The Vienna Circle was a group of philosophers and other thinkers who met on a regular basis, discussing and publishing, in the city of Vienna during the 1920s and 1930s. While Vienna was the location of the earliest and most influential developments within this movement, Berlin and other cities were also important locations for the development of Logical Empiricism.
Movements are by nature ambiguous at their boundaries, and Logical Positivism is no exception. It is impossible to identify precise starting and ending points in time for this movement. It is not always clear which philosophers were part of the movement, and which ones were merely similar to, or associated with, the movement. Despite this vagueness, and despite the fact that movements are always constructs and not specific data points, it is nonetheless meaningful and useful to speak of Logical Positivism.
What is Logical Positivism? A definition or description of the movement would include these points: It is heavily empirical; it is anti-metaphysical; it takes physics and mathematics as paradigmatic for knowledge; it seeks to clarify philosophical questions by analysis of the words and propositions used to formulate those questions; its understanding of language is encapsulated in the slogan “The meaning of a word or sentence is the method of its verification.”
Each point in that definition requires considerable expansion.
Writing in 1969, Herbert Feigl explains:
Logical positivism began to form a fairly definite outlook in philosophy about forty years ago. As is well known, it was primarily the influence of Ludwig Wittgenstein and Rudolf Carnap that initiated the early phase of this — then new and radical — departure from the traditional ways of philosophizing. To be sure, some aspects of logical positivism are derived historically from Hume and Comte; but, in contrast, especially to Mill’s positivism, a new conception of logic (having its origins in Leibniz, Frege, and Russell) was united with the empiricism of Hume, Mach, and the early Einstein.
When Logical Positivism is described as heavily empirical, it means that the movement took observation to be the foundation of most knowledge.
As an anti-metaphysical movement, it considered words and sentences which refer to nonobservable things to be not wrong, but nonsensical. Thus the movement would consider a discussion of the mind, as separate from the brain, to be nonsense.
Because it takes physics and mathematics as paradigmatic for knowledge, it tends to favor what is quantifiable and measurable in observation. It looks to mathematics, and mathematical logic, to provide a framework in which observations can be organized.
The group sought to resolve philosophical paradoxes — longstanding questions, riddles, mysteries — by analyzing the words and sentences which formulated them. The Logical Positivists thought that many problems which had puzzled philosophers for years were the result of poorly-phrased propositions.
The method by which the Logical Positivists hoped to clear up philosophical misunderstandings — or what they took to be misunderstandings — was called “verificationism.” This method looked at a sentence — a proposition — and asked: by which procedure would it be determined whether this sentence is true or false? If such a method were found, then the Logical Positivists asserted that the method is the meaning: The meaning of a sentence is the method of its verification.
Herbert Feigl was a member of the Vienna Circle, and recalls:
The Vienna Circle consisted mainly of scientifically trained philosophers and philosophically interested mathematicians and scientists. Most of the members were tough-minded thinkers, Weltzugewandt (as Hans Hahn put it), ‘this-worldly’ rather than ‘other-worldly.’ They were radically opposed to metaphysical speculation, especially of the a priori and transcendent types. Since the development of the Vienna Circle is by now a familiar chapter in the history of recent philosophy, I propose, after dealing with some of the antimetaphysical doctrines of logical positivism, to concentrate on some of the aspects that are not as well known. I shall refer particularly to the work of Moritz Schlick, the founder and leader of the Vienna Circle. Schlick’s early work anticipated a good deal of what in more precise formulations was later developed by Carnap, Reichenbach, and others. In his Allgemeine Erkenntnislehre (first edition, 1918; second edition, 1925) there were also anticipations of some of the central tenets of Wittgenstein’s Tractatus Logico-Philosophicus. I think it was Schlick’s extremely unassuming character, his great modesty and kindliness, and his deep personal devotion to Wittgenstein that made him forget or suppress the great extent to which his views, independently developed and quite differently stated, already contained very important arguments and conclusions regarding the nature of logical and analytic validity; the semantic explication of the concept of truth; the difference between pure experience (Erleben), acquaintance (Kennen), and genuine knowledge (Erkennen), etc. Indeed, so deeply impressed was Schlick with Wittgenstein’s genius that he attributed to him profound philosophical insights which he had formulated much more lucidly long before he succumbed to Wittgenstein’s almost hypnotic spell.
The methods and assertions of Logical Positivism arose, in part, as reactions against some overly metaphysical trends among other groups of philosophers, like the British Idealists and other neo-Hegelian and post-Hegelian schools of thought. Logical Positivism may have served as a corrective and as a challenge to such idealism.
While there was value in not letting idealism go uninspected, it is also the case that, after the movement’s heyday in the late 1930s, there are few self-proclaimed Logical Positivists among the philosophers of the early twenty-first century.
