WAISMANN, FRIEDRICH (1896–1959), Austrian philosopher. One of the original members of the Vienna Circle, he was born in Vienna. He was assistant of the German neopositivist philosopher Moritz Schlick at Vienna University (1929–36), and then lectured at Cambridge (1937–39). He then went to Oxford as reader in the philosophy of mathematics, and later as reader in the philosophy of science. Waismann's philosophy began as a rather orthodox version of logical positivism, but under the influence of Wittgenstein's later views changed radically, moving away from an emphasis upon formalism to a type of extreme informalism. His later work, such as the series of articles entitled "Analytic-Synthetic" (Analysis, 1949–53) and "Language Strata" (Logic and Language, 1953), attempts to relieve philosophical perplexity by contrasting the rigid caricatures of language use developed by traditional philosophers with the flexible, subtle, and fluid use of language in its everyday employment. The high point in this development is to be found in his paper "How I See Philosophy" in Contemporary British Philosophy (1956) where he contends that philosophy is "very unlike science in that in philosophy there are no proofs, no theorems and no questions that can be decided."
Apart from these influential papers, Waismann's main contributions are to be found in Einfuehrung in das mathematische Denken (1936; Introduction to Mathematical Thinking, 1951), and The Principles of Linguistic Philosophy. The latter work was unfinished at Waismann's death, and was edited by R. Harre and published in 1965.
S. Hampshire, Friedrich Waismann 1896 – 1959 (Eng., 1960); B.F. Mc-Guiness (ed.), Wittgenstein und der Wiener Kreis von Friedrich Waismann (1967).