Skip to main content

Karl Popper

Logical Positivism

By Karl Popper, logical positivism, Moritz Schlick, Rudolf Carnap, Vienna Circle, Wittgenstein

Moritz Schlick

The phenomenon known as logical positivism (or logical empiricism) originated in the Vienna Circle, a 1920s group of thinkers led by the German philosopher (and physicist) Moritz Schlick (1882-1936). Other prominent members were Rudolf Carnap, Herbert Feigl, Otto Neurath, Philipp Frank, and Friedrich Waismann. The Circle met regularly at the University of Vienna, during the period 1924-36.
Herbert Feigl  (1902-89) was an Austrian. “Like most analytic philosophers, Feigl thought philosophical problems were reducible to problems of language” (information). Reductionism is not always advisable. Neurath (1882-1945) was a Hungarian political economist with another confining agenda.  “He denied any value to philosophy over and above the pursuit of work on science, within science and for science” However, “his views on the language, method and unity of science were led throughout by his interest in the social life of individuals and their well-being” (Jordi Cat, Stanford Encyclopedia of Philosophy).
The ultimate origins of the Vienna  Circle were a little earlier, from about 1908 onwards, when the philosophy of science was debated by mathematician Hans Hahn, Otto Neurath, and physicist Philipp Frank. These men favoured the positivism of the Austrian physicist Ernst Mach (d.1916).

In addition to the Vienna Circle, there was a similar gathering in Germany known as the Berlin Circle, inspired by Hans Reichenbach. However, the Vienna Circle gained more fame, assisted by the publication in 1929  of a German pamphlet often known as the Vienna Circle manifesto. The English translation of the pamphlet title is The Scientific Conception of the World: The Vienna Circle.

This document amounted to a summary of the formulations favoured, including a reliance upon empiricism or “knowledge gained by experience.” There was strong opposition to metaphysics and the doctrine of synthetic a priori truths associated with Immanuel Kant. The contention here is that a uniform scientific language should be the medium for all knowledge. The manifesto defers to the Tractatus of Wittgenstein, a book originally published in German as Logisch-philosophische Abhandlung (1921). 

The contribution of Wittgenstein was here problematic. The logical positivists favoured his critique of language; ironically, some of them are said to have disliked the Tractatus, deeming that work to be metaphysical. On his own part, Wittgenstein transpired to be in reaction to logical positivism in his later career.

In 1924, Schlick contacted Wittgenstein, who eventually agreed to meet him (and Waismann) to discuss the Tractatus. However, Wittgenstein subsequently concluded that the Vienna Circle were not representing his ideas correctly (Stadler 2015:219ff). He refused to attend further meetings, although he maintained a correspondence with Schlick.

The logical analysis, in favour with Schlick and his colleagues, deemed metaphysical statements to be meaningless. Such statements were said to be irreducible to statements about experience, i.e., not empirically verifiable. This meant that many traditional philosophical problems were rejected as fallacies resulting from mistakes in logical and verbal applications. However, other “problems” were awarded a reinterpretation as empirical statements, and thus deemed worthy of scientific investigation. The Vienna Circle validated statements in accord with their logical and mathematical code of “materialist” rationalism. They insisted upon a criterion of “verifiability” to determine the relevance of meaning.

A tragedy occurred when the Nazis gained power in Germany and Austria. Science could not compete with Fascism at this juncture. The Vienna Circle dispersed, a fair number of the members emigrating to America, where they became influential in universities. Schlick chose to stay in Austria, where he was murdered in 1936 by a fanatical student at the University of Vienna (Stadler 2015:597ff). The killer later became a member of the Austrian Nazi party.

Meanwhile, Friedrich Waismann (1896-1959) had extensive conversations with Wittgenstein, who influenced him to some extent. Nevertheless, Waismann came to believe that Wittgenstein had betrayed logical positivism with a diverging argument. Waismann became a lecturer at Oxford University. He is noted for his radical paper of 1956 entitled How I See Philosophy. In this article, Waismann arrived at the conclusion that philosophy is “very unlike science in that in philosophy there are no proofs, no theorems and no questions that can be decided.”

Philosophy cannot accurately be reduced to either science or language, despite many attempts of conceptualists in those directions. A question may be resolved in ways that are elusive of association with scientific procedure and not determined by modes of language.


Rudolf Carnap

The German philosopher Rudolf Carnap (1891-1970) was especially influential amongst the logical positivists. His early book Pseudoproblems in Philosophy (1928) maintained that many traditional “philosophical problems” were meaningless, being the result of faulty language. Carnap advocated the elimination of metaphysics from philosophical discourse, an emphasis which became a characteristic of his circle. He envisaged a new democratic and rational society enlightened by scientific knowledge (Carus 2007).

Carnap met Wittgenstein in the 1920s. In his autobiography, Carnap describes his encounter with the Tractatus author at Vienna: 

The impression he made on us was as if insight came to him as through a divine inspiration, so that we could not help feeling that any sober rational comment or analysis of it would be a profanation. Thus, there was a striking difference between Wittgenstein’s attitude to philosophical problems and that of Schlick and myself….Wittgenstein, on the other hand, tolerated no critical examination by others, once the insight had been gained by an act of inspiration. (David Auerbach, Carnap Meets Wittgenstein)

In The Logical Syntax of Language (1934), Carnap reformulated the concept of logical syntax proposed in the Tractatus. Carnap stressed philosophy as “the logic of the sciences,” which some critics say is too narrow a definition. His subsequent book Philosophy and Logical Syntax (1935) again rejected metaphysics, favouring the concept of verifiability in strict positivist idiom (see further Schilpp 1963).

Carnap emigrated to America, for many years being a Professor of Philosophy at the University of Chicago. “Since ordinary language is ambiguous, Carnap asserted the necessity of studying philosophical issues in artificial languages, which are governed by the rules of logic and mathematics” (see Mauro Murzi, “Rudolf Carnap,” Internet Encyclopedia of Philosophy).

After Wittgenstein, the second complication for logical positivism was the contribution of Karl Popper, who became famous as a critic of the positivists. His early work Logik der Forschung (1934) disputed the verifiability criterion, urging that this should be replaced by a criterion of falsifiability to compensate for excesses. This conflict has been much discussed; strong arguments are lodged against Popper’s tendency to diminish the importance of induction. However, Popper was nevertheless concerned to separate scientific from pseudoscientific statements, without insisting that metaphysical statements are necessarily meaningless.

In his autobiography, Popper says that he heard about the Vienna Circle in 1926 or 1927. He read the books of Carnap as these were published. “They [the Circle] were trying to find a criterion which made metaphysics meaningless nonsense, sheer gibberish, and any such criterion was bound to lead to trouble, since metaphysical ideas are often the forerunners of scientific ones” (Popper 1992:80). 

Popper preferred the guideline that “scientific theories always remain hypotheses or conjectures” (ibid:81). He furnished an illustration via the Einsteinian revolution in physics, which “had shown that not even the most successfully tested theory, such as Newton’s, should be regarded as more than a hypothesis, an approximation to the truth” (ibid).

In contrast, Carnap became noted for asserting that metaphysicists are like musicians with no musical ability. Metaphysics was here relegated to the status of an art, not a science, and one amounting to poetry.

Is the relegated art in all cases the same poetry? Are dogmatic theologians really demonstrating the same artistry as metaphysical philosophers like Plotinus and Spinoza, or a linguistic “contemplative” such as the aphoristic Wittgenstein? Certainly, the Tractatus was at the root of logical positivism; this ambiguous work  can be interpreted as an opposing factor to the format upon which it was grafted.

At the opposite extreme are those who deny all relevance to logical positivism, a significant minority movement of scientific intellectuals, attempting to negotiate Kantian and Hegelian arguments (positivists did not reject all the Kantian repertory by any means). Logical positivism was the ideological counter to Fascism, losing out to “ordinary language,” afterwards surviving in the intellectual language of analytical philosophy.


Ayer, Alfred J., Logical Positivism (Glencoe, Illinois: Free Press, 1959).

Carnap, Rudolf, The Logical Syntax of Language, trans. R. Smeaton (London: Kegan Paul, Trench Trubner, 1937).

Carus, A. W., Carnap and Twentieth Century Thought: Explication as Enlightenment (Cambridge University Press, 2007).

McGuinness, Brian, ed. and trans., Wittgenstein and the Vienna Circle: Conversations Recorded by Friedrich Waismann (Oxford: Blackwell, 1979).

Popper, Karl, Logik der Forschung (Vienna, 1935), trans. as The Logic of Scientific Discovery (London: Hutchinson, 1959).

——–Unended Quest: An Intellectual Autobiography (1974; new edn, London: Routledge, 1992).

Schilpp, Paul A., ed., The Philosophy of Rudolf Carnap (La Salle, Illinois: Open Court, 1963).

Stadler, Friedrich, The Vienna Circle: Studies in the Origins, Development, and Influence of Logical Empiricism (2001; new edn, Vienna: Springer, 2015).

Waissmann, Friedrich, Philosophical Papers, ed., B. McGuinness (Vienna: Springer, 1977).

Wittgenstein, Ludwig, Tractatus Logico-Philosophicus, trans. D. F. Pears and B. F. McGuinness (London: Routledge, 1961).


Kevin R. D. Shepherd
January 16th 2010 (modified 2021)

ENTRY no. 9

Copyright © 2021 Kevin R. D. Shepherd. All Rights Reserved.

J. L. Austin and the Oxford Tradition

By Alfred J. Ayer, Gilbert Ryle, J. L. Austin, Karl Popper

J. L. Austin

Apart from Wittgenstein, the major proponent of linguistic philosophy was John Langshaw Austin (1911-1960). Shortly after the death of Wittgenstein, Austin became the leading philosopher at Oxford University during the 1950s. He believed that analysis of the use of language is the basic concern of philosophy. One of his innovative concepts was “speech act,” denoting the factor of speech as behaviour. The title of his book How to Do Things with Words (1962) is a very graphic indicator of his format. His Philosophical Papers (1961) is also relevant.

Austin gained a classical scholarship at Balliol College. His linguistic training as a classicist apparently influenced his later career, in which his aim was to investigate and index commonly employed grammatical constructions.
One of his better known emphases was the speech act that he called “performative utterances,” such as promising, congratulating, or apologising. These he viewed as serving a purpose that does not imply any direct representation of reality. Those utterances can therefore never be true or false, only relatively successful or unsuccessful. Indeed, most other utterances were also not regarded by Austin as being truth-evaluable.

How words are used, in ordinary speech, is surely a relevant subject of enquiry. However, if that endeavour becomes totally dominant in philosophy, losses can offset the gains. There are counter-views to the linguistic paradigm.

The truth or falsity of utterances becomes pressing in the contemporary world. Ordinary speech of the 1950s was superior to the demise of diction fifty years later, facilitated by decadent media. Four letter words, and one letter words, are now the extent of literacy in some sectors. Even the BBC can now do with reminding, e.g., that the vogues for slang and abuse in common language are eroding the best descriptive English. For instance, the word you now too frequently becomes u. Conceptual density has proportionately attenuated. The contemporary mindface is too often one of falsity and superficiality.

Austin acknowledged the influence of G. E. Moore’s commonsense philosophy rather than Wittgenstein. However, the Oxford philosopher Alfred J. Ayer described Austin’s blanket linguistic approach as arid. Ayer had early formed an enthusiasm for logical positivism, associated with the Vienna Circle, which he visited as a guest. His book Language, Truth, and Logic (1936) was influential in the spread of logical positivism, an outlook succeeded by linguistic philosophy. Ayer was also a follower of Bertrand Russell, who expressed aversion to linguistic analysis after himself initiating that trend. Ayer’s respect for the Cambridge tradition was commemorated in his Russell and Moore: The Analytical Heritage (1971).

Sir Alfred Ayer was Wykeham Professor of Logic at Oxford from 1959 to 1978. He is sometimes identified as a partisan of David Hume (Ayer 1980). Here Ayer closely follows basic arguments of Hume, and in such a manner as to indicate his sense of empathy. Despite his popularity with a public readership, Ayer lost to Wittgenstein and Austin in the primacy of influence upon academic colleagues at Oxford and Cambridge. The reason for this has been critically suggested in terms of: “Ayer had remained faithful to Russell, if anything excessively so, but never had any original ideas” (Magee 1998:380). Cf. Graham Macdonald, “Alfred Jules Ayer,” Stanford Encyclopedia of Philosophy.

Ayer’s reputation for atheism is accompanied by his disclosure of a near death experience, which appears to have strongly impressed him. The relevant account is not typical of logical positivism. This experience did not alter Ayer’s atheistic outlook, but did evoke from him reflections, including the possibility that consciousness can continue after death.

Another Oxford luminary was Gilbert Ryle (1900-1976), author of a provocative work entitled The Concept of Mind (1949). That thesis of the “ghost in the machine” argued strongly against Cartesian and related concepts of the independent nature of mind from the body; in the Ryle format, mental processes are not at all distinct from bodily actions.

“It is not surprising that Gilbert Ryle’s ‘deliberate abusiveness’ towards ‘the dogma of the Ghost in the Machine’ should have been forecast by Ryle himself as being in line for the accusation of a behaviourist approach” (Shepherd 1991:129). 

Transiting from Husserl and Heidegger, Professor Ryle became “the John the Baptist of linguistic analysis” (Magee 1998:381). Professor Magee had the advantage of personal encounters with Ryle, so his comments cannot easily be dismissed. Ryle came under the influence of Wittgenstein, a factor “which continued even after Ryle came actively to dislike Wittgenstein” (ibid:382).

Furthermore, Ryle’s controversial book is described by the critical Oxonian in terms of “not only the central thesis but also what came to be the best known of the subsidiary theses come straight out of Schopenhauer, while all the time Ryle himself genuinely believed he was putting forward his own ideas” (ibid). Ryle is here said to have understood this factor of derivation after publication, and after being informed accordingly. Cf. Julia Tanney, “Gilbert Ryle” (2009), Stanford Encyclopedia of Philosophy, seeking “to raise the possibility that his [Ryle’s] work has been widely misunderstood.”

Ryle was eclipsed by the prominence of Austin, whose works were published posthumously. Ryle is said to have resented Austin as a consequence (Magee 1998:383). Events at Oxford included another ideological friction; Ryle is reported to have blocked the appearance of Karl Popper in an Oxford role of professorship (ibid:89). Sir Karl (who taught at London University) was apparently feared by some prestigious rival contemporaries for his critical talents, manifesting in various books now famous. Popper had a much closer association with the sciences than some of his rivals.

Bryan Magee (1930-2019) was a dissenter from the Oxford tradition. He expressed the controversial conclusion, in relation to the period under discussion, that “except for Popper’s their work [that of British analytical philosophers after Russell and Moore] constituted a bankrupt tradition” (Magee 1998:380). This is considered too strong a statement by some other academics. 


Austin, J. L., Philosophical Papers, eds., J. O. Urmson and G. J. Warnock (Oxford University Press, 1961; third edn, 1979).

——–Sense and Sensibilia, ed. G. J. Warnock (Oxford University Press, 1962).

——–How to Do Things with Words: The William James Lectures delivered at Harvard University in 1955 (1962; second edn, Harvard University Press, 1975).

Ayer, Alfred J., Hume (Oxford University Press, 1980).

Gustafsson, Martin, and Richard Sorli, eds., The Philosophy of J. L. Austin (Oxford University Press, 2011). 

Magee, Bryan, Confessions of a Philosopher (London: Phoenix, 1998).

Ryle, Gilbert, The Concept of Mind (London: Hutchinson, 1949).

Shepherd, Kevin R. D., Meaning in Anthropos (Cambridge: Anthropographia, 1991).

Kevin R. D. Shepherd
December 13th 2009 (slightly modified December 2018)

ENTRY no. 5

Copyright © 2018 Kevin R.D. Shepherd. All Rights Reserved.