Logical Positivism

Logical positivism (also known as logical empiricism, scientific philosophy, and neo-positivism) is a philosophy that combines empiricism—the idea that observational evidence is indispensable for knowledge—with a version of rationalism incorporating mathematical and logico-linguistic constructs and deductions of epistemology. It may be considered as a type of analytic philosophy.

Logical positivism, in the formal sense, began from discussions of a group known as the First Vienna Circle which gathered during the earliest years of the 20th century in Vienna at the Café Central. After World War I, Hans Hahn, a member of that early group, helped bring Moritz Schlick to Vienna. Schlick's Vienna Circle, along with Hans Reichenbach's Berlin Circle, propagated the new doctrines more widely during the 1920s and early 1930s. It was Otto Neurath's advocacy that made the movement self-conscious and more widely known. A 1929 pamphlet written by Neurath, Hahn, and Rudolf Carnap summarized the doctrines of the Vienna Circle at that time. The doctrines included the opposition to all metaphysics, especially ontology and synthetic a priori propositions; the rejection of metaphysics not as wrong but as having no meaning; a criterion of meaning based on Ludwig Wittgenstein's early work; the idea that all knowledge should be codifiable by a single standard language of science; and above all the project of rational reconstruction, in which ordinary-language concepts were gradually to be replaced by more precise equivalents in that standard language.

During the early 1930s, the Vienna Circle dispersed, mainly because of political upheaval and the deaths of Hahn and Schlick. The most prominent proponents of logical positivism emigrated to the United Kingdom and the United States, where they influenced American philosophy considerably. Until the 1950s, logical positivism was the leading school in the philosophy of science. Ultimately, it failed to solve many of the problems with which it was centrally concerned, and after the Second World War, its doctrines increasingly came under attack by thinkers such as Nelson Goodman, Willard Van Orman Quine, J. L. Austin, Peter Strawson, Hilary Putnam, and Richard Rorty.