This is the unabridged version of my contribution to the Bits of History blog (Österreichische Akademie der Wissenschaft – Institute for Quantum Optics and Quantum Information Vienna).
In his retrospective autobiographical remarks, contemplating the peculiarities of his academic studies in post-war Vienna, the thought-provoking and controversial Austrian philosopher Paul K. Feyerabend (1924-1994) liked to fashion himself as a physicist turned philosopher for lack of talent. Such a narrative connected his intellectual trajectory with the biographies of leading members of the Vienna Circle, including the restive outsider, Karl Popper. By the early 1970s, however, most of these thinkers had fallen under Feyerabend’s irreverent critical spear as lunatics of a sort, affected by “a previously unknown form of insanity” in their allegedly self-referential and irrelevant ruminations about science . More likely and importantly, that narrative would have echoed, in Feyerabend’s mind, the outstanding tradition of Viennese scientist-philosophers epitomized by the figures of Ludwig Boltzmann and Ernst Mach. These men were models and champions for Feyerabend as he began his own relentless criticism of the representatives of mainstream trends in the philosophy of science of those years: logical empiricism and critical rationalism.
Indeed, during his formative years in Vienna, both before and after his war service (1942-1945), Feyerabend steeped himself in physics . But it was as a young philosopher of quantum theory that he made a name for himself in the second half of the 1950s, virtually overnight, within academic circles on both sides of the Atlantic .
At the Hamerling-Realgymnasium in Vienna (1932-1942), an educational institution shaped by the social democratic principles of the Austrian School Reform, Feyerabend was a student of Oswald Thomas (1882-1963), a brilliant popularizer of science and an engaging physics and astronomy teacher. This launched young Paul, a rather solitary bookworm who spent long hours with physics handbooks and treatises — including the works of philosophically-inclined scientists such as Dingler, Mach, Duhem and Poincaré — into a more active approach. In fact, as he grew into his teenage years, Paul experimented with self-assembled astronomical equipment, collaborated with research institutions, and even dared to venture into public disputes.
In the aftermath of WW2, after flirting briefly with the humanities, Feyerabend resumed his physics studies at the University of Vienna under Kasimir Graff, Adalbert Prey, Karl Przibram, Theodor Sexl and such charismatic characters as the late Hans Thirring (1888-1976) and Felix Ehrenhaft (1879-1952). The latter had recently returned to Vienna from his forced American exile surrounded by an unsettling allure, due partly to his heterodox views and partly to his contentious demeanor. He would become a particularly significant figure for the Feyerabend of the late 1960s, who had reached the top tier of academic ranks but felt no longer at home in academic philosophy of science.
In the feverish intellectual atmosphere of occupied Vienna, the crutch-wielding veteran and fiercely curious mature student Feyerabend was in a sea of opportunities. On various occasions in Vienna and Alpbach, in events promoted by para-academic institutions such the Österreichisches College [Austrian College Society] or the Institut für Wissenschaft und Kunst [Institute for Science and Fine Arts], Feyerabend had the chance to meet and interact intensively and repeatedly with acclaimed physicists and distinguished philosophers of science of the likes of Erwin Schrödinger (1949-51, 1955), Léon Rosenfeld (1949), Maurice Pryce (1949), Philipp Frank (1950, 1955), and Karl Popper (1948). In addition, as the leading member of a small group of STEM students at the University of Vienna — including Rudolf Goldberger de Buda (1924-1988), Peter Schiske (1924-2012), Heinrich K. Eichhorn (1927-1999), Hans Sagan (1928-2000), and Erich Jantsch (1929-1980) — Feyerabend tried to revive the spirit of the Vienna Circle, this time under the patronage of Victor Kraft (1880-1975), a former senior but peripheral member of the Circle around Mortitz Schlick, and the successor of Boltzmann’s, Mach’s, and Schlick’s Chair at the University of Vienna. Most of the members of this study group, the “Kraft Circle” — also known today as “the Third Vienna Circle”  — would go on to have brilliant academic careers in astronomy, physics or mathematics in North America. Feyerabend steered a similar course, but along a different path.
Feyerabend’s shift from physics to philosophy seems to have been prompted by an intellectual failure combined with a wish to graduate early . His work on a doctoral dissertation tackling a problem in classical electrodynamics turned out to be a dead end. This made him turn temporarily from physics to philosophy — an interest he had cultivated from his earlier youth throughout his university studies — and develop, instead, his Kraft Circle notes into a successful thesis which earned him a PhD in philosophy (1951). Favorable circumstances followed that helped Feyerabend neatly integrate physics and philosophy. Not long after submitting his dissertation, generous scholarships came his way that allowed him to meet none other than Niels Bohr and his research team in Denmark (1951) and to continue his post-doctoral studies at the London School of Economics under Popper’s supervision (1952-53). As Popper developed his meditations on quantum theory, Feyerabend concentrated on von Neumann’s proof and its allegedly crucial implications for alternative approaches to the so-called “Copenhagen Interpretation” of quantum theory.
Feyerabend’s work on the philosophy of quantum theory in the years following his return to Vienna (1953-55), together with his constantly expanding connections in international academia, boosted a skyrocketing career. In less than a decade, it would turn Feyerabend from a private scholar without a stable income in the occupied capital of a peripheral country on the eastern border of Western Europe, dominated both politically and culturally by conservative and confessional forces, into a Full Professor of Philosophy at the University of California, Berkeley (1962), one of the most avant-garde campuses on the American West Coast, and soon to become a center of the radical student protests during the Free Speech Movement era and the Vietnam War.
With the support of Popper, Schrödinger and Pryce, Feyerabend was appointed lecturer in the philosophy of science at the University of Bristol (1955-58), where he exposed the conservative, “positivistic”, attitude of the Copenhagen Interpretation, focused on the quantum theory of measurement, and helped organize the Ninth Symposium of the Colston Research Society (1957). The event brought to Bristol the highest echelon of mid-1950s quantum physics theoreticians, including David Bohm (1917-1992), whose unorthodox attempts to relaunch de Boglie’s hidden-variable hypothesis were then hotly debated. Soon afterward, Bohm became Feyerabend’s colleague and discussion partner at Bristol. Concurrently, Feyerabend also substantially contributed to setting up the “Conference on Philosophical Foundations of Physics”, sponsored by the Minnesota Center for Philosophy of Science. Feyerabend had been introduced to the MCPS director Herbert Feigl (1902-1988) a few years earlier in Vienna (1954), shortly after Feigl, a former student of Schlick and one of the inspirers of the Vienna Circle in the second half of the 1920s, had managed to establish an institution that would become the “headquarters” of logical empiricism in North America. That two-year, double-session conference, held at the University of Minnesota (1957) and at Princeton University (1958), opened the doors of American academia to Feyerabend and led to a visiting appointment at Berkeley (1958-59), which was converted to a permanent position after a few months.
Curiously, both Feyerabend’s final melting away from the philosophy of quantum theory in favor of a more general philosophy of science, and soon afterward his dramatic turnabout to dismiss the latter, were again partly the result of intellectual accidents involving quantum physics. In the first case, Feyerabend’s disappointment with the philosophy of quantum theory was accompanied by his assessment of the fruitful possibilities open in the broader field of methodology of science; in the second case, it inspired a rebellion against normative philosophy of science in general [6, 8, 11].
In the early 1960s, Feyerabend’s promotion to full professor at Berkeley was strongly resisted, obstructed, and generally slowed down by Emilio Segré. A leading figure in the physics department with a deeply-felt interest in the history of science, and a member of a committee charged with revitalizing the philosophy department at Berkeley, the Nobel-prize winner took a stern stance against Feyerabend’s later work on the problems of microphysics. This work put forward a reevaluation of Bohr’s interpretation of quantum theory, understood in its own terms and in contrast to Popper’s critical reading, but one that still encouraged the construction of a novel, alternative, and “realistic”, quantum theory. Segré’s staunchly disapproving reception, which questioned the currency and relevance of Feyerabend’s work, deeply affected Feyerabend’s self-confidence. However, that blow was attenuated by a promising train of thought that Feyerabend had been developing at the turn of the 1960s. It foreshadowed something of a breakthrough within the framework of critical rationalism: combining Popper’s methodological proposal with the metaphysical assumptions behind Bohm’s hidden-variable theory so as to improve Popper’s falsificationism by emphasizing its pluralistic component. The result was Feyerabend’s theoretical pluralism: a methodology for science which insisted on theory proliferation as the best strategy to maximize testability, thereby promoting progress.
Feyerabend devoted the first half of the 1960s to developing this line of research, swimming more and more explicitly against the philosophical stream, trying to cope with insurmountable hurdles and, after a period of transition, landing squarely on the anti-methodological pluralism or methodological anarchism of his most well-known work: Against Method – Outline of an Anarchistic Theory of Knowledge (1975) . The book denounced any attempt to establish the universal scientific method as a timeless, fixed set of necessary and sufficient rules leading to the one true theory. Yet it retained a sense of the heuristic value of historically-contingent “rules of thumb” — to be vindicated in light of contextual, spatio-temporally local, factors and circumstances — to enrich our understanding of nature. Quantum theory still had a role to play in the process. It was a seminar discussion with C. F. von Weizsäcker (1912-2007) in late 1965 that finally convinced Feyerabend of the pointlessness of an abstract approach to the philosophy of science and of the need for more concrete, detailed case studies of significant steps in the history of science. The lecture series on the philosophy of quantum theory he delivered at Stanford University as part of a summer institute for philosophy college teachers , together with the publication of Popper’s reiterated criticism of Bohr’s views (1967), triggered, partly as a frustrated reaction , Feyerabend’s thorough defense of Bohr’s interpretation of quantum theory on historical grounds.
Feyerabend’s concern for quantum theory soon dropped into the background as he turned his attention to episodes in the history of early modern science and of Western rationality — most notably, the Copernican Revolution, the Galileo case, and aspects of ancient philosophy — that served as testing grounds for his now deliberately-adopted historical approach, and as tools for debunking the general philosophy of science. Bohm’s metaphysics revolving around the idea of the qualitative infinity of nature, however, still resonates distinctively behind Feyerabend’s later view of the growth of knowledge as a progressive conquest of abundance . At the turn of the 1980s, when approached in Zurich by a young scholar who introduced himself as a physicist turned philosopher of science, Feyerabend could not help but comment, bluntly and somewhat self-ironically: “Was für ein Abstieg! [What a decline!]”