language, and Behavior

Morris's goal in Signs, Language, and Behavior was to establish a collection of terms for a future science of semiotic that would analyze sign processes in an objective, behavioristic manner. Examples include, obviously, “sign,” “behavior,” and “denotatum,” as well as other terms that Morris defines on their basis. These include “formator” and “formatum,” “pathic sign,” “descriptor,” “designator,” and “determinor.” One problem with the book was Morris's wooden, passive, and soporific style of writing. Morris's most aggressive critic, Arthur Bentley, could not help but poke fun in this regard:

Like any story, the one told here of the rise and fall of the Unity of Science movement in North America is incomplete. Besides the anticommunist pressures described here, other forces and circumstances surely helped to determine the evolution of philosophy of science through the Cold War. Two explored briefly in this chapter are the decline in North America of so-called public intellectuals and the growth of research universities as the main institutions of intellectual life in North America. Both are connected to Cold War anticommunism, and this chapter introduces them as a frame to examine some commonplaces about logical empiricism and the unity of science as well as contemporary interest in the disunity of science. It also addresses two specific questions raised by this story. One concerns the unique role given to Rudolf Carnap, who is depicted both as a leftist philosopher of science in the 1930s and as a professional, apolitical philosopher during and after the Cold War. The other question is one that will have occurred to many readers long before reaching this final chapter: Can't the depoliticization of philosophy of science in the 1950s, described here as the result of multifaceted forces arising from anticommunist powers, be interpreted better as a development or maturation through which twentieth-century philosophy (finally) acknowledged a fundamental and proper disconnection between philosophical research and political partisanship?

When Morris and Carnap regrouped after Neurath's death and began charting a postwar course for the Unity of Science movement, they were joined by Neurath's old friend Philipp Frank. Morris and Carnap planned to edit the Encyclopedia by themselves, and they met with the University of Chicago Press to plan the next section, to be titled Methods of Science. Frank, meanwhile, would become leader of the Institute for the Unity of Science that, with Morris's help, he re-established in Boston as a center of the movement's activities. At the end of 1947, however, William Malisoff suddenly and unexpectedly died, adding to this mix of projects a struggle for the control of Malisoff's journal, Philosophy of Science, and the young Philosophy of Science Association. This chapter examines three factions that worked variously with and against each other in the wake of Malisoff's death and into the 1950s: Frank and Morris sought to lead the Unity of Science movement in sociological and humanistic directions, while Feigl and Reichenbach pursued more professional and profession-building projects that were independent of both Frank's institute and Malisoff's eventual successor, C. West Churchman. Churchman, finally, positioned himself (and his co-authors) as a critic of logical empiricism who shared some of Dewey's (as well as Neurath's, Frank's, and Morris's) reservations about the formal, “scholastic” future into which logical empiricism seemed to be heading.

Logical empiricists themselves indicated that logical empiricism and the Unity of Science movement had not only intellectual (or narrowly epistemological) ambitions, but also social, cultural, and – broadly construed – political ambitions. In his autobiography, Carnap wrote, “All of us in the [Vienna] Circle were strongly interested in social and political progress. Most of us, myself included, were socialists” (1963a, 23). For most, moreover, their socialist politics or outlooks were in various ways connected to their philosophical projects. Had the Vienna Circle's manifesto, Wissenschaftliche Weltauffassung, written by Carnap, Neurath, and Hans Hahn in 1929, been sooner translated and published in America, the progressive, socialist outlook of logical empiricism might have been better known to American philosophers of science. The manifesto sketched a broad, modernist aesthetic that connected the tasks of eliminating metaphysics, reforming philosophy, and unifying the sciences:

Education was indeed, as Velde put it, “a very fertile field” for anticommunist investigations in the 1950s, if only because so many academics, if they had not actually joined the party, had been sympathetic to communism in the 1930s. Because the University of Chicago and Harvard are private institutions, Charles Morris, Rudolf Carnap, and Philipp Frank were sheltered from some of the anticommunist pressures applied to their colleagues at public institutions. Still, all three experienced various kinds of anticommunist pressures in the late 1940s and early 1950s.

Hearings at the University of Chicago

Morris witnessed two investigations at the University of Chicago, the first in 1935 before Carnap had arrived at the university. That investigation was precipitated by radical students who had distributed revolutionary literature to the city's poor. At the same time, the university's May Day celebration of 1934 drew the press's attention to “the enormous gap that had opened between [the] University's students and the climate of opinion prevailing in the city” (McNeill 1991, 62–63). The university's reputation as a hotbed of radicalism was also fed by the early anticommunist book The Red Network (Dilling 1934). The issue ignited when Charles Walgreen, of drugstore fame, wrote to President Hutchins that he was withdrawing his niece from the college: “I am unwilling to have her absorb the Communist influences to which she is assiduously exposed” (in McNeill 1991, 63).

At the height of the so-called hysteria over communism in the 1950s, the logic of anticommunist accusation and persecution was intricate and subtle. With respect to one's political essence, the logic was binary. As presupposed by Senator McCarthy's famous inquiry – “Are you now or have you ever been a member of the Communist Party?” – one either was or was not loyal to the United States at the time in question. With respect to outward appearances, however, the markers of one's political essence were believed to be often obscured or hidden. For communists within the party, one could be a public communist, such as a candidate in an election or a party officer, or one could work hidden in the party's underground. Albert Blumberg, for example, took both these paths at different times of his career. Outside the party, anticommunist investigators targeted “fellow-travelers” who supported or even participated in communist causes but refrained from officially joining the party. They, too, could be more public or less public about their motives and activities. Some openly supported Moscow or some form of communism, while others were believed to hide their support or disguise it as support for general, populist, and even pro-American causes or institutions. Organizations or events known as “communist fronts” outwardly promoted peace, the arts, or social and economic justice while actively promoting Moscow's interests in the Cold War by recruiting party members or cultivating spies.

In 1952, Frank's institute sponsored a colloquium on “Science and Human Behavior.” The announcement that Frank posted suggests that the meeting was likely to elicit the heat and bluster of the values debate. It specified that

Frank clearly did not want the seminar to become a forum for critics of scientism and took a step to prevent that from happening. “Disagreement with that assumption,” the announcement stated, “can more profitably be presented elsewhere.”

To neo-Thomists, anticommunists, and critics of scientism who exalted human values above the reach of empirical science, Frank was defiant. The goals he pursued with his institute, his campaign to reform and enlighten the Conference on Science, Philosophy and Religion, his proposals for science education, and his continuing interest in discussing dialectical materialism prevented him from joining the patriotic chorus celebrating the transcendence of American or Western social values over those of the Soviets and over merely empirical, scientific knowledge. Frank was out of step with many of his colleagues in philosophy of science, and, as we saw, many of his friends and colleagues fielded questions about him from FBI agents in the early 1950s. As the decade continued, Frank's fortunes did not improve.

As Neurath fended off Kallen's attacks in the last year of his life, he was also immersed in a long and frustrating debate with Carnap. It began in 1942 with a renewed skirmish over the viability of semantics and Tarski's theory of truth. By 1944, it had become exacerbated by a dispute over Neurath's encyclopedia monograph, Foundations of Social Science (Neurath 1944). As we see below in this chapter, Neurath charged Carnap and semantics with metaphysical mischief that had potentially severe political consequences. In some ways, Neurath's complaints against semantics paralleled Kallen's complaints about the Unity of Science movement, and they tended to the same overall historical effect: They helped to widen and sustain a rift within the movement that would later help facilitate logical empiricism's subsequent break with the Unity of Science movement. The debate arrayed Neurath, Frank, and Morris, on the one side, against most other logical empiricists whom Neurath and Frank believed were veering into formal, logical modes of philosophical inquiry that, were they to become dominant, would reduce the practical utility and relevance of philosophy of science.

Carnap and Neurath

Histories of the Vienna Circle usually adopt the view that the circle was intellectually and politically divided into a more radical left, led by Neurath, Carnap, and Hahn (who together wrote the circle's manifesto), and a more conservative right, led by Schlick and Friedrich Waismann.

At the end of 1943, Neurath was managing several problems in the Unity of Science movement. In the midst of war, Kallen's charge had been made (and awaited debate in the pages of Philosophy and Phenomenological Research), Neurath had just resumed his dispute with Carnap about semantics, and the University of Chicago Press tapped its fingers waiting for Neurath and his editors to deliver long-overdue monographs for the Encyclopedia. Earlier in the year, the press had threatened to suspend publication until after the war, but Neurath promised them he would soon produce a monograph. Though it was his own (Neurath 1944) that kept the promise, he hoped that his solution to this problem might be his old friend Philipp Frank, who was slated to write a monograph about philosophy of physics. Frank and Neurath were old friends, but they had corresponded little during the early years of the war. When they reconnected, they were quickly reminded how similarly they felt about scientific philosophy and its future.

The Neurath-Frank Alliance

Like Neurath, Frank especially hoped that the movement would prosper after the war. He kept the faith that it would still be in tune with the times – “I think that the longing for a unified scientific view exists everywhere”; “I think that the prospect for Unified Science in the English speaking countries is not bad.” Frank also shared Neurath's worries about the intellectual direction that logical empiricism was taking.

Dewey's willingness to participate in Neurath's encyclopedia project may seem puzzling. Dewey's lifelong concerns with values and the development of culture seem out of place in the enduring reputation of logical empiricism as a technical, value-free enterprise that took value statements, and ethical theories about them, to be empty noise. In part that reputation derives from Rudolf Carnap, whose early writings, especially, matched Neurath's in their claims for the emptiness of metaphysics and the end of traditional philosophy (see, e.g., Carnap 1959a). While Dewey accepted the movement's rejection of all things unscientific and unintelligent (or “unintelligible,” as he once put it), he was very worried that the empirical, scientific study of values would be mistakenly swept away if logical empiricism came to dominate philosophy and intellectual life. Dewey therefore chose to work with Neurath and the Unity of Science movement in order, he hoped, to prevent such a catastrophe.

In his correspondence with Neurath, Carnap, and Morris about his two contributions to the Encyclopedia, and in those contributions themselves, we can see some of the complexities of this alliance between America's leading philosopher and the new leading philosophers of science. On the one hand, Dewey believed that logical empiricism suffered from certain philosophical faults, but came to learn, it would appear, that his critique was mistakenly based on Ayer's influential Language, Truth and Logic.

In their manifesto, Wissenschaftliche Weltauffassung: Der Wiener Kreis, Neurath, Carnap, and Hahn acknowledged that their philosophical and scientific crusade was both entrenched in the sociological and cultural battles of the day and subject to the vicissitudes of psychology, temperament, and social pressure:

Neurath, Carnap, and Hahn probably never imagined that “the historic developments” of the twentieth century would include a new kind of war, a cold war, that would influence intellectual, social, and economic life around the world. It was not just a few individuals who would opt for professionalism and social and cultural disengagement in ivory towers or on “the icy slopes of logic” but entire communities of intellectuals, including philosophers of science, who moved farther away from “the masses” as specialization, professionalization, and nonpartisan analysis became the norms of postwar intellectual life.

After 1945, in the wake of the war and Neurath's death, the Unity of Science movement and its leaders were subject to pressures that hastened the movement's demise and helped to fashion professional philosophy of science as it flourished in the 1950s and '60s. These pressures can be sorted into three kinds according to their generality and diffusion through Cold War society. The most general concerns intellectual fashions. The beliefs and values that became popular and influential in American and British academic and popular culture after the war specifically opposed some of the Unity of Science movement's basic ideals and methods. One such ideal and method was collectivism. It was attacked in two of the era's most influential books, Friedrich Hayek's The Road to Serfdom (1944) and William F. Buckley's God and Man at Yale (1951). These books attacked social collectivism and praised individualism, and did so to wide audiences both intellectual and popular. Buckley's witty disdain for Ivy League intellectual culture entertained popular readers (many of whom had themselves never attended a college or university), while Hayek's Serfdom was serialized in the popular Reader's Digest.

This mood of anticollectivism illustrated by Hayek and Buckley helped to support the second kind of pressure in play, one more localized to institutions of government, popular media, and education. For when Hoover's FBI, the House Un-American Activities Committee, the American Legion, or local politicians sought out communist professors in American colleges and universities, Hayek's and especially Buckley's books enlightened a largely approving public about the different kinds of un-American ideological perversity rampant inside them.

A philosophy of science that aimed to be engaged in matters of politics and progressive social reform was not unique to the Vienna Circle and the Unity of Science movement in Europe. Prior to and simultaneous with the emigration of the movement to America in the 1930s, several different groups and camps of philosophers – both indigenous and exiled from Europe – pursued reformist and progressive programs that sought, as Engels famously wrote, not only to understand the world but to change it.

The purpose of this and the next three chapters is to survey the landscape of radical philosophy in 1930s America in order both to understand how logical empiricism and the Unity of Science movement were received in North America and to establish a context for understanding how left-leaning projects such as the Unity of Science movement came to be later rejected after the war by an academic establishment that had moved to the political right. In particular, because this landscape of the 1930s was inhabited at one extreme by philosophers who proudly and aggressively proclaimed that the kind of philosophy they practiced was communist, and because all things communist came to be openly persecuted in American society in the 1950s, this survey will help to identify some of the political baggage that later accrued to the Unity of Science movement by association or proximity.