Rudolf Carnap (kär´näp, –năp), 1891–1970, German-American philosopher. He taught philosophy at the Univ. of Vienna (1926–31) and at the German Univ. in Prague (1931–35). After going to the United States he taught at the Univ. of Chicago (1936–52) and at the Univ. of California at Los Angeles (1954–62). Carnap was one of the most influential of contemporary philosophers; he is known as a founder of logical positivism and made important contributions to logic, semantics, and the philosophy of science. In Logische Syntax der Sprache (1934; tr. The Logical Syntax of Language, 1937) he defined philosophy as
"the logic of the sciences"
and considered it a general language whose only legitimate concern could be to describe and criticize the language of the particular sciences. All propositions were held to be either tautological (embodying logical or mathematical systems), scientific (embodying philosophy properly understood), or nonsensical (embodying the nonverifiable propositions of traditional philosophy). Through an analysis of scientific, logical, and mathematical language he revealed the inadequacies of everyday speech. Carnap later modified this extreme view, which rejects almost all of traditional philosophy. His other works include Introduction to Semantics (1942), Meaning and Necessity (1947, 2d ed. 1956), Logical Foundations of Probability (1950), and Einführung in die symbolische Logik (1954; tr. Introduction to Symbolic Logic and its Applications, 1958).
See studies by P. A. Schilpp, ed. (1963, repr. 1984) and R. Butrick (1970).