Sense and veriﬁcationism: Logical positivism
In Chapters 1 and 2 we looked at some aspects of Frege’s attempt to systematise our intuitive notion of meaning, and how that attempt was modiﬁed in various ways by Russell. In this chapter we will look at another attempt: that carried out by the logical positivists. Logical positivism was a school of philosophy, centred in Vienna, which grew up in the 1920s and 1930s, and which was institutionalised in the “Vienna Circle”. The leading ﬁgure in the Circle was Moritz Schlick (1882-1936), and it counted among its supporters philosophers such as Neurath, Weissman, Feigl, Gödel, Ayer, Carnap, and Hahn. The main philosophical inﬂuences on the Circle stemmed from the Scottish empiricist David Hume (1711-1776), the Irish empiricist George Berkeley (1685-1753), and, less distantly, Frege and Russell. The inﬂuence of Frege and Russell on the logical positivists was largely transmitted through the Tractatus Logico-Philosophicus, the famous early work of Ludwig Wittgenstein (1889-1951) that was ﬁrst published in 1921.