Paul Feyerabend (1924–1994) initially made a name for himself inthe foundations of quantum theory and as an ardent supporter of KarlPopper’s critical rationalism. He argued that good scienceshould be an attempt to re-interpret experience according to our bestscientific theories, which should be used to correct common knowledgeand everyday language to promote progress. His early work resultedfrom a critical synthesis of Popper’s views on empiricism withWittgenstein’s insights on meaning. Specifically, Feyerabendcombined Popper’s views on testability with Wittgenstein’sinsight that theories determine the meanings of observation sentencesso that the same observation sentences make incompatible observationstatements, depending on which theory is used to interpret them.Feyerabend used these peculiar views to criticize his interpretationof Popper’s empiricism (‘falsificationism’) fromwithin Popper’s broader philosophical framework (‘criticalrationalism’). According to Feyerabend, Popper’sempiricism has a limited validity. It is limited to testingcommensurable theories because it relies on formal relations betweencorresponding predictions deduced from incompatible rivals. Bycontrast, meaning change through scientific revolution renders rivalworldviews, as realistic interpretations of experience, logicallydisjoint (or ‘incommensurable’). Feyerabend proposed ageneral model for testing incommensurable rivals based on conjecturesand novel, theory-laden corroborations as exemplified by the Brownianmotion example. Feyerabend was arguing for theoretical pluralism, andmore tolerance toward new proposals, especially toward new approachesin the foundations of quantum theory, such as David Bohm’s‘hidden variables’.

Feyerabend developed the consequences of his views on meaning andmethod, arguing that scientific progress should be understood to be an‘ever-expanding ocean of alternatives’ while continuing tocriticize falsificationism from within Popper’s criticalrationalist camp – until mid-December of 1967 when Feyerabendhad an epiphany and ‘awoke from his dogmatic slumber’. Inpersonal letters, he dramatically announced he was breaking with thePopperian school. He explained his reasons by generalizing from thelimited validity of falsificationism to the limited validity of allmethodological rules. He also outlined his new“‘position’” to be entitled “AgainstMethod”, according to which “anything goes”. In thisway, Feyerabend reversed himself on realism, from recommendingcorrecting common knowledge and everyday language with science in hisearly work to recommending protecting common knowledge and everydaylanguage from the tyranny of scientism in his later work. He becameone of Popper’s most raucous critics both in methodology and inthe foundations of quantum mechanics. His most famous work,Against Method: Outline of an Anarchist Theory of Knowledge(1975, 1988, 1993), redeploys his early ideas and arguments from hisnew perspective. As he made his ‘historical turn’, heincreasingly focused on transitions in worldviews, such asGalileo’s role in the scientific revolution and the rise ofWestern rationalism. He was seen as a leading cultural relativist whobecame a post-modernist and is celebrated as one of the mostinfluential philosophers of the twentieth century. His denunciationsof Western imperialism, his critique of scientism, his defense of thepursuit of alternative medicine and astrology, and his emphasis onenvironmental issues made him a hero of anti-technologicalcountercultures.

• 1. A Brief Chronology of Feyerabend’s Life and Work
• 2. Feyerabend’s Early Life
  • 2.1 Youth (1924 –1938)
  • 2.2 TheAnschluss (1938)
  • 2.3 The War (1939–1945)
  • 2.4 Post-War Activities (1945–1947)
• 3. Feyerabend’s Turn to Philosophy: The Kraft Circle, Popper and Wittgenstein
  • 3.1 Return to Vienna: University, Alpbach and Popper (1947–1948)
  • 3.2 From Physics to Philosophy: The Kraft Circle, Ehrenhaft’s Effects and Wittgenstein (1948–1952)
  • 3.3 Life at the London School of Economics (1952–1953)
  • 3.4 Return to Vienna (1953–1955)
• 4. Feyerabend’s Early Work: Liberalizing Empiricism
  • 4.1 First Academic Appointment: The University of Bristol (1955–1958)
  • 4.2 The University of California at Berkeley: Early Years (1958–1964)
  • 4.3 The Impact of the ‘Student Revolution’: The Mid to Late Sixties
• 5. Feyerabend’s Later Work: Towards Relativism, but then Beyond It
  • 5.1Against Method (1970–1975)
  • 5.2 The Political Consequences of Epistemological Anarchism:Science in a Free Society (1978)
  • 5.3 Ten Wonderful Years: The Eighties in Berkeley and Zurich
  • 5.4 Feyerabend in the Nineties: “Potentially Every Culture is All Cultures” (1994)
• 6. Conclusion: Last Things
• Bibliography
  • Primary Sources
  • Secondary Sources
• Academic Tools
• Other Internet Resources
• Related Entries

1. A Brief Chronology of Feyerabend’s Life and Work

Feyerabend led an extraordinarily eventful life, interacting directlywith several prominent philosophers and scientists, most notably KarlPopper, Ludwig Wittgenstein, Niels Bohr, and David Bohm, who becamesignificant influences on the development of his views.Feyerabend’s formative development is best seen against thebackdrop of his tumultuous relationship with his mentor Karl Popper,Initially, Feyerabend was an ardent supporter of Popper’sphilosophy of science (‘falsificationism’) and his broaderphilosophy (‘critical rationalism’). In 1962, Feyerabendbegan to criticize falsificationism while continuing to supportcritical rationalism. After an epiphany, in private letters sent onthe 17th of December 1967, Feyerabend broke with Popper’sschool, generalizing from the limited validity of falsificationism to“anything goes” (the limited validity of allmethodological rules). He reversed himself on realism fromrecommending correcting common knowledge and everyday language withscience to protecting common knowledge and everyday language fromscientism, abandoning his earlier project, and beginning his laterwork. He repeatedly redeveloped his views on meaning and method,making them relevant to a broad range of controversial issues, fromhis relativism in political philosophy in the late 1970s and 1980s, tohis post-modernism in the 1990s.

2. Feyerabend’s Early Life

(Unless otherwise stated, page references are toKilling Time: TheAutobiography of Paul Feyerabend (1995), henceforth referred toas“KT”).

2.1 Youth (1924 –1938)

Paul Karl Feyerabend was born into a middle-class Viennese family in1924. Times were hard in Vienna in the nineteen-twenties: in theaftermath of the First World War there were famines, hunger riots, andrunaway inflation. Feyerabend’s family had a three-roomapartment on theWolfganggasse, “a quiet street linedwith oak trees” (p. 11). The first chapters of his autobiographygive the impression of his being a strange child, whose activitieswere entirely centered around his own family, and who was cut off fromneighbors, other children, and the outside world because “[t]heworld is a dangerous place” (p. 15). Between the ages of threeand six, Feyerabend recalls, he spent most of his time in theapartment’s kitchen and bedroom. Occasional visits to the cinemaand numerous stories, especially stories with a magical aura, seem tohave taken the place usually filled by childhood friends. He was asickly child, who ran away from home once when he was five years old(p. 7). When he started school at the age of six, he “had noidea how other people lived or what to do with them” (p. 16).The world seemed to be filled with strange and inexplicablehappenings. It took him some while to get used to school, whichinitially made him sick. But when he did so, his health problems haddisappeared. When he learned to read, he found the new and magicalworld of books waiting for him and indulged himself to the full (p.25). But his sense of the world’s inexplicability took some timeto dissipate—he recalls feeling that way about events during thenineteen-thirties and throughout the Second World War.

Feyerabend attended aRealgymnasium (High School), where hewas taught Latin, English, and science. He was aVorzugsschüler, that is, “a student whose gradesexceeded a certain average” (p. 22), and by the time he wassixteen, he had the reputation of knowing more about physics and maththan his teachers. He was also thrown out of school once.

Feyerabend “stumbled into drama and philosophy” (p. 26) byaccident, becoming something of a ham actor in the process. Thisaccident then led to another, when he found himself forced to acceptphilosophy texts among the bundles of books he had bought for theplays and novels they contained. It was, he later claimed, “thedramatic possibilities of reasoning and… the power thatarguments seem to exert over people” (p. 27) with whichphilosophy had fascinated him. Although he was a philosopher byprofession, he preferred to be thought of as an entertainer. Hisinterests, he said, were always somewhat unfocussed (p. 27).

Feyerabend’s school physics teacher, Oswald Thomas, inspired hisinterest in physics and astronomy. The first presentation Feyerabendgave (at school) seems to have been on those subjects (p. 28).Together with his father, he built a telescope and “became aregular observer for the Swiss Institute of Solar Research” (p.29). He describes his scientific interests as follows:

I was interested in both the technical and the more general aspects ofphysics and astronomy, but I drew no distinction between them. For me,Eddington, Mach (hisMechanics andTheory of Heat),and Hugo Dingler (Foundations of Geometry) were scientistswho moved freely from one end of their subject to the other. I readMach very carefully and made many notes (p. 30).

Feyerabend does not tell us how he became acquainted with another oneof his main preoccupations—singing. He was proud of his voice,became a member of a choir, and took singing lessons for years, laterclaiming to have remained in California in order not to have to giveup his singing teacher. In his autobiography he talks of the pleasure,greater than any intellectual pleasure, derived from having and usinga well-trained singing voice (p. 83). During the Second World War, hisinterest in singing led him to attend the opera together with hismother in Vienna (first theVolksoper, and then theStaatsoper). A former opera singer, Johann Langer, gave himsinging lessons and encouraged him to go to an academy. After passingthe entrance examination, Feyerabend did so, becoming a pupil of AdolfVogel. At this point in his life, he later recalled:

The course of my life was […] clear: theoretical astronomyduring the day, preferably in the domain of perturbation theory; thenrehearsals, coaching, vocal exercises, opera in the evening[…]; and astronomical observation at night […] The onlyremaining obstacle was the war (p. 35).

2.2 TheAnschluss (1938)

Feyerabend tells how, without falling for Adolf Hitler’scharisma, he appreciated Hitler’s oratorial style. Austria wasreunified with Germany in 1938. Jewish schoolmates were treateddifferently, and Jewish neighbors and acquaintances starteddisappearing. He actively participated in the Hitler Youth program (p.38), and yet, Feyerabend maintained that he had no clear view of thesituation:

Much of what happened I learned only after the war, from articles,books, and television, and the events I did notice either made noimpression at all or affected me in a random way. I remember them andI can describe them, but there was no context to give them meaning andno aim to judge them by (pp. 37–8).

For me the German occupation and the war that followed were aninconvenience, not a moral problem, and my reactions came fromaccidental moods and circumstances, not from a well-defined outlook(p. 38).

The general impression given by his autobiography is of an imaginativebut fairly solitary person with no stable or well-defined personality,with a tendency to adopt strange views and push them to the extreme– a tendency that stayed with him throughout his life (p. 39).Given his lack of definite principles, his decisions seem to have beenthe result of a struggle between his tendency to conform and hiscontrariness (p. 40). He was easily persuaded by views before becomingcritical of them in defense of alternatives. Just as when he was achild, events happening around him continued to seem strange, distant,and somehow out of context without a definite framework with which tomake sense of them.

2.3 The War (1939–1945)

As far as his army record goes, Feyerabend claims in his autobiographythat his mind is a blank. And yet, motivated in part by the Waldheimaffair, this is one of the periods he tells us most about. It had deepand long-lasting consequences for his views, his body, and his psyche.Having passed his final high school exams in March 1942, he wasdrafted into theArbeitsdienst (the work service introducedby the Nazis), and sent for basic training in Pirmasens, Germany.Feyerabend opted to stay in Germany to keep out of the way of thefighting, but subsequently asked to be sent to where the fighting was,having become bored with cleaning the barracks! He even consideredjoining the SS, for aesthetic reasons. His unit was then posted atQuelerne en Bas, near Brest, in Brittany. Still, the events of the wardid not register. In November 1942, he returned home to Vienna butleft before Christmas to join the Wehrmacht’s Pioneer Corps.

Their training took place in Krems, near Vienna. Feyerabend soonvolunteered for officers’ school, not because of an urge forleadership, but out of a wish to survive, using officers’ schoolas a way to avoid front-line fighting. The trainees were sent toYugoslavia. In Vukovar, in July 1943, he learned of his mother’ssuicide, but was completely unmoved, and noticeably shocked his fellowofficers by displaying no feeling. In October he was promoted to lancecorporal. In December, his unit was sent into battle on the northernpart of the Russian front. Although they blew up every house in theirpath, they never encountered any Russian soldiers, nor any civilians– with two exceptions. On one occasion, men and women wereherded into a cellar before a grenade was tossed in after them. Onanother, a civilian was shot right in the head. Although his memorywas admittedly strangely selective, these disturbing memories stayedwith him (p. 46).

Feyerabend reports that he was foolhardy during battle, treating it asa theatrical event. He received the Iron Cross (second class) early inMarch 1944, for leading his men into a village under enemy fire andthen occupying it. He was promoted to sergeant in April, and then tolieutenant toward the end of that year (taking command of a company ofseasoned soldiers). At the end of November, having completed hisassignment, he gave a series of lectures at the officers’ schoolin Dessau-Rosslau, near Leipzig. Their theme was the(“historicist”) one that “historical periods such asthe Baroque, the Rococo, the Gothic Age are unified by a concealedessence that only a lonely outsider can understand” (p. 49). Hisdescription of these lectures, and his notebook entries at the time,reveal the influence of Friedrich Nietzsche in their fascination withthis “lonely outsider”, “the solitary thinker”(p. 48).

Having returned home for Christmas 1944, Feyerabend again boarded thetrain for the front, this time for Poland, in January 1945. There,during the retreat, he was put in charge of a bicycle company, only tolose all of their bicycles to the advancing Russians the next day.Although he claims to have relished the role of army officer no morethan he later did that of a university professor, he must have beenquite competent, as in the field he came to take the place of asequence of injured officers: first a lieutenant, then a captain, andthen a major. Eventually, he,

was in command of three tanks; an infantry battalion; auxiliary troopsfrom Finland, Poland, the Ukraine; and masses of German refugees (p.51).

In 1945, he was shot during a heroic act of carelessness (trying todirect traffic, while taking fire from all sides). The surgeryremoving the bullet lodged in his spine left him paralyzed from thewaist down. He spent time in a wheelchair, and then on crutches,before learning to walk with the aid of a cane. The war ended as hewas recovering from his injury, in a hospital in Apolda, a little townnear Weimar, while fervently hoping not to recover before the war wasover. Germany’s surrender came as a relief, but also as adisappointment relative to past hopes and aspirations. He later saidof his stint in the army that it was “an interruption, anuisance; I forgot about it the moment it was over” (p. 111),but he also said that he had to learn to live with awakening in themiddle of the night from reoccurring nightmares in which he had eitherto commit treason or murder (pp. 52–53).

2.4 Post-War Activities (1945–1947)

The war took its toll on Feyerabend. The bullet that was removed fromhis spine left him impotent for the rest of his life (hisautobiography contains amusing descriptions of many subsequent sexualencounters). Although he started off completely ignorant of women, hemarried four times, and had, by his own account, plenty of affairs.But he seems to have been distant not just in his relationship withhis parents, but in some of his marriages too. He hated the slaverylove seemed to imply, but hated equally the freedom achieved by takingevasive action. He got bogged down in cycles of dependence, isolation,and renewed dependence, which only dissolved into a more balancedpattern after many years.

At the end of the war, Feyerabend went to the mayor of Apolda andasked for a job. He was assigned to the education section, given anoffice and a secretary and, fittingly, put in charge of entertainment.In 1946, having recovered from paralysis, he received a statefellowship to return to study singing and stage management for a yearat theMusikhochschule in Weimar. He moved from Apolda toWeimar after about three months. At the WeimarInstitut zurMethodologischen Erneuerung des Deutschen Theaters, he studiedtheatre, and at the Weimar Academy, he took classes in Italian,harmony, piano, singing, and enunciation. Singing remained one of hislife’s major interests. He attended performances (drama, opera,ballet, concerts) at Weimar’sNationaltheater, andlater reminisced about opera stars of the time, recalling debates andarguments about theatre (e.g. the stereotyping of roles and plays)with Maxim Vallentin, Hans Eisler, etc. He also played a small part inthe filmDer Prozeß (1948) directed by therenowned G.W. Pabst. Although, by his own account, he led a full life,he became restless and decided to move.

3. Feyerabend’s Turn to Philosophy: The Kraft Circle, Popper and Wittgenstein

The details of Feyerabend’s developing relationships with Popperand Wittgenstein (and their ideas) frame Feyerabend’sphilosophical development. Feyerabend took Popper and Wittgenstein tobe two of his philosophical father figures (Felix Ehrenhaft wasanother, on Feyerabend and Ehrenhaft, see Collodel 2022 and Shaw2017b). The centerpiece of his early philosophy of science,“Explanation, Reduction and Empiricism” (1962a), is acritical synthesis of Popper’s empiricism withWittgenstein’s insights on meaning, which eventually led to hisbreak with Popper’s school in December 1967.

3.1 Return to Vienna: University, Alpbach and Popper (1947–1948)

Feyerabend returned to his parents’ apartment house inVienna’s 15th district on crutches. Although he planned to studyphysics, math, and astronomy, he initially chose instead to readhistory and sociology at the University of Vienna’sInstitutfür Osterreichische Geschichtsforschung, thinking thathistory, unlike physics, is concerned with real life. However, hequickly became dissatisfied with history and returned to theoreticalphysics. Although he later denied having studied philosophy, hiscollege transcript indicates that he also took classes in philosophyof science in all eight semesters (he also took four consecutiveclasses and completed a practicum in psychology). Together with agroup of science students, who all regarded themselves as far superiorto students of other subjects, Feyerabend invaded philosophy lecturesand seminars. Although this was not his first contact with philosophy,it seems to have been the period that cemented his interest.

At the time, he took the positivist line that science is the basis ofknowledge; that it is empirical; and that nonempirical enterprises areeither logic or nonsense (p. 68). These views would have been familiarfrom the climate of Logical Positivism which found its main root inthe Vienna Circle, a group of scientifically-minded philosophers who,in the nineteen-twenties and thirties sought to deploy the newlyrevitalized formal logic of Gottlob Frege and Russell andWhitehead’sPrincipia Mathematica to represent thestructure of human knowledge. Feyerabend’s youthful scientismmakes quite a contrast with his later criticisms of it.

In August 1948, at the first meeting of the international summerseminar of the Austrian College Society in Alpbach which he attended,Feyerabend met the philosopher of science Karl Popper, who had alreadymade a name for himself as the Vienna Circle’s ‘officialopposition’. (The Austrian College Society had been founded in1945 by Austrian resistance fighters, “to provide a forum forthe exchange of scholars and ideas and so to prepare the politicalunification of Europe” (1978, p. 109). In contrast to theinductivism of positivism, Popper defended deductivism as the logic ofjustification. In his 1934 bookLogik der Forschung, Popperelaborated the straightforward and appealing falsificationist viewthat science is a process of conjecture and refutation. Good scienceshould be characterized as a process of bold conjectures and our bestattempts to refute them. In the 1950s, Feyerabend was an ardentsupporter of Popper’s normative approach and Feyerabend’sphilosophical development was affected tremendously by his tumultuousrelationship with Popper and his views both in general methodology andthe foundations of quantum theory (Collodel 2016; Collodel andOberheim 2020; Kuby 2021; van Strien 2020).

Unfortunately, Popper’s autobiography tells us nothing abouttheir relationship, although he was to be the largest single influence(first positive, then negative) on Feyerabend’s development. Forthose hoping that Feyerabend would have used the occasion of hisautobiography to clarify his turbulent relationship with Popper, it isdisappointing that the book tells us so little about it. ElsewhereFeyerabend tells us that initially when they met in Alpbach in 1948,where Popper presented his “The Aim of Science” (Kuby2021), he

admired [Popper’s] freedom of manners, his cheek, hisdisrespectful attitude towards the German philosophers who gave theproceedings weight in more senses than one, his sense of humor [… and] his ability to restate ponderous problems in simple andjournalistic language. Here was a free mind, joyfully putting forthhis ideas, unconcerned about the reaction of the‘professionals’ (1978, p. 115).

But Popper’s ideas themselves were not especially new toFeyerabend. Viktor Kraft, who taught Feyerabend and supervised hisPh.D. thesis, had been defending deductivism since 1925, and accordingto Feyerabend, falsificationism was something “taken forgranted” at Alpbach. Popper’s ideas, he remarked, werealso similar to those of another Viennese philosopher, LudwigWittgenstein, although “more abstract and anaemic” (1978,p. 116). As early as his 1955 review of Wittgenstein’sInvestigations (his first English publication), Feyerabendsuggested that Wittgenstein’s nominalist and constructivistviews on meaning were less clear renditions of Popper’s views.Popper notoriously took Wittgenstein to be his arch-nemesis inphilosophy (see Edmonds and Eidinow, 2001), who was detracting fromthe credit and attention he should be receiving.

Feyerabend attended the Alpbach symposium another fifteen times, firstas a student, then as a lecturer and seminar chair. He also acceptedthe post of “scientific secretary”, and this he called“the most decisive step of my life” (p. 70). This fatefuldecision answers his self-addressed questions about the origin of hiscareer, his reputation, and his situation at the time of writing hisautobiography since he traced his situation back to it. These annualvisits brought Feyerabend into contact with distinguishedscientists-philosophers such as Erwin Schrödinger (1949, 1953,1955), Léon Rosenfeld (1949), Maurice Pryce (1949), and PhilippFrank (1950, 1955), which allowed him to make a name for himself onboth sides of the Atlantic in the second half of the 1950s as aphilosopher engaged with the foundations of quantum theory andscientific method.

At Alpbach, he was also approached by communists, including theMarxist intellectual Walter Hollitscher, who became his teacher andfriend. Feyerabend resisted Hollitscher’s political argumentsbased on his own “youthful elitism” and “an almostinstinctive aversion to group thinking” (p. 73). But althoughFeyerabend later described himself as having been “a ravingpositivist” at the time, it was Hollitscher, he says, whopersuaded him of the cogency of realism about the “externalworld”. Defending realism became a fundamental concern forFeyerabend, who repeatedly argued that scientific research is andshould be conducted on the assumption of realism, which promotesscientific progress in contrast to positivism and instrumentalism.

Feyerabend developed his early ideas in a fascinating series of paperson problems of empiricism, beginning in 1958 (itself based on his 1951thesis), that argue that realism and pluralism promote scientificprogress and prevent it from stagnating into dangerous ideology. Hecharacterized what good science should be as “An Attempt at aRealistic [Re-] Interpretation of Experience” (1958). Throughouthis early philosophy, he recommended correcting common knowledgeaccording to realistic interpretation of our best scientific theories,until his December 1967 epiphany, when he broke from Popper’sschool and reversed himself on realism, concluding that commonknowledge needs to be protected from scientism (Oberheimforthcoming).

3.2 From Physics to Philosophy: The Kraft Circle, Ehrenhaft’s Effects and Wittgenstein (1948–1952)

At The University of Vienna, Feyerabend was an aspiring physicist. Hestudied physics under Hans Thirring, Karl Przibram, and FelixEhrenhaft, for whom he worked as an assistant. Ehrenhaft was anexperimental physicist known as a fierce and independent critic of allkinds of orthodoxy in physics, who was often dismissed as a charlatanafter his infamous controversy with Millikan on the oil-dropexperiment (Holton 1978, Niaz 2005). Initially, Feyerabend and hisfellow science students looked forward to exposing Ehrenhaft as afraud. By 1949, Feyerabend was working as his assistant in Alpbach,when he witnessed a dispute between Ehrenhaft and the orthodoxy inwhich the former presented his experiments (which Feyerabend hadhelped to set up), while the latter defended their position by usingstrategies that Galileo’s opponents would have been proud of,ridiculing Ehrenhaft’s phenomena as mereDreckeffect:

Only much later did Ehrenhaft’s lesson sink in and our attitudeat the time as well as the attitude of the entire profession providedme then with an excellent illustration of the nature of scientificrationality (1978, p. 111).

Ehrenhaft did not convince the theoreticians, who protected themselveswith an iron curtain of dogmatic belief of exactly the same kind asthat deployed by Galileo’s opponents. All the while, theyremained staunch empiricists, never doubting that science had to beadapted to facts. Feyerabend later commented that the day-to-daybusiness of science, what Thomas Kuhn called “normalscience”, cannot exist without this kind of “splitconsciousness”.

Feyerabend’s experience with Ehrenhaft deeply influenced him inat least two significant respects. First, the impotence ofEhrenhaft’s experimental effects (which Feyerabend had helpedset up) motivated his interest in problems of empiricism, which becamethe main theme in his early philosophy. Why were Ehrenhaft’sexperimental effects impotent? Should they have been? More generally,how should experimental effects be used to test theories and justifytheory choice? These were exactly the kinds of questions to whichPopper’s empiricism provided answers, and which eventually ledFeyerabend to conclude that established theories onlyseemempirically secure when there is a lack of alternative theories thatcould show how they are wrong (Feyerabend 1962a). A second lastinginfluence is demonstrated by Feyerabend’s emphasis on the factthat it is impossible to tell the difference between a charlatan and arevolutionary except in hindsight, which began to play out inFeyerabend’s published papers in the mid-to late-1960s (seeFeyerabend 1964, Collodel 2022, Shaw 2017b), but only fully came tofruition in conjunction with his new ‘position’ in“Against Method” (Feyerabend 1970), according towhich “Anything goes!” (Oberheim forthcoming).

Following Popper, Feyerabend began to develop a keen interest in thefoundations of quantum theory in this period. To this end, from 1949to 1952, he made annual trips to either Sweden or Denmark. As withWittgenstein, in August 1951, Feyerabend went to straight to thesource of the issues that interested him. He attended Bohr’ssummer seminar in Askov, on ‘the causality problem’(Collodel and Oberheim 2024, p. 14), where he witnessed an event thatsignificantly shaped his work in the foundations of quantum theory andhis complementary work in general methodology through his early work(until after his break with Popper’s school in December 1967):How Bohr and the Bohrians initially reacted to David Bohm’s“hidden variables” proposal. While Bohr was puzzled andsomewhat taken aback by this amazing news, after he left the room, theBohrians were dismissive of Bohm’s proposal, without goodgrounds (invoking von Neumann’s proof as a crutch). Bohm’ssubsequent attempts to develop a ‘hidden variables’interpretation of quantum theory in the face of von Neumann’salleged proof that no deterministic completion by‘hidden variables’ can be consistent with the principlesof quantum mechanics became a central focus of Feyerabend’s workin the foundations of quantum theory in the 1950s and 60s, asFeyerabend repeatedly criticized the Copenhagen interpretation anddeveloped his own Bohrian proposal for handling the measurementproblem.

Outside of physics, Feyerabend’s principal intellectualengagement in the late 1940s and early 1950s was in his capacity asstudent leader of the “Kraft Circle”, which was aphilosophy club centered around Kraft, that became part of theAustrian College Society (Kuby 2010). The Kraft Circle held regularmeetings from 1949 to 1952 (1978, p. 109), with the self-proscribedtask of “considering philosophical problems in a nonmetaphysicalmanner and with special reference to the findings of thesciences” (Feyerabend 1966a, pp. 1–2). Their main topic ofdiscussion concerned questions about the reality of theoreticalentities and the “external world”. As the student leaderof the Kraft circle, Feyerabend led the discussions, took notes, andinvited new participants. Bela Juhos, Walter Hollitscher, Georg Henrikvon Wright, and Elizabeth Anscombe were all visiting speakers.Elizabeth Anscombe had come to Vienna to improve her German totranslate Wittgenstein’s work:

She gave me manuscripts of Wittgenstein’s later writings anddiscussed them with me. The discussions extended over months andoccasionally proceeded from morning over lunch until late into theevening. They had a profound influence upon me though it is not at alleasy to specify particulars (1978, p. 114).

To everyone’s surprise, even Wittgenstein attended a meeting ofthis ‘third Vienna Circle’ (Stadler 2015) atFeyerabend’s invitation (Feyerabend 1995, pp. 74–76).Feyerabend went to Wittgenstein’s family home in Vienna toinvite him in person, but he was turned away. At the suggestion ofAnscombe (who admonished him against appearing sycophantic),Feyerabend then succinctly invited Wittgenstein to come to a meetingwith a short note: “We are discussing basic statements, and weare stuck”. Apparently, Wittgenstein could not pass up theopportunity to criticize Popper’s views. After arrivingbelatedly (over an hour late), taking a seat, and listening toFeyerabend (who was summarizing results of earlier discussions) for afew moments, Wittgenstein abruptly interrupted:“‘Halt, so geht das nicht’ (‘Stop,that’s not the way it is’)” and proceeded to discusswhat one sees through a microscope (Feyerabend 1995, p. 76).Feyerabend later reported that Wittgenstein seemed to prefer theirdisrespectful attitude to the fawning admiration he encounteredelsewhere. (1978, p. 109). And yet,

Not even a brief and quite interesting visit by Wittgenstein himself[…] could advance our discussion. Wittgenstein was veryimpressive in his way of presenting concrete cases, such as amoebasunder a microscope […] but when he left we still did not knowwhether or not there was an external world, or, if there was one, whatthe arguments were in favor of it (Feyerabend 1966a, p. 4).

Although Feyerabend had originally planned to submit a thesis onphysics, after getting nowhere with the electrodynamics problem he hadchosen, he turned to philosophy to earn his degree. He revised hisKraft circle discussion notes, which contained ideas and argumentsthat were roughly the right length, and turned them into his doctoralthesis, “Zur Theorie der Basissätze”, whichhe submitted in November 1951 under Kraft’s supervision, (p.115). Here, Feyerabend first delineated his peculiar views on meaningand method. He may even have realized that they did not comport toPopper’s notion of neutral ‘basic statements’ as theempirical basis of science as the invitation to Wittgenstein wouldseem to imply, although it would only be about a decade later thatFeyerabend openly criticized Popper’s empiricism in“Explanation, Reduction and Empiricism” (1962a).

In his 1951 Ph.D. thesis, Feyerabend first introduced his top-downview of the meaning of observation statements, according to which themeaning of any statement used to test a theory is determined by thetheory from which it is deduced and used to test, in contrast toCarnap’s dual language model, according to which observationlanguage gets it meaning from the observations, and is separate fromtheoretical language, which gets its meaning from observationlanguage. Feyerabend’s top-down account has the peculiarconsequence that one observation sentence makes two or moreincompatible statements depending on which theory is used to interpretit. For example, the sentence “the ball fell” meant thatit was pushed by its impetus before it meant that it was pulled bygravity. This Wittgensteinian insight laid the foundation forFeyerabend’s account of incommensurability, which he used tocriticize formal accounts of the growth of knowledge in“Explanation, Reduction and Empiricism” (1962a), arguingthat contemporary theories do not explain antiquated facts. It justappears that way because we continue to use the same observationsentences after scientific revolutions, when in fact, the samesentences can be used to make two incompatible statements–depending on which theory is used to interpret it, that is, from whichtheory it is deduced, together with auxiliary assumptions, and used totest. In this way, Feyerabend’s early philosophical work“started from and returned to the discussion of protocolstatements in the Vienna Circle” (Feyerabend 1991, p. 526).

3.3 Life at the London School of Economics (1952–1953)

In Feyerabend’s autobiography, we are told a little aboutPopper’s lectures and his famous LSE seminar. The lectures beganwith the claim that there is no method in science, but that thereare some simple and helpful rules of thumb. Popper tried toshow “how simple ideas that were derived from equally simplerequirements brought order into the complex world of research”(pp. 88–89). Having been convinced by Popper’s and PierreDuhem’s critiques of inductivism (the view that science proceedsthrough generalization from facts recorded in experience), Feyerabendconsidered falsificationism a real option, and, he says, he“fell for it” applying falsificationism in his papers andlectures (p. 89).

Later Feyerabend saw this phase of his development as an example ofthe dangers of abstract reasoning. Rationalism is already dangeroussince it “paralyzes our judgment” (p. 89) and is investedwith “an almost superhuman authority” (p. 90). But Popperadded a further dangerous element:simplicity. Such aphilosophy, complains Feyerabend, “may be out of touch withreality [… that is], with scientific practice” (p.90).

Feyerabend had adopted Popper’s normative approach toepistemology. In chapter II ofLogik der Forschung [TheLogic of Scientific Discovery] (1934, English 1959), Popperdistinguished between scientific practice and scientific standards,principles, or methodology. He argued against a“naturalistic” theory of method that makes standardsdepend on practice, opting instead for a strongly normativeepistemology, a discipline that lays down ideals and methodologicalrules for scientists to aspire to and ascribe to. This is one of themost important aspects of the Popperian perspective that Feyerabendinitially took on board. He was trying to contribute to a normative“model for the acquisition of knowledge” (see Preston1997, p. 13) until he broke with the Popperian school in December1967, reversing himself on realism in a ‘historicalturn’.

Such an epistemology, Feyerabend concluded, makes the false assumptionthat “rational” standards can lead to a practice that isas mobile, rich, and effective as the science we already have.However, science did not develop according to Popper’s model andfalsificationism does not promote scientific progress,but stifles it. It stifles progress by sharing a dogmatic featurewith school philosophies (the assumption of meaning invariance). Ifnew theoretical proposals have to predict the accepted observationstatements to justify replacing established theories, then scientificrevolutions that change the meaning of those statements would beimpossible to justify (Feyerabend 1962a). After his epiphany in 1967,Feyerabend generalized his criticism, arguing that while science isnot ‘irrational’, it contains no overarching‘rational’ pattern (as Otto Neurath had argued, p. 91).Rationalism (Popper’s included) could produce a science, but notthe progressive science we actually have.

In 1952, Feyerabend focused on two topics: the foundations of quantumtheory (von Neumann and Bohm) and Wittgenstein (p. 92).Feyerabend’s work on Wittgenstein from a Popperian perspectiveled to his views on meaning and method. He presented his ideas onscientific change to Popper’s LSE seminar and to a gathering ofillustrious Wittgensteinians (Elizabeth Anscombe, Peter Geach, H. L.A. Hart, and Georg Henrik von Wright) in Anscombe’s Oxford flat,which he then repeated in Popper’s LSE seminar. These meetingsseem to have been the first English presentations of his central ideathat some scientific theories are‘incommensurable’, although that term appeared inhis publications only a decade later (see Oberheim 2005):

On one occasion which I remember vividly Anscombe, by a series ofskilful questions, made me see how our conception (and even ourperceptions) of well-defined and apparently self-contained facts maydepend on circumstances not apparent in them. There are entities suchas physical objects which obey a “conservation principle”in the sense that they retain their identity through a variety ofmanifestations and even when they are not present at all while otherentities such as pains and after-images are “annihilated”with their disappearance. The conservation principles may change fromone developmental stage of the human organism to another and they maybe different for different languages (cf. Whorf’s “covertclassifications” […]). I conjectured that such principleswould play an important role in science, that they might change duringrevolutions and that deductive relations between pre-revolutionary andpost-revolutionary theories might be broken off as a result (1978, p.115).

Major discoveries, I said, are not like the discovery of America,where the general nature of the discovered object is already known.Rather, they are like recognizing that one has been dreaming (p.92).

These thoughts received an unenthusiastic reception from Hart, vonWright, and Popper (p. 92). Feyerabend scrutinized the manuscript thatbecame thePhilosophische Untersuchungen [PhilosophicalInvestigations], while visiting Anscombe in London: “Beingof a pedantic turn of mind”, he says, “I rewrote the bookso that it looked more like a treatise with a continuousargument” (1978, p. 116).

Anscombe translated Feyerabend’s critical reconstruction intoEnglish and sent it toThe Philosophical Review. This becameFeyerabend’s first English-language publication, which he calledhis “Wittgensteinian monster” (p. 115). He latercommented:

I knew that Wittgenstein did not want to present a theory (ofknowledge, or language), and I did not expressly formulate a theorymyself. But my arrangements made the text speak like a theory andfalsified Wittgenstein’s intentions (p. 93).

Wittgenstein’s emphasis on the need for concrete research andhis objections to abstract reasoning (“Look, don’tthink!”) somewhat clashed with my own inclinations and thepapers in which his influence is noticeable are therefore mixtures ofconcrete examples and sweeping principles (1978, p. 115).

In his review of thePhilosophical Investigations, hereconstructed Wittgenstein’s critique of a family of“realist” or “essentialist” theories ofmeaning according to which the meaning of a word is the objectdesignated or referred to by that word. Feyerabend argued thatWittgenstein was attempting areductio ad absurdum of realisttheories of meaning, showing that they had the untenable implicationthat we could not be said to know the meaning of words that wenevertheless constantly use in totally unproblematic ways. While hedefended Wittgenstein’s semantic views (adopting and developingthe implications of the contextual theory of meaning he read intoWittgenstein’s work), he harshly rejected Wittgenstein’sconception of philosophy as pure “philosophical analysis”of genuinely philosophical (pseudo-) problems. Feyerabend abhorredphilosophy thatmerely leaves everything as it is, relegatedtomerely letting flies out of bottles. Philosophy should beprogressive. It should contribute to improving our understanding andthe human condition, not to the dangerous entrenchment of the statusquo. At the same time, Feyerabend did not only endorseWittgenstein’s conception of genuinely philosophical (pseudo-)problems, he tried to specify their source, as well as to show howtheir clarification can lead to progress. They are caused byincompatible rules of usage implied by incommensurable, antiquatedscientific theories. Such problems are dissolved by reforming everydaylanguage according to our best theories.

In a short article published the next year (1956), Feyerabend expandedon his critique, arguing that consideration of G. E. Moore’sfamous “paradox of analysis” showed that“philosophy cannot be analytic and scientific, i.e.,interesting, progressive, about a certain subject matter, informativeat the same time” (“A Note on the Paradox ofAnalysis”, 1956a, p. 95). Feyerabend thenceforth plumped for(what he conceived of as)scientific philosophy. Like Popper,he increasingly adamantly rejected “analytic” philosophyor the “linguistic” philosophy which followed inWittgenstein’s wake, and with which Oxford University dominatedthe philosophical scene in the 1950s and early 1960s.

One of the things that comes across most clearly from hisautobiography is the consistently malleable nature ofFeyerabend’s views. He records that his friend Agassi caused himcompletely to change his mind about a book he considered translating.When Agassi urged Feyerabend to become a faithful Popperian,Feyerabend’s resistance seems to have been based mainly on hisaversion to groups more than his vague feeling that there was somekind of problem with Popper’s account.

3.4 Return to Vienna (1953–1955)

By the summer of 1953, when Popper had to apply for extra funds toallow Feyerabend to work as his assistant, Feyerabend had decided totake a leave from the Popperian church and return to Vienna. Althoughthe assistantship was soon approved, Feyerabend “felt quiteuncomfortable. I couldn’t put my finger on it; I only knew thatI wanted to remain in Vienna” (p. 99).

During this period Feyerabend translated Popper’s “wareffort”,The Open Society and its Enemies, wrotearticles on “Methodology” and “Philosophy ofNature” for a French encyclopedia, produced a report on post-wardevelopments in the Humanities in Austria for the U.S. Library ofCongress, and made a mess of his first professional opportunity as asinger (p. 98). But he also felt that he did not know what to do inthe long run, so he applied for jobs at various universities.

He met Arthur Pap, “who had come to Vienna to lecture onanalytic philosophy and who hoped, perhaps somewhat unrealistically,that he would be able to revive what was left from the great years ofthe Vienna Circle and the analytic tradition there” (1966a, p.3). Feyerabend became Pap’s assistant. Pap arranged for him tomeet Herbert Feigl in Vienna in 1954, and together they studiedFeigl’s papers. Feigl had been a member of the Vienna Circleuntil he emigrated to the USA in 1930, but he had never given up the“realist” view that there is a knowable external world. Heconvinced Feyerabend that the positivism of Kraft and Pap had notsolved the traditional problems of philosophy. His paper“Existential Hypotheses” (1950), together withKraft’s contributions and certain ideas Popper had put forwardat Alpbach in 1948 and 1949, greatly diminished Feyerabend’sdoubts about realism (1966a, p. 4). Here is how Feyerabend recountsFeigl’s influence:

It was […] quite a shock to hear Feigl expound fundamentaldifficulties and to hear him explain in perfectly simple languagewithout any recourse to formalism why the problem of application [ofthe probability-calculus] was still without a solution. Formalization,then, was not the last word in philosophical matters. There was stillroom for fundamental discussion-for speculation (dreaded word!); therewas still a possibility of overthrowing highly formalized systems withthe help of a little common sense! (1966a, p. 5).

4. Feyerabend’s Early Work: Liberalizing Empiricism

4.1 First Academic Appointment: The University of Bristol (1955–1958)

In 1955, with the help of references from Popper and ErwinSchrödinger, as well as his own big mouth (p. 102, 1978, p. 116),Feyerabend secured his first academic post lecturing in the philosophyof science at the University of Bristol, England. In his autobiography(pp. 103–4) he describes how Agassi had to help him prepare forthese lectures since they covered a subject Feyerabend claimed he hadnever studied (1978, p. 116). He also describes how for some time hefelt directionless and unsettled: he was “killingtime”.

In the summer of that year, he again visited Alpbach, where he met thephysicist and mathematician, Philipp Frank (another former member ofthe Vienna circle), who exerted on him a (somewhat delayed)influence:

Frank argued that the Aristotelian objections against Copernicusagreed with empiricism, while Galileo’s law of inertia did not.As in other cases, this remark lay dormant in my mind for years; thenit started festering. The Galileo chapters ofAgainst Methodare a late result (p. 103. See also 1978, p. 112).

At the turn of 1956, Feyerabend launched a weekly lecture course inBristol on the foundations of quantum mechanics, which he rememberedas being a disaster. Directly before the first meeting, he reversedhimself on indeterminism in the quantum theory, adoptingPopper’s view that it can be derived from (and so is nothingmore special than) classical indeterminacy (something Popper,throughout his work on the foundations of quantum theory tried, butultimately, failed to prove). Feyerabend excitedly published“Eine Bemerkung zum Neumannschen Beweis” [A Remark on vonNeumann’s Proof] (Feyerabend 1956b). Popper immediatelyprivately accused Feyerabend of plagiarism, insisting Feyerabend writeto the editors and have them add a note giving himself and Agassicredit for the ideas. Feyerabend initially agreed to write to theeditors and have them add such a note, but then he thought better ofit and told Popper that it was too late. By adopting Popper’sview on the foundations of quantum theory, however briefly, Feyerabend(it seemed to Popper), was getting way out ahead of his own“propensity interpretation”, which Popper only publiclylaunched at the Colston Research Society symposium in 1957 (throughFeyerabend, who read Popper’s paperin absentia). Inany case, it was a short-lived reversal for Feyerabend, who quicklyreturned to what he had been arguing before concerning vonNeumann’s proof. By January 1957, Feyerabend made his discomfortabout his published ‘Remark’ very clear in a letter toPopper: “if I am right your and Joske’s [Agassi] criticism[of von Neumann] which I have adopted myself [in Feyerabend 1956b] iswrong”. It now seemed to Feyerabend once again that “thereis much more behind [von Neumann’s] proof than you [Popper] wereinclined to admit” (Collodel and Oberheim eds. 2020, p.248).

In the summer of 1956, along with Alfred Landé, he chaired asuccessful seminar on philosophical issues in quantum mechanics atAlpbach. He also got married for the second time. This time to one ofhis former students, Mary O’Neill. But this relationship seemsto have been very short-lived, for he reports that his wife spentChristmas 1957 away from him with her parents, that she subsequentlyhad an affair, and that the last time he saw her was 1958.

In 1957, Feyerabend met David Bohm, triggering several related crucialevents that laid the foundations for Feyerabend’s philosophicaldevelopment to come. Bohm had been the favored protégéof Robert Oppenheimer and had contributed to the Manhattan Project inOak Ridge, Tennessee (his doctoral work on scattering had beenclassified), before he went to work with Albert Einstein (who becamehis new mentor), at Princeton in 1947. In 1951, Bohm fled fromMcCarthyism to South America (1951–55) and then Israel(1955–1957), before arriving in Bristol. Feyerabend studiedBohm’s dialectical conception of science and reality andBohm’s methodological views on the foundations of quantum theoryimmediately after Bohm’sCausality and Chance in ModernPhysics (1957) became available, on the eve of the ninthsymposium of the Colston Research Society in April, “Observationand Interpretation”, that Feyerabend had helped organize. At thesymposium, Feyerabend gave a paper “On the Quantum Theory ofMeasurement” that sets out his Bohrian strategy for handling themeasurement problem in the foundations of quantum theory, which hedeveloped in a series of papers criticizing the Copenhageninterpretation (not Bohr himself, who had proposed such an approach,as Feyerabend, to his chagrin, only found out at the conference)published in 1957, 1958, 1962, 1968, and 1969 (see Kuby 2021 and vanStrien 2020). Feyerabend also emphasized what was to become along-running central theme in his work: that there is no separate,neutral “observation language” or “everydaylanguage” against which the theoretical statements of scienceare tested, but that “the everyday level ispart of thetheoretical rather than something self-contained andindependent” (1981, p. 217, emphasis added). This viewrepresents a decisive break with Carnap and the logical positivistconception of theories. It led Feyerabend to the idea ofincommensurability, with which he eventually criticized Popper’sempiricism.

Moreover, during the discussions of the symposium, Feyerabendchampioned Bohm’s cause and his plea for more tolerance andpluralism in the foundation of quantum theory. Bohm and Vigier werecriticized for re-introducing untestable metaphysics into science sothat the quantum of action becomes derivative. However, Bohm andVigier saw nothing wrong with theirad hoc strategy, whichintroduces ‘hidden variables’ (a sub-quantum fluid, givingrise to quantum indeterminacy as a second, lower-level form ofBrownian motion) to explain the known results. After all, as theypointed out, the kinetic theory of heat wasad hoc and reliedon such hidden variables (in this case atoms) until it was empiricallycorroborated by Einstein’s prediction of the stochasticcharacter of Brownian motion, ending classical phenomenologicalthermodynamics and Energeticism. Perhaps another Einstein might comealong and do the same for their theory (think up an independent testcorroborating it). This is how Bohm’s defense of theadhoc strategy they were using to support his (and Vigier’s)1954 sub-quantum fluid proposal, as illustrated by Einstein’sprediction of the stochastic character of (classical) Brownian motion,became Feyerabend’s methodological argument for theoreticalpluralism as illustrated by the same example. Feyerabend’sargument based on this example became the centerpiece of his work inthe philosophy of science from “Explanation, Reduction andEmpiricism” (1962a) throughAgainst Method (1993).

When Feyerabend finally finished drafting a long-planned criticalstudy of Bohm’s 1957 bookCausality and Chance in ModernPhysics in 1959 (see Feyerabend 1960), he was still very muchunder Popper’s influence. The essay review is a detailedcritical comparison of Bohm’s methodology (‘thequalitative infinity of nature’) with Popper’sfalsificationism, with Feyerabend bluntly concluding: “I cannotaccept Bohm’s methodology of caution […] I prefer[…] the methodology of falsification as it has been developedby Popper” (1960, p. 339), while definitively rejecting“the epistemology behind Bohm’s belief that every theory,however absurd it may seem at first sight, has some kind of truth init and correctly mirrors what exists in the universe” (1960, p.337).

However, Bohm’s (unpublished) response to Feyerabend’scriticism of falsificationism motivated Feyerabend’s criticismof Popper’s empiricism in “Explanation, Reduction andEmpiricism” (1962a). In this collage of his earlierpublications, Feyerabend built on his peculiar ideas on meaning andmethod by adopting and developing Bohm’s argument for pluralismand Bohm’s plea for more tolerance towards his views based onthe Brownian motion example. He used them to criticize Popper’sempiricism while illustrating how there can still be a crucialexperiment between incommensurable alternatives despite the lack offormal relation between their corresponding predictions required for afalsification. Bohm increasingly became a central figure inFeyerabend’s formative development, leading him away fromPopper’s empiricism, towards Bohm’s dialectical views onscientific progress and the qualitative infinity of nature, such asontological pluralism and the non-autonomy of facts. In the long run,with the publication of his collected papers in 1981, Feyerabendretracted his Popperian criticism of Bohm’s views. Bohm andFeyerabend’s ideas continued to converge, including their sharedinterests in “fringe” science, as Bohm’s dialecticalideas continued to have visible effects on Feyerabend’spublished productions (see Feyerabend 1966b; Collodel and Oberheim2024). Most notably, Feyerabend increasingly openly flirts with aHegelian ontology, according to which reality is co-constituted bysubject-sided and object-sided moments — as can be seen bycomparing Bohm’s view on the qualitative infinity of nature withFeyerabend’s ‘Kant-on-wheels’ ontology (see Oberheim2016) which remains intact from “Explanation, Reduction andEmpiricism” (1962a) toTheConquest ofAbundance (1999).

In the summer of 1957, Feyerabend accepted an invitation to visitFeigl’s Minnesota Center for the Philosophy of Science inMinneapolis. The Center was, as Feyerabend later said, “one ofthe foremost institutions in the field” (p. 115). There he metCarl Hempel, Ernest Nagel, Hilary Putnam, Adolf Grünbaum, GroverMaxwell, E. L. Hill, Paul Meehl, and others. He returned to the Centerin 1958, having accepted another invitation to work there, backed byan NSF grant. He often returned in subsequent years, as Feiglcontinued to promote Feyerabend’s career and his engagement withthe leading philosophers of science in North America.

4.2 The University of California at Berkeley: Early Years (1958–1964)

In 1958, Feyerabend accepted an invitation to spend a year at theUniversity of California at Berkeley, after which the Universityadministration decided to give him tenure based on his publicationsand, of course, his big mouth (p. 115). After his repeated visits toMinnesota Center, he started lecturing full-time at Berkeley in 1960,where in the autumn of that year, he met Thomas Kuhn. They quicklybecame close compatriots, and Kuhn gave Feyerabend a draft ofTheStructure of Scientific Revolutions (1962). They were soon tobecome very closely associated, often recognized together for havingindependently introduced the idea of incommensurability intodiscussions of scientific progress in 1962 publications. They are alsooften lumped together as having initiated the movement away from alogic-oriented, to a historically oriented, approach to the philosophyof science, as well as among the “worst enemies ofscience” (together with Popper, see Lamb, Munevar, and Prestoneds. 2000) because they all reject the claim that theories can beproven to be true, opening the door to relativism. For these reasons,it can be surprising to learn that after their brief initial robustpersonal engagement that ended in the fall of 1961, direct discussionof the deep affinities in their ideas was set back by a rift in theirrelations that lasted about two decades (until 1983, seeCollodel and Oberheim 2024). At the time, Feyerabend was deeplyimmersed in normative epistemology. He wrote a series of scathingletters criticizing Kuhn’s historical approach, even accusingKuhn of intentionally misleading his readers. He acerbically attackedKuhn’s defense of ‘normal science’ as a perniciousform of dogmatism, and vehemently challenged Kuhn’s use ofpurportedly neutral historical facts given the normative implicationsof his account. For Feyerabend: “What you [Kuhn] are writing isnot just history. It is ideology covered up as history”(Collodel and Oberheim eds. 2024, p. 232) Feyerabend’spersistent, caustic criticisms of Kuhn and his work, especially therecurrent accusation that he was promoting a dogmatic, conservativeideology, led to a break in personal contact that lasted about twodecades – until their gradual rapprochement beginning in 1983.Thus, while Kuhn and Feyerabend were perceived to be ushering in thehistorical turn together over the next two decades, actually they hadbroken off personal contact when Kuhn left Berkeley at the end of1961, fueled by Feyerabend’s harsh criticism of Kuhn’shistorical approach and what became Kuhn’s most prominent work(see Collodel and Oberheim 2024. For the full survivingFeyerabend-Kuhn correspondence, see Collodel and Oberheim eds. 2024).According to Feyerabend’s normative approach, there are noneutral facts. Epistemology should result from ethical decisions aboutthe kind of knowledge we want to have. Science and methodology arewhat we make them, and what we make of them. We should want to have aprogressive science because the alternative is dogmatic ideology,which is dangerous. After all, it can quickly devolve into intoleranceand ultimately violence. As the German saying paradoxically puts it:“Der Weg ist das Ziel” [the route is thedestination, implying the goal is to stay on the path] so as not tobecome entrenched as dogmatic ideology.

From 1958 through 1967, Feyerabend developed his normative approach toepistemology in a series of papers on problems of empiricism thatattempted to contribute to a positive model for the acquisition ofknowledge. In these papers, he unpacks the consequences ofhis views on meaning and method, while criticizing hiscontemporaries’ accounts. These strange ideas emerged from hisearlier engagement with the Vienna Circle’s protocol sentencedebate and appear in their initial form in his 1951 Ph.D. thesis. Theywere initially published in English as “An Attempt at aRealistic Interpretation of Experience” (1958), which primarilytargets logical positivism and Carnap’s dual language model.“Explanation, Reduction and Empiricism” (1962a) sets outhis mature early view by drawing together his work in analyticphilosophy, general methodology, and the foundations of quantumtheory. Feyerabend also adds new critical targets (Popper included)and proposes a new test model for comparing incommensurable theories,launching his oft-repeated methodological argument for theoreticalpluralism. Subsequent major papers written in the 1960s before hisreversal in December 1967 develop particular aspects, and furtherconsequences of, his early views, while responding to criticisms.“How to be a Good Empiricist” (1963a) is “A Plea forTolerance in Matters Epistemological” that stresses thenon-autonomy of facts (facts do not exist independently of theories).“Realism and Instrumentalism: Comments on the Logic of FactualSupport” (1964) goes deeper into the issue of realism as anideal and his normative argument for it. In 1965, Feyerabend tried toclarify his contentious views in “On the ‘Meaning’of Scientific Terms” and “Reply to Criticism: Comments onSmart, Sellars and Putnam”. His early views culminate in twopapers: “Problems of Empiricism” (1965), which is alengthy paper that sets out the “ever-expanding ocean ofalternatives” (pp. 224–225) account of progress and hisbelatedly published (written before his December 1967 reversal)“Linguistic Arguments and Scientific Method” (1969), whichemphasizes his view that common knowledge and everyday language shouldbe corrected by our current best scientific theories as part ofscientific progress – and not merely analyzed – whichpermeates his early work, until he reversed himself in December1967.

“An Attempt at a Realistic Interpretation of Experience”(1958) explains Feyerabend’s peculiar views on meaning andmethod. Feyerabend argues that good science should be an attempt at arealisticre-interpretation of experience. Our bestscientific theories should be used to correct common knowledge andeveryday language as part of progress. Specifically, he criticizes thelogical positivist conception of meaning and Carnap’s duallanguage model of theoretical systems, arguing that they haveconsequences “at variance with scientific method and reasonablephilosophy” (1981, p. 17). This launches his signaturetwo-pronged (descriptive and normative) argumentative strategy,according to which an account is historically inaccurate andnormatively undesirable because it would stifle progress. According toFeyerabend, positivist theories imply the “stabilitythesis”: Even major changes in theory (scientific revolutions)will not affect the meanings of terms in the observation language.Against this supposition, Feyerabend defended what he called“Thesis I”, the idea that

the interpretation of an observation-language is determined by thetheories which we use to explain what we observe, and it changes assoon as those theories change (1958, p. 31).

Thesis I reverses the flow of meaning from what positivismpresupposes. Instead of meaning seeping upwards from observationlanguage to theoretical language (as logical positivism andCarnap’s dual language model would have it), Feyerabend,following Wittgenstein’s remarks and Gestalt psychology, arguesthat meaning trickles down from theory to experience. Theories informexperience, not vice-versa. This view results from combining acontextual theory of meaning, according to which meaning is conferredon terms by the theory used to interpret them, with Popper’s“hypothetico-deductive model” of theory testing. For anobservation statement to be used to test a theory, it must be deducedfrom that theory, and so it must have the meaning conferred on it bythat theory. Therefore, when theories change, the meanings of theobservations used to test them change.

Feyerabend also argues that the idea that the interpretation ofobservation terms does not depend upon the status of our theoreticalknowledge has undesirable consequences for positivists. It impliesthat “every positivistic observation language is based upon ametaphysical ontology” (Philosophical Papers, Volume 1,p. 21). If observation language gets its meaning directly fromexperience, then the observation language becomes untestable. Incontrast, according to Feyerabend’s realism, “theinterpretation of a scientific theory depends upon nothing but thestate of affairs it describes” (Philosophical Papers, Volume1, p. 42). Unlike positivism, which conflicts with science bytaking experiences as given, unanalyzable building blocks, realismtreats experiences as analyzable, as the result of processes notimmediately accessible to observation, so that the observationsstatements that they prompt can and should be tested and improved.

In “Das Problem der Existenz theoretischerEntitäten” (1960) [On the Problem of the Existence ofTheoretical Entities] (for an English translation, see Feyerabend1999), Feyerabend concludes that there is no special problemconcerning the existence of theoretical entities, as all entities aretheoretical. If, as the contextual theory implies, the meanings ofobservation statements depend on the principles of the theories usedto explain them, inadequacies in these principles will be transmittedto the observation statements that they subtend, whence our beliefsabout what is observed may be in error so that even our experiencesthemselves can and should be criticized and improved as we improve ourconception of reality. Instead of passively accepting observationstatements as given, we should attempt to find and test thetheoretical principles implicit in them, which may lead to changes tothose principles. This is part of Feyerabend’s conception ofscientific philosophy (see “Physik und Ontologie”1954), as part of ontology (the study of the implications our theorieshave concerning the nature of reality), which is how metaphysicalspeculation can become testable.

In “Explanation, Reduction and Empiricism” (1962a),Feyerabend develops his view that revolutionary new theories areincommensurable with established views. They are logically disjoint(‘incommensurable’) due to meaning variance in thenon-logical terms used to state the rival theories, which results inmeaning variance in the observation statements used to test them.Feyerabend was trying to develop Wittgenstein’s insights intoobservation language within the context of Popper’s criticalrationalist philosophy in a critical synthesis that develops the bestfrom both while criticizing the worst in each. From Wittgenstein,Feyerabend develops a contextual theory of meaning according to whichour theories determine the meaning of observation statements;specifically the insight that one observation sentence makes twoincompatible statements depending on which theory is used to interpretit. For example, in the transition to classical mechanics, ‘Theball fell’ was used to test and corroborate competing theoriesof motion, but it was used to make two incompatible statements (thatit was pushed from within or pulled from outside). Feyerabendconcluded that revolutionary new theories do not explain establishedfacts. They replace them. For example, relativity theory does notexplain classical facts. It replaces them with relativistic facts andclassical facts should become antiquated.

Feyerabend also adds three new critical targets, mirroring the title(Hempel on explanation, Nagel on reduction, and then Popper onempiricism). Feyerabend criticizes Hempel’s account ofexplanation because it implies that to justify the replacement of anestablished explanation, the new explanation should explain everythingexplained by the established one, plus something more. However,according to Feyerabend, in revolutions, meaning variance rendersrival explanations logically disjoint, so the new explanation doesnot, and cannot, explain the same observation statements alreadyexplained. The new explanation may explain the same observationsentences, but it does so by reinterpreting theminto incompatible observationstatements. Progress hasbeen made without meeting Hempel’s criteria, which are tooconservative, because they would make the justification ofrevolutionary new explanations impossible, and so stifle progress.Feyerabend then criticizes Nagel’s account of inter-theoreticreduction for the same reason, coming to the same conclusion. Inrevolutions, meaning variance renders rival theories logicallydisjoint, so formal relations cannot be used to explain (by reduction)established theories as special cases (as Nagel suggests), sosuggesting that they should have to, to be satisfactory asreplacements, stifles progress. Finally, setting up the mainconclusion of the paper, Feyerabend criticizes his interpretation ofPopper’s empiricism (today known as‘falsificationism’) for the same reason, concluding thatPopper’s empiricism also shares the same undesirable featurewith dogmatic school philosophies as Hempel and Nagel’s accounts(1962a, pp. 30–31). It cannot take incommensurability intoaccount (Feyerabend 1962a, p. 93), because there can be no formallycomparable consequences (observational or otherwise) deduced fromincommensurable alternatives (Feyerabend 1962a, p. 94). The new theoryshould not have to successfully predict (by deduction) all of theexisting theories’ correct predictions plus more (Hempel’scriteria for a more comprehensive explanation), plus an observationstatement that formally contradicts one of the establishedtheories’ unsuccessful predictions (the falsifier). This is notwhat has happened in revolutionary advances (which result in meaningvariance), and these criteria are normatively undesirable because theyset an impossibly high bar for justifying revolutionary new proposals,inhibiting progress.

Feyerabend’s criticism of these three new main targets (he alsorepeats his usual criticism of Carnap, the Copenhagen interpretation,and mentions a few others) is used to support the main contention ofthe paper, which is that, more generally, a formal account ofreduction and explanation is impossible (because of meaning variancethat results in incommensurability). Revolutionary new theories do notexplain antiquated facts.

Feyerabend was developing Popper’s view that increasingtestability increases empirical content and promotes progress througha process of conjectures and refutations. Feyerabend argues thatPopper’s empiricism has only a limited validity. It is limitedto testing commensurable theories. While Newton’s theoryfalsified Kepler’s (commensurable) laws in this Popperianfashion, relativity theory does not falsify classical mechanicsbecause meaning variance renders them incommensurable, precluding theformal relation (consistency and inconsistency) between thecorresponding observation statements deduced from each theory neededfor a falsification. More generally, instead of Popper’sconjectures and refutations (which only works for comparingcommensurable theories within shared theoretical frameworks), inrevolutions, it is conjectures and novel theory-laden corroborations,as illustrated by the Brownian motion example. The example purportedlyshows that Brownian motion only indirectly refuted classicalphenomenological thermodynamics once it was successfully predicted(and thereby potentially explained) by the kinetic theory of heat. Thephenomenological theory was not refuted by predictions deduced from itthat logically contradict predictions deduced from the kinetic theorythat were corroborated. It was abandoned because the ontology itimplies is incompatible with the ontology implied by a bettercorroborated new theory. The conclusion that there is no absolute massbecause mass is relative to motion was justified by the corroborationof relativity theory, not by a falsification of classical mechanics.This test model became the basis for his methodological argument fortheoretical pluralism, which became the centerpiece of his work inphilosophy of science throughAgainst Method (1993). Theargument is that no matter how successful an established theory is,new theoretical proposals should always be welcome (and pluralismshould be the norm) because sometimes the fact that some observationsrefute an established view can only be established by developing anincommensurable alternative to the established view.

Feyerabend also explains Wittgenstein’s illusive‘grammar’ as the source of genuinely philosophicalproblems as the tension between the semantic principles implied bycontemporary views and the semantic principles implied by antiquatedscientific theories that continue to haunt everyday language becausewe continue to use many of the same terms and sentences after arevolution but with new, incompatible meanings. However, againstWittgenstein (and linguistic philosophy more generally), Feyerabendargues that dissolution through clarification of such problems isoften crucial to scientific advance and that common knowledge andeveryday language should be corrected according to our best theoriesto avoid stifling scientific advance. For example, the mind-bodyproblem may perhaps dissolve by progress in cognitive psychology thatresults in eliminative materialism (see Shaw 2021a).

Feyerabend also introduces what is sometimes called his Kant-on-wheelsontology (see Oberheim 2016):

scientific theories are ways of looking at the world; and theiradoption affects our general beliefs and expectations, and therebyalso our experiences and our conception of reality. We may even saythat what is regarded as ‘nature’ at a particular time isourown product in the sense that all the features ascribedto it have first been invented by us and then used for bringing orderinto our surroundings. As is well known, it was Kant who mostforcefully stated and investigated this all-pervasive character oftheoretical assumptions. However, Kant also thought that the verygenerality of such assumptions and their omnipresence would foreverprevent them from being refuted. As opposed to this, the second ideaimplicit in the position to be defended here demands that our theoriesbetestable and that they be abandoned as soon as [they fail]a test (1962a, p. 29),

so that science proceeds to “better and better theories”(p. 30). Feyerabend also develops his contrastive, historical accountsof empirical content and knowledge.

The use of a set of theories with the properties indicated above[mutually incompatible, but factually adequate (p. 50)] will alsoimprove our understanding of each of its members by making it veryclear what is denied by the theory that happens to be accepted in theend (p. 67).

Moreover,

Any attempt to reduce this class [of theories that are mutuallyincompatible, but factually adequate] to a single theory would resultin a decisive decrease of the empirical content of this remainingtheory and would therefore be undesirable from the point of view ofempiricism. The freedom granted by the indeterminateness of facts istherefore not only psychologically important […] it is alsoneeded for methodological reasons (p. 50).

Relativity theory is better understood in contrast to classicalmechanics, which become part of its empirical content (as part of theset of statements ruled out by it).

“How to be a Good Empiricist” (1963a) is supposed to be asimplified summary of his earlier work, especially “Explanation,Reduction and Empiricism” (1962a) and “Problems ofMicrophysics” (1962b). Feyerabend argues for pluralism and makesa plea for more tolerance in matters of epistemology, mirroring hisspecific call for more tolerance towards Bohm’s proposal and hiscriticism of the hegemony of the Copenhagen interpretation (notBohr’s view, which Feyerabend was following) in the foundationsof quantum theory. Feyerabend emphasizes the relative nature of facts(which Bohm also emphasizes) that results from his Kant-on-wheelsontology, according to which there are classical facts andrelativistic facts, depending on which theory is used to explain them.He claimed the most significant insight of his early philosophy is hisrejection of the ‘autonomy principle’, according to whichfacts exist and are available independently of whether or not oneconsiders alternatives to the theory to be tested (1963a).

In “Mental Events and the Brain” (1963b) and“Materialism and the Mind-Body Problem” (1963c),Feyerabend applied his ideas to the mind-body problem arguing that thedistinction between mental and physical results from principles thatderived from an incommensurable antiquated scientific theory. Theclash between those principles and contemporary physicalism results ina genuinely philosophical (pseudo-) problem in Wittgenstein’ssense: the mind-body problem. He sought to undermine the suppositionthat the mind cannot be a physical thing by promoting the possibilityof“eliminative materialism” illustrating howcommon knowledge and everyday language should be reformed to reflectthe current state of scientific knowledge. Feyerabend’s radical‘eliminative materialist’ proposal was taken up by RichardRorty and Paul and Patricia Churchland, becoming an importantlegacy.

In “Realism and Instrumentalism: Comments on the Logic ofFactual Support” (1964) Feyerabend applied his normativeapproach to the dispute about how best to interpret scientifictheories, arguing that the disagreement between realists andinstrumentalists is not a factual issue, but a matter of choice. Wecan choose to see theories either as descriptions of reality(scientific realism) or as instruments of prediction(instrumentalism), depending on what ideals of scientific knowledge weaspire to. Adherence to these competing ideals (high informativecontent on the one hand, and the certainty of our senses, on theother) is to be judged by their respective consequences. Stressingthat philosophical theories have not merely reflected science but havechanged it, Feyerabend argued further that theformof our knowledge can be altered to fit our ideals. So we canhave certainty and theories that merely summarize experienceif we wish. However, he urged that we should opt instead for theoriesthat go beyond experience and try to say something informative aboutreality itself because this is how science makes progress (bycompeting as the best realistic interpretation of experience). In thisrespect, he was following Popper’s lead, reconstruing empiricismas a doctrine about the most desirable form for our theories, ratherthan as a view about the sources of knowledge.

“Problems of Empiricism” (1965) is a long paper that drawsconsequences of Feyerabend‘s methodological views for the natureof scientific progress. He emphasizes that he has been trying to“eliminate whatever remainder of an empirical ‘core’may still be contained in Popper’s point of view” (p.153). He envisions scientific progress as an ever-expanding ocean ofalternatives (very much like Bohm), rejecting the standard view ofscientific progress as converging on, or better approximating, anideal point of view:

Knowledge so conceived is not a process that converges toward an idealview; it is an ever increasingocean of alternatives, each ofthem forcing the others into greater articulation, ail of themcontributing, via this process of competition, to the development ofour mental faculties (1965, pp. 224–225; 1981, p. 107).

From this perspective, the history of science becomes an inseparablepart of science itself.

4.3 The Impact of the ‘Student Revolution’: The Mid to Late Sixties

In Alpbach in 1964, Feyerabend and Feigl jointly directed a seminar onthe recent development of analytic philosophy. Feyerabend was stillvery much attached to scientific philosophy, and considered philosophyworthless unless it made a positive contribution to the growth ofknowledge (which, of course, meant science) as he continued hiscrusades to disinfect contemporary empiricism and to chastiselinguistic philosophy for entrenching meanings by merely analyzingthem, instead of trying to improve them. The mid-to-late 1960s becamea time of ferment in Western culture, and Feyerabend was in the thickof it. In Berkeley, naturally, he ran into the Free Speech Movement,and he encountered the “student revolution” there too, aswell as in London and Berlin. This fired his interest in politicalphilosophy, more especially in political questions about science. Ofhis post at Berkeley, he later said:

My function was to carry out the educational policies of the State ofCalifornia which means I had to teach people what a small group ofwhite intellectuals had decided was knowledge (1978, p. 118).

However, Feyerabend’s experience under these educationalpolicies was undoubtedly one of the defining periods of hisintellectual life, a time in which he became deeply suspicious ofthese intellectuals and “Western rationalism” as awhole:

In the years 1964ff. Mexicans, Blacks, Indians entered the universityas a result of new educational policies. There they sat, partlycurious, partly disdainful, partly simply confused hoping to get an“education”. What an opportunity for a prophet in searchof a following! What an opportunity, my rationalist friends told me,to contribute to the spreading of reason and the improvement ofmankind! I felt very differently. For it dawned on me that theintricate arguments and the wonderful stories I had so far told to mymore or less sophisticated audience might just be dreams, reflectionsof the conceit of a small group who had succeeded in enslavingeveryone else with their ideas. Who was I to tell these people whatand how to think? (1978, p. 118. See also 1995, p. 123).

At this time, Feyerabend gave two lecture series, one on generalphilosophy, and one on philosophy of science. He seems to have gotinto some trouble at Berkeley by running his seminar on unacceptablyloose lines, regularly canceling lectures, and failing to prepare forthe lectures he did give:

I often told the students to go home—the official notes wouldcontain everything they needed. As a result an audience of 300, 500,even 1,200 shrank to 50 or 30. I wasn’t happy about that; Iwould have preferred a larger audience, and yet I repeated my adviceuntil the administration intervened. Why did I do it? Was it because Idisliked the examination system, which blurred the line betweenthought and routine? Was it because I despised the idea that knowledgewas a skill that had to be acquired and stabilized by rigoroustraining? Or was it because I didn’t think much of my ownperformance? All these factors may have played a role (p. 122).

But although he sympathized with the original aims of the studentmovement, Feyerabend was unimpressed by their leaders, feeling thattheir ideas were as authoritarian as those they were trying toreplace. He reports having cut fewer lectures during the studentstrike than either before or afterward! Nevertheless, by holding hislectures off-campus during this campus war, Feyerabend antagonized theadministration that had hired him. Reports of him giving“A” grades to every student in his class, regardless oftheir production (or lack of it), abound. He had the impression thatsome of his colleagues, especially John Searle, wanted to have himfired and that they only gave up when they realized how much paperworkwould be involved (p. 126).

In Hamburg in 1965, a discussion on the foundations of quantum theorywith the physicist C.F. von Weizsäcker belatedly set doubts inFeyerabend’s mind about the value of his normative approach togeneral methodology:

Von Weizsäcker showed how quantum mechanics arose from concreteresearch while I complained, on general methodological grounds, thatimportant alternatives had been omitted. The arguments supporting mycomplaint were quite good… but it was suddenly clear to me thatimposed without regard to circumstances they were a hindrance ratherthan a help: a person trying to solve a problem whether in science orelsewheremust be given complete freedom and cannot berestricted by any demands, norms, however plausible they may seem tothe logician or the philosopher who has thought them out in theprivacy of his study. Norms and demands must be checked by research,not by appeal to theories of rationality. In a lengthy article, Iexplained how Bohr had used this philosophy and how it differs frommore abstract procedures. Thus Professor von Weizsäcker has primeresponsibility for my change to “anarchism”—thoughhe was not at all pleased when I told him so in 1977 (1978, p.117).

During the summer of 1966, Feyerabend lectured on church dogma atBerkeley: “Why church dogma? Because the development of churchdogma shares many features with the development of scientificthought” (pp. 137–138). He eventually turned thesethoughts into a paper on “Classical Empiricism”, publishedin 1970, in which he argued that empiricism shared certain problematicfeatures with Protestantism.

In London, lecturing at University College and the LSE, he met ImreLakatos. The two became great friends, corresponding with one anotherregularly and voluminously until Lakatos’ death. Feyerabendrecalls that Lakatos, whose office was across the corridor from theLSE lecture hall, used to intervene in his lectures when Feyerabendmade a point he disagreed with (p. 128, 1978, p. 13). For his part,listening from the hallway to Lakatos lecture his students onPopper’s methodology in mid-December 1967, Feyerabend had anepiphany and ‘awoke’ from his ‘dogmaticslumber’ – he no longer considered himself to be aPopperian. He flew home and immediately announced his break fromPopper’s school in two dramatic letters sent on the 17 ofDecember, one to Lakatos and one to John Watkins that explain how his1962 criticism of Popper’s empiricism had led to his new‘position’ (in ‘scare quotes’ because hisposition is that he has no position). He immediately generalized fromthe limited validity of falsificationism to “anythinggoes” (the limited validity of all methodological rules) and heannounced his plan to use the title “Against Method”,citing Susan Sontag’sAgainst Interpretation (1966). Inthis reversal on realism, together with his attempt to contribute to apositive model for the acquisition of knowledge, Feyerabend abandonedhis recommendation that common knowledge should be corrected accordingto science. Instead, he began to argue that common knowledge should beprotected from science. Decisions about ontological issues such asrealism should be guided by the pursuit of happiness, not in supportof some tyrannical truth.

Despite taking his academic duties and responsibilities decreasinglyseriously, and coming into conflict with his own university’sadministration as a result, Feyerabend had not yet fouled hissubstantial reputation as a serious philosopher of science. He reportsthat he received job offers from London, Berlin, Yale, and Auckland,that he was invited to become a fellow of All Souls College, Oxford,and that he corresponded with Friedrich von Hayek (whom he alreadyknew from the Alpbach seminars) about a job in Freiburg (p. 127). Heaccepted the posts in London, Berlin, and Yale. In 1968, he resignedfrom UC Berkeley and left for Minneapolis, but grew homesick, gotre-appointed, and returned to Berkeley almost immediately.

5. Feyerabend’s Later Work: Towards Relativism, but then Beyond It

5.1Against Method (1970–1975)

After stints in London, Berlin, and Yale (all of them runningalongside his post at UC Berkeley), Feyerabend took up a visitingprofessorship at the University of Auckland, New Zealand, and lecturedthere in 1972 and 1974 (pp. 134–5). He even considered settlingdown in New Zealand around that time (p. 153), although this hardlyseems compatible with his jet-setting lifestyle.

In 1970, he published a long article entitled “Against Method:Outline of an Anarchistic Theory of Knowledge” in which heattacked several prominent accounts of scientific methodology.Originally, it was planned as a debate to be entitledFor andAgainst Method, in which Lakatos would put forward the“rationalist” case that there was an identifiable set ofrules of scientific method that make all good science, good science,and Feyerabend would attack it. Lakatos’ unexpected death inFebruary 1974, which seems to have shocked Feyerabend deeply, put anend to his hope that Lakatos, who had backed out, would reconsider andcontribute to the project.

Later that year, Feyerabend found himself lecturing at the Universityof Sussex:

I have no idea why and how I went to the University of Sussex atBrighton […] what I do remember is that I taught two terms(1974/1975) and then resigned; twelve hours a week (one lecturecourse, the rest tutorials) was too much (p. 153).

A member of Feyerabend’s audience recalls things in rather moredetail:

Sussex University: the start of the Autumn Term, 1974. There was not aseat to be had in the biggest Arts lecture theatre on campus. Tautwith anticipation, we waited expectantly and impatiently for theadvertized event to begin. He was not on time—as usual. In factrumour had it that he would not be appearing at all that illness (orwas it just ennui? or perhaps a mistress?) had confined him to bed.But just as we began sadly to reconcile ourselves to the idea thatthere would be no performance that day at all, Paul Feyerabend burstthrough the door at the front of the packed hall. Rather pale, andsupporting himself on a short metal crutch, he walked with a limpacross to the blackboard. Removing his sweater he picked up the chalkand wrote down three questions one beneath the other: What’s sogreat about knowledge? What’s so great about science?What’s so great about truth? We were not going to bedisappointed after all!

During the following weeks of that term, and for the rest of his yearas a visiting lecturer, Feyerabend demolished virtually everytraditional academic boundary. He held no idea and no person sacred.With unprecedented energy and enthusiasm he discussed anything fromAristotle to the Azande. How does science differ from witchcraft? Doesit provide the only rational way of cognitively organizing ourexperience? What should we do if the pursuit of truth cripples ourintellects and stunts our individuality? Suddenly epistemology becamean exhilarating area of investigation.

Feyerabend created spaces in which people could breathe again. Hedemanded of philosophers that they be receptive to ideas from the mostdisparate and apparently far-flung domains, and insisted that only inthis way could they understand the processes whereby knowledge grows.His listeners were enthralled, and he held his huge audiences until,too ill and too exhausted to continue, he simply began repeatinghimself. But not before he had brought the house down by writing“Aristotle” in three-foot high letters on the blackboardand then writing “Popper” in tiny, virtually illegibleletters beneath it! (Krige 1980, pp. 106–107).

Given his poor health, Feyerabend tried many unorthodoxapproaches. He started seeing a healer who had beenrecommended to him. The treatment was successful, and thenceforthFeyerabend referred to his own case as an example of both the failuresof orthodox medicine and the largely unexplored possibilities of“alternative” or traditional remedies.

Instead of a joint book with Lakatos, Feyerabend put together histour de force, the book version ofAgainst Method(1975), which he sometimes conceived of as a letter to Lakatos (towhom the book is dedicated). A more accurate description, however, isthe one given in his autobiography:

AM is not a book, it is a collage. It contains descriptions,analyses, arguments that I had published, in almost the same words,ten, fifteen, even twenty years earlier […] I arranged them ina suitable order, added transitions, replaced moderate passages withmore outrageous ones, and called the result “anarchism”. Iloved to shock people (pp. 139, 142).

The book contained many of the ideas and arguments developed in hisearlier works, augmented with a case study on the transition fromgeocentric to heliocentric astronomy. But whereas he had previouslybeen trying to contribute to a positive model for the acquisition ofknowledge (a pluralistic methodology), he now argued against allgeneral methodological rules, having concluded that they all have onlylimited validity. General methodological principles do not guideactual research. Actual research determines the scientific method andwhatever works, works – sometimes citing Einstein’s claimthat a scientist “must appear to the systematic epistemologistas a type of unscrupulous opportunist” (Feyerabend 1975, p.11).

Feyerabend emphasized that older scientific theories, likeAristotle’s theory of motion, had powerful empirical andargumentative support, and stressed, correlatively, that the heroes ofthe scientific revolution, such as Galileo, were not as scrupulous asthey were sometimes represented to be. He portrayed Galileo as makingfull use of rhetoric, propaganda, and various epistemological tricksto support the heliocentric position. Feyerabend also sought furtherto downgrade the importance of empirical arguments by suggesting thataesthetic criteria, personal whims, and social factors have a far moredecisive role in the history of science than rationalist or empiricisthistoriography would indicate.

Against Method explicitly drew the “epistemologicalanarchist” conclusion that there are no useful and exceptionlessmethodological rules governing the progress of science or the growthof knowledge. The history of science is so complex that if we insiston a general methodology that will not inhibit progress the only“rule” it will contain will be the useless suggestion:“Anything goes”. In particular, logical empiricism andPopper’s critical rationalism would inhibit scientific progressby imposing overly restrictive conditions on the legitimacy of newtheories. The more sophisticated “methodology of scientificresearch programmes” developed by Lakatos either containsungrounded value judgments about what constitutes good science, or itis reasonable only because it is epistemological anarchism indisguise. The phenomenon of methodological incommensurability rendersthe standards that these “rationalists” use for comparingtheories inapplicable. The book thus (understandably) had Feyerabendbranded an “irrationalist”. At a time when Kuhn wasdownplaying the perceived “irrationalist” implications ofhis work, Feyerabend was perceived to be casting himself in the roleothers already saw as his for the taking. He rejectedpolitical anarchism. His political philosophy was a mixtureof liberalism and social democracy.

He later said:

One of my motives for writingAgainst Method was to freepeople from the tyranny of philosophical obfuscators and abstractconcepts such as “truth”, “reality”, or“objectivity”, which narrow people’s vision and waysof being in the world. Formulating what I thought were my own attitudeand convictions, I unfortunately ended up by introducing concepts ofsimilar rigidity, such as “democracy”,“tradition”, or “relative truth”. Now that Iam aware of it, I wonder how it happened. The urge to explainone’s own ideas, not simply, not in a story, but by means of a“systematic account”, is powerful indeed (pp.179–180).

5.2 The Political Consequences of Epistemological Anarchism:Science in a Free Society (1978)

The critical reaction toAgainst Method seems to have takenFeyerabend by surprise. He was shocked to be accused of beingaggressive and nasty, so he replied by accusing his accusers of thevery same thing. He felt it necessary to respond to most of thebook’s major reviews in print, and later assembled these repliesinto a section of his next book,Science in a Free Society(1978), entitled “Conversations with Illiterates”. Here heberated unfortunate reviewers for having misreadAgainstMethod, as well as for being constitutionally incapable ofdistinguishing between irony, playfulness, argument byreductio adabsurdum, and the (apparently rather few) things he had reallycommitted himself to inAM. The spectacle of Feyerabendleveling these accusations at others is not itself without irony. (Hiswidow reports that he did not want the book re-issued). In thecommotion surroundingAM, Feyerabend succumbed todepression:

now I was alone, sick with some unknown affliction; my private lifewas in a mess, and I was without a defense. I often wished I had neverwritten that fucking book (p. 147).

Feyerabend saw himself as having undermined the arguments forscience’s privileged position within culture, and much of hislater work was a critique of the position of science within Westernsocieties. Theresults of science don’t prove itsexcellence, since these results have often depended on the presence ofnon-scientific elements. Science only prevails over other forms ofknowledge because “the show has been rigged in its favour”(1978, p. 102), and other traditions, despite their achievements, havenever been given a chance. The truth, he suggests, is that:

science is much closer to myth than a scientific philosophy isprepared to admit. It is one of the many forms of thought that havebeen developed by man, and not necessarily the best. It isconspicuous, noisy, and impudent, but it is inherently superior onlyfor those who have already decided in favour of a certain ideology, orwho have accepted it without ever having examined its advantages andits limits (1975, p. 295).

The separation of church and state should therefore be supplemented bythe separation of science and state, for us to achieve the humanity weare capable of. Setting up the ideal of a free society as “asociety in which all traditions have equal rights and equal access tothe centers of power” (1978, p. 9), Feyerabend argues thatscience is a threat to democracy. To defend society against science weshould place science under democratic control and be intenselyskeptical about scientific “experts”, consulting them onlyif they are controlled democratically by juries of laypeople (onFeyerabend’s political philosophy, see Kidd 2016b).

5.3 Ten Wonderful Years: The Eighties in Berkeley and Zurich

Out of all Feyerabend’s many academic positions, perhaps the onehe enjoyed most was his tenure throughout the 1980s at theEidgenössische Technische Hochschule, Zurich. Feyerabendapplied for the post after his friend Eric Jantsch had told him thatthe Polytechnic was looking for a philosopher of science. Theselection process was, by Feyerabend’s account, very long andsomewhat involved (pp. 154ff.). Having recently left another post inKassel, he appears to have given up hopes of being hired by the Swiss,and so “decided to remain in Berkeley and stop movingabout” (p. 158). But, after several stages in thedecision-making procedure, he was finally given the job, and“ten wonderful years of half-Berkeley, half-Switzerland”(p. 158) turned out to be exactly what he had been looking for. AtZurich, he lectured on Plato’sTheaetetus andTimaeus, and then on Aristotle’sPhysics. Thetwo-hour seminars, many of which were organized by Christian Thomas(with whom Feyerabend was to edit anthologies) were run on the samelines as Berkeley: no set topic, but presentations by the participants(p. 160). Feyerabend later considered this to be the period in whichhe “got his intellectual act together” (p. 162), meaningthat he recovered from the critical reactions toAgainstMethod. However, this didn’t seem to have affected hisattitude towards his institutional responsibilities: in Zurich, herefused offers of an office, because no office meant no office hours,and therefore no waste of time (pp. 131, 158).

Many of the more important papers Feyerabend published during themid-1980s were collected together inFarewell to Reason(1987). The major message of this book is that recognizing some formsof relativism is part of the solution to the problems generated byconflicting beliefs and ways of life (for the various components ofFeyerabend’s relativism, see Kusch 2016). Feyerabend suggeststhat the contemporary intellectual scene in Western culture is by nomeans as fragmented and cacophonous as many intellectuals would haveus believe. The surface diversity belies a deeper uniformity, amonotony generated and sustained by the cultural and ideologicalimperialism that the West uses to beat its opponents into submission.Such uniformity, however, can be shown to be harmful even when judgedby the standards of those who impose it. Cultural diversity, whichalready exists in some societies, is a good thing, not least becauseit affords the best defense against totalitarian domination.

Feyerabend proposed supporting the idea of cultural diversity bothpositively, by producing considerations in its favor, and negatively“by criticizing philosophies that oppose it” (1987, p. 5).Contemporary philosophies of the latter type are said to rest on thenotions ofObjectivity andReason. He seeks toundermine the former notion by pointing out that confrontationsbetween cultures with strongly held opinions about what is objectivelytrue can go in different directions. The result of such confrontationmay be the persistence of the old views, fruitful and mutualinteraction, relativism, or argumentative evaluation.“Relativism” here means the decision to treat otherpeople’s form of life, and the beliefs it embodies, as“true-for-them”, while treating our own views as“true-for-us”. Feyerabend feels that this is anappropriate way toresolve such a confrontation.

Feyerabend complains that the ideas of reason and rationality are“ambiguous and never clearly explained” (1987, p. 10);they are deified hangovers from autocratic times that no longer haveany content, but whose “halo of excellence” (ibid.) clingsto them and lends them spurious respectability:

[R]ationalism has no identifiable content and reason no recognizableagenda over and above the principles of the party that happens to haveappropriated its name. All it does now is to lend class to the generaldrive towards monotony. It is time to disengage Reason from this driveand, as it has been thoroughly compromised by the association, to bidit farewell (1987, p. 13).

Relativism is the tool with which Feyerabend hopes to “underminethe very basis of Reason” (ibid.). But is it Reason with acapital “R”, the philosophers’ abstraction alone,that is to be renounced, or reason itself too? Feyerabend is on weakground when he claims that “Reason” is aphilosopher’s notion that has no content, for it is preciselythe philosopher whois willing to attach a specific contentto the formal notion of rationality (unlike the layperson, whosenotion of reason is closer to what Feyerabend calls the“material” conception, where to be rational is “toavoid certain views and to accept others” (1987, p. 10).

Relativism is a result of cultural confrontation, an “attempt tomake sense of the phenomenon of cultural variety” (1987, p. 19).Feyerabend is well aware that the term “relativism” itselfis understood in many different ways. At some points, he merelyendorses views that no one would deny, but which do not deserve to becalled relativist (such as the idea that people may profit fromstudying other points of view, no matter how strongly they hold theirown view (1987, p. 20). At others, he does manage to subscribe to agenuinely relativist view but fails to show why it must be accepted(for a detailed analysis of Feyerabend’s forms of relativism,see Kusch 2016).

It was only in 1988, on the 50th anniversary of Austria’sunification with Germany, that Feyerabend became interested in hispast (p. 1). The Feyerabends left California for life in Switzerlandand Italy in the fall of 1989 (p. 2). It was during this move thatFeyerabend re-discovered his mother’s suicide note (p. 9), whichmay have been one of the factors that spurred him to write hisautobiography (the Waldheim affair was another). Feyerabend lookedforward to his retirement, and he and Grazia decided to try to havechildren. He claimed to have forgotten the thirty-five years of hisacademic career almost as quickly as he had earlier forgotten hismilitary service (p. 168).

5.4 Feyerabend in the Nineties: “Potentially Every Culture is All Cultures” (1994)

In the early 1990s, Feyerabend truncated his Berkeley lecture into aseries of five lectures entitled ‘What is knowledge? What isscience?’. These were originally delivered to a generalaudience, but Feyerabend edited the lectures into a monograph, whichwas published asThe Tyranny of Science (2011). The mainthemes of the book are as follows. Scientists and philosopherssometimes present science as a unified worldview, a monolith (or amonster, depending on one’s preferences). It is not. Science isboth incomplete and quite strongly disunified. It does not speak witha single voice, therefore appeals to the abstraction‘Science’ are out of place. The ideology known asobjectivism, or scientific materialism, which takes science to be ourultimate measure of what exists, is therefore ungrounded. Itsdefenders, who portray themselves as the defenders of Reason, areoften the kind of intellectual imperialists whose attitudes and advicein the past led, or would have led, to the destruction of first-nationcommunities.

Other equally popular philosophical claims about science are alsoflawed. The idea that science is successful needs interrogation.Science does have some successes, but these can be detached from theideology that seems to support them. The idea that science starts fromfacts, and eschews theories until the facts are gathered, is a myth.The same can be said of the idea that science is value-free, and alsoof the idea that scientific results are relevant to our most urgentsocial problems.

One aspect of the disunity of science is that ‘scientists’should not mean merely theoreticians: science also (and essentially)features experimentalists. In their work, the importance of hands-onexperience, and of what Michael Polanyi called ‘tacitknowledge’, is most obvious. But in fact, these sorts ofexperiences and knowledge play an important role throughout thesciences, even in their most obviously theoretical parts. ThePlatonic-rationalist picture of science as pure thinking about thenature of reality is a distortion.

One of Feyerabend’s central complaints is that a particularabstract, theoretical, ‘objectivist’ kind of science,together with an associated kind of thinking about science, nowdominates our thinking, and thereby excludes more human modes ofthought. Scientism, the belief that science has the answer to allmeaningful questions, is also a main target (on Feyerabend andscientism, see Kidd 2021). Feyerabend’s typical strategy is totake some hallowed idea (e.g., that the success of science is due toobservation and experiment), and ask: how did it arise? Tracing itsancestry back to ancient Greek thinkers (usually Plato, Parmenides, orXenophanes), he assesses their arguments for it and finds thememinently resistible. His complaint is not that their arguments areinvalid, though—that would be already to take on aquasi-scientific mode of assessment. Instead, Feyerabend makes itclear that he prefers ‘stories’ (or even‘fairytales’) to arguments, and that rival stories are tobe assessed in terms of how interesting, appealing, or revealing theyare. The sorts of stories the ancient Greek tragedians told, beingmore obviously human, fare better on such measures than those of theancient Greek philosophers, so we should not assume that philosophersare our best guides in such matters.

Feyerabend continued his investigation of “The Rise of WesternRationalism”. He tried to show that Reason (with a capital“R”) and Science had displaced the binding principles ofprevious worldviewsnot as the result of having won anargument, but as the result of power-play. While the firstphilosophers (the pre-Socratic thinkers) had interesting views, theirattempt to replace, streamline, or rationalize the folk wisdom thatsurrounded them was eminently resistible. Their introduction of theappearance/reality dichotomy made nonsense of many of the thingspeople had previously known. Even nowadays, indigenous cultures andcounter-cultural practices provide alternatives to Reason and animperialistic Western science.

In most of his work afterAgainst Method, Feyerabendemphasized the “disunity of science”. Science, he insists,is a collage, not a system or a unified project. Not only does itinclude plenty of components derived from distinctly“non-scientific” disciplines, but these components areoften vital parts of the “progress” science has made(using whatever criterion of progress you prefer). Science is acollection of theories, practices, research traditions, and worldviewswhose range of applications is not well-determined and whose meritsvary to a great extent. All this can be summed up in his slogan:“Science is not one thing, it is many.”

Likewise, inConquest of Abundance, the supposed ontologicalcorrelate of science, “the world”, consists not only ofone kind of thing but of countless kinds of things, things whichcannot be “reduced” to one another. There is no goodreason to suppose that the world has a single, determinate nature.Rather we inquirers construct the world in the course of ourinquiries, and the plurality of our inquiries ensures that the worlditself has a deeply plural quality: the Homeric gods and themicrophysicist’s subatomic particles are simply different waysin which “Being” responds to (different kinds of) inquiry.How the world is “in-itself” is forever unknowable. Inthis respect, Feyerabend’s work can be thought of as alignedwith social constructivism.

Feyerabend also published a surprisingly large number of littlereviews and papers in the 1990s (although many of them are very short,with overlapping content). Several appeared in a new journal,Common Knowledge, in whose inauguration he had a hand, andwhich set out to integrate insights from all parts of the intellectuallandscape. Although these papers were on scattered subjects, there aresome strong themes running through them, several of which bearcomparison with what gets called “post-modernism” (seePreston 1998). Often, they have provocative titles, such as“Atoms and Consciousness” (1992a), “Nature as a Workof Art: A Fictitious Lecture Delivered to a Conference Trying toEstablish the Increasing Importance of Aesthetics for Our Age”(1992b), and “Potentially Every Culture is All Cultures”(1994). They take “Ethics as a Measure of ScientificTruth” (1992c).

6. Conclusion: Last Things

A remarkable feature of Feyerabend’s philosophical developmentis how directly connected it was to the tumultuous times through whichhe lived – from logical positivism to post-modernism. He wasoccupied with his autobiography right up until his death on February11th, 1994, at the Genolier Clinic, overlooking Lake Geneva. At theend of the book, he expressed the wish that what should remain of himwould be “not papers,not final declarations,but love” (p. 181). A third volume of hisPhilosophicalPapers appeared in 1999, as didThe Conquest ofAbundance, the final unfinished book he had also been working on.In 2009, his long-lost,Naturphilosphie was published (inEnglishThe Philosophy of Nature, 2016), which was written inthe early to mid-1970s as a companion toAgainst Method,followed by his 1992 Trentino lecture series that he had edited intobook form asThe Tyranny of Science in 2011. A fourth volumeof hisCollected Papers,Philosophy and Physics waspublished in 2016. The first volume of his collected correspondence,Feyerabend’s Formative Years (Feyerabend andPopper. Correspondence and Unpublished Papers), was published in2020. The second volume (Feyerabend on Logical Empiricism, Bohmand Kuhn) was published in 2024.

Feyerabend came to be seen as a leading cultural relativist, not justbecause he stressed that some theories and worldviews areincommensurable, but also because he defended a form of relativism inpolitics as well as in epistemology. From the mid-1970s to the firsthalf of the 1990s, his denunciations of Western imperialism, hiscritique of scientism, his defense of the pursuit of alternativemedicine, astrology, and voodoo, and his emphasis on environmentalissues made him a hero of anti-technological countercultures.

Different components and phases of Feyerabend’s work haveinfluenced very different groups of thinkers. His early scientificrealism, contextual theory of meaning, and the way he proposed todefend materialism were taken up by Paul and Patricia Churchland.Richard Rorty, for a time, also endorsed eliminative materialism.Feyerabend’s critique of reductionism has influencedphilosophers of science such as Cliff Hooker, Bas van Fraassen, andJohn Dupré, and his general point of view has been popularizedby Alan Chalmers’ well-known introduction to philosophy ofscienceWhat Is This Thing Called Science? (1978). Feyerabendhas also had considerable influence within sociology, where many ofwhat were once taken to be controversial views have becomecommonplace. While he has directly inspired books like D.L.Phillips’sAbandoning Method (1973), which attempts totranscend methodology, less directly, he has exerted enormousinfluence on a generation of sociologists of science through hisrelativism, social constructivism, and apparent irrationalism,according to which social history is a series of accidents, notsomething governed by laws or even teleological (directed at somepre-established goal). It is still far too early to say whether, andin what way, his philosophy will be remembered.

Bibliography

Primary Sources

Works by Paul Feyerabend

Books

• 1975,Against Method: Outline of an Anarchistic Theory ofKnowledge, London: New Left Books. Second revised and enlargededition 1988. Third revised and enlarged edition 1993.
• 1978,Science in a Free Society, New Left Books:London.
• 1981,Realism, Rationalism and Scientific Method:Philosophical Papers, Volume 1, Cambridge: Cambridge UniversityPress.
• 1981,Problems of Empiricism.Philosophical Papers,Volume 2, Cambridge: Cambridge University Press.
• 1984,Wissenschaft als Kunst [Science as AnArt], Frankfurt am Main: Suhrkamp Verlag.
• 1987,Farewell to Reason, London: New Left Books.
• 1991,Three Dialogues on Knowledge, Oxford: BasilBlackwell.
• 1995,Killing Time: The Autobiography of Paul Feyerabend,Chicago: University of Chicago Press.
• 1999,Conquest of Abundance: A Tale of Abstraction Versus theRichness of Being, B. Terpstra (ed.), Chicago: University ofChicago Press.
• 1999,Knowledge, Science and Relativism.Philosophical Papers, Volume 3, edited J. Preston (ed.),Cambridge: Cambridge University Press.
• 2009,Naturphilosophie, H. Heit & E. Oberheim (eds.),Frankfurt am Main: Suhrkamp Verlag, 2009. English Translation, 2016,ThePhilosophy of Nature, H. Heit & E. Oberheim(eds.), New Jersey: Wiley-Blackwell.
• 2011,The Tyranny of Science, E. Oberheim (ed.),Cambridge: Polity Press.
• 2016,Physics and Philosophy.Philosophical Papers,Volume 4, S. Gattei & J. Agassi (eds.), Cambridge: CambridgeUniversity Press.

Papers and Shorter Works

• Feyerabend, P., 1955, Review of Wittgenstein 1953,ThePhilosophical Review, 64: 449–483.
• –––, “A Note on the Paradox ofAnalysis”,Philosophical Studies, 7: 92–96.
• –––, “Eine Bemerkung zum NeumannschenBeweis”,Zeitschrift für Physik, 145:421–423.
• –––, 1957, “On the Quantum-Theory ofMeasurement”, inObservation and Interpretation: A Symposiumof Philosophers and Physicists, Proceedings of the Ninth Symposium ofthe Colston Research Society, S. Körner & M. Pryce(eds.), London: Butterworths Scientific Pub., pp. 121–130.
• –––, 1958, “An Attempt at a RealisticInterpretation of Experience”,Proceedings of theAristotelian Society, 58: 143–170.
• –––, 1960, “Professor Bohm’sPhilosophy of Nature”The British Journal for the Philosophyof Science, 10: 40, 321–338.
• –––, 1962a, “Explanation, Reduction andEmpiricism” inScientific Explanation, Space and Time,Minnesota Studies in the Philosophy of Science, Vol. III, H.Feigl and G. Maxwell (eds.), University of Minnesota Press:Minneapolis, pp. 28–97.
• –––, 1962b, “Problems ofMicrophysics”, in R. Colodny (ed.),Frontiers of Science andPhilosophy, Pittsburgh: The University of Pittsburgh Press, pp.189–283.
• –––, 1963a, “How to Be a Good Empiricist:A Plea for Tolerance in Matters Epistemological”, in B. Baumrin(ed.), Philosophy of Science: The Delaware Seminar, Vol. II, New York:Interscience Publishers, pp. 3–39.
• –––, 1963b, “Mental Events and theBrain”,The Journal of Philosophy, 60: 11,295–296.
• –––, 1963c, “Materialism and the Mind-BodyProblem”,The Review of Metaphysics, 17:49–66.
• –––, 1964, “Realism and Instrumentalism:Comments on the Logic of Factual Support”, in M. Bunge (ed.),The Critical Approach to Science and Philosophy: In Honor of KarlR. Popper, London: The Free Press of Glencoe, pp.280–308.
• –––, 1966a, “Herbert Feigl: A BiographicalSketch”, in P. Feyerabend & G. Maxwell (eds.),Mind,Matter, and Method: Essays in Philosophy and Science in Honor ofHerbert Feigl, Minneapolis: University of Minnesota Press, pp.3–13.
• –––, 1966b, “Dialectical Materialism andthe Quantum Theory”,Slavic Review, 25:414–417.
• –––, 1969, “Linguistic Arguments andScientific Method”,Telos, 3: 43–63.
• –––, 1970, “Against Method: Outline of anAnarchistic Theory of Knowledge”, in M. Radner & S. Winokur(eds.), 1970, pp. 17–130.
• –––, 1991, “Concluding UnphilosophicalConversation”, in G. Munévar (ed.),Beyond Reason:Essays on the Philosophy of Paul Feyerabend, Dordrecht: Kluwer,pp. 487–527.
• –––, 1992a, “Atoms andConsciousness”,Common Knowledge, 1: 28–32.
• –––, 1992b, “Nature as a Work of Art: AFictitious Lecture Delivered to a Conference Trying to Establish theIncreasing Importance of Aesthetics for Our Age”,CommonKnowledge, 1: 3–9.
• –––, 1992c, “Ethics as a Measure ofScientific Truth”, in W. R. Shea & A. Spadafora (eds.),From the Twilight of Probability: Ethics and Politics, Canton(MA): Science History Publications, pp. 106–114.
• –––, 1994, “Potentially Every Culture isAll Cultures”,Common Knowledge, 3: 16–22.

Audio and Video Recordings

Links to the audio recordings can be found atPKF Centennial 2024.

• –––,Paul Feyerabend: Stories fromPaulino’s Tapes (Private Recordings 1984–1993),edited by Grazia Borrini-Feyerabend and Klaus Sander, Köln:Supposé, 2001.
• –––,Lieber Himmel—was ist ein Mensch?Interview by Rüdiger Safranski – Rome 1993 (44min German).
• –––,Paul Feyerabend:Wissenschaftstheoretische Plaudiereien (Original Audio,1971–1992), edited by Klaus Sander, Köln:Supposé, 2000.
• –––,Interview by Renato Parascandolo—Rome, 15 May 1992 (58min).
• –––,Feyerabend on the Vienna Circle. Excerpt from an interview by Vittorio Hösle and Renato Parascandolo—Rome, 15 May 1992 (10min).
• –––, The Trento Lectures, Trento, 4–8 May1992 (Five ca. 120min lectures). Published, in adapted form, asThe Tyranny of Science, edited by Eric Oberheim, Cambridge:Polity, 2011.Lecture 1.Lecture 2.Lecture 3.Lecture 4.Lecture 5.
• –––, The Zurich Lectures, ETH Zurich, April-July1985 (Twelve ca. 45min lectures, German). Published, in adapted form,as Historische Wurzeln moderner Probleme: Vorlesung an der ETHZürich 1985, edited by Michael Hagner and Michael Hampe,Suhrkamp: Frankfurt am Main, 2023.
• –––, Wissenschaft als Kunst (Science as an Art).Feyerabend’s Inaugural Lecture at ETH Zurich, 18 June 1981(56min, German).
• –––, The Kassel Lectures, University of Kassel,7 June – 6 July 1977 (Seven ca. 90min lectures, German).
• –––, A Critique of Nagel and Carnap onScientific Explanation, Minnesota Center for Philosophy of Science, 28May 1966 (56min).
• –––,Feyerabend at the 1964 European Forum Alpbach. Clip from a documentary film on the EFA(2min, German).
• –––, Eigenart und Wandlungen physikalischerErkenntnis (Peculiarity and Change in Physical Knowledge),RIAS-Funkuniversität, Berlin, 5 and 29 April 1963 (27min,German), published 1965 by Physikalische Blätter.doi:10.1002/phbl.19650210501
• –––, Psyche and Soma. Discussion with HerbertFeigl and Paul Feyerabend, Minneapolis, 26 November 1962 (95min).

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