logical positivism, also known as logical or scientific empiricism, modern school of philosophy that attempted to introduce the methodology and precision of mathematics and the natural sciences into the field of philosophy. The movement, which began in the early 20th cent., was the fountainhead of the modern trend that considers philosophy an analytical, rather than a speculative, inquiry. It began in the group called the Vienna Circle, which formed around Moritz Schlick when he occupied (1920s) a chair of philosophy at the Univ. of Vienna. Among its members were the philosophers Friedrich Waismann, Otto Neurath, Rudolf Carnap, Herbert Feigl, and Victor Kraft, and the mathematicians Hans Hahn, Carl Menger, and Kurt Gödel. The movement soon had a widespread following in Europe and the United States. Among those philosophers whose work was influenced by the Vienna Circle are A. J. Ayer and Gilbert Ryle. The position of the original logical positivists was a blend of the positivism of Ernst Mach with the logical concepts of Gottlob Frege and Bertrand Russell, but their inspiration was derived from the writings of Ludwig Wittgenstein, who lived for a time near Vienna, and G. E. Moore. The Vienna Circle in general subscribed to Wittgenstein's dictum in Tractatus Logico-Philosophicus that the object of philosophy was the logical clarification of thought; philosophy was not a theory but an activity. The logical positivists made a concerted effort to clarify the language of science by showing that the content of scientific theories could be reduced to truths of logic and mathematics coupled with propositions referring to sense experience. They held that metaphysical speculation was nonsensical, propositions of logic and mathematics tautological, and moral or value statements merely emotive. They championed the highly influential verification principle, from which it follows that a proposition has meaning only if some sense experience would suffice to determine its truth. The Vienna Circle disintegrated after the Nazis took control of Austria in the late 1930s. The influence of the movement, as a movement, ended c.1940. However, the concepts of the movement, particularly in its emphasis on the function of philosophy as the analysis of language, has been carried on throughout the West.
See A. J. Ayer, ed., Logical Positivism (1959, repr. 1966); E. Gellner, Words and Things (rev. ed. 1968, repr. 1979).