Karl Popper and the Social Sciences

THE VIENNA CIRCLE’S POSITIVISM

T H E VI ENNA CI RCLE’S POSI T IVISM To help assess Popper’s relation to positivism, I want to present a sketch of the key ideas that undergird the doctrine. Such an account is necessary because today the term positivism is often used loosely and often used as a term of abuse. For many critics of positivism, the doctrine means nothing more than the attempt to model the social sciences on the natural sciences or, even more broadly, any attempt to quantify social phenomena.1 Further, positivism is often—and wrongly—associated with political conservatism. In fact, nearly all of the key figures of twentieth-century positivism were leftists, and some—including Otto Neurath, Rudolf Carnap, and Moritz Schlick (who was killed by a Nazi student)—were socialists with Marxist leanings (Hacohen 2000, 186–195; Ayer 1959, 6–7). In order to understand Popper’s philosophy we will need to understand the positivism that he was reacting to and eventually claimed to have “killed”—namely, the logical positivism of the Vienna Circle (UQ, 88). Positivism, needless to say, has a long history. Following the hints of his teacher Saint-Simon, August Comte coined the term positivism, although the deeper roots of the doctrine can be traced to the British empiricists, such as Bacon, Locke, and Hume, in addition to its French sources. These thinkers emphasized the primary importance of sensory or empirical data in producing our knowledge of the world and expressed skepticism toward any assertion that could not be verified by empirical observation or demonstrated through logical or mathematical analysis. Leszek Kolakowski, in his history of positivism , described the essence of the doctrine as follows: Defined in the most general terms, positivism is a collection of prohibitions concerning human knowledge, intended to confine the name of “knowledge” (or “science”) to those operations that are observable in the evolution of the modern sciences of nature. More especially, throughout its history positivism has turned a polemical cutting edge to metaphysical speculation of every kind, and hence against all reflection that either cannot found its conclusions on empirical data or formulates its judgments in such a way that they can never be contradicted by empirical data. (Kolakowski 1968, 9) The central importance of sensory data and the skepticism toward metaphysics remained the key ideas animating the version of positivism developed in the 1920s and 1930s by the Vienna Circle, which included such thinkers as Rudolf Carnap, Otto Neurath, Herbert Feigl, Carl Hempel, A. J. Ayer, and the young Ludwig Wittgenstein (Ayer 1959, 3–28; Hacking 1983, 41–57; Hacohen 2000, 41–57; Joergensen 1970; Kolakowski 1968, 174–206). It is the Vienna Circle’s account of scientific knowledge and explanation, usually referred to as “logical positivism” or sometimes “logical empiricism,” that philosophers of natural science generally have in mind when they speak of positivism (with or without a preceding adjective). As with any philosophical 24 KARL POPPER AND THE SOCIAL SCIENCES ...