CARNAP, Rudolf (1891-1970), prominent figure in the philosophical movement known as logical positivism or logical empiricism. Carnap was born on May 18, 1891, in Ronsdorf, Germany. Educated at the
universities of Jena and Freiburg, he specialized in mathematics, physics, and philosophy. He particularly acknowledged the influence of the German mathematician Gottlob Frege in mathematics and the British philosophers
Bertrand Russell and Ludwig Wittgenstein in philosophy. Carnap became a leading member of the Vienna Circle, a group of positivist scientists and philosophers. In 1935 he went to the U.S. to escape Nazism and joined the
faculty of the University of Chicago. In 1954 he accepted a positionat the University of California, Los Angeles. He died in Santa Monica, Calif., on Sept. 14, 1970. Carnap interpreted philosophy as logical analysis. He
was primarily concerned with the analysis of the language of science, because he judged the empirical statements of science to be the only factually meaningful ones. His early effort in The Logical Structure of the
World (1928; trans. 1967) to reduce all knowledge claims to the language of sense data, his developing preference for language that described behavior (physicalistic language), his work on the syntax of scientific
language in The Logical Syntax of Language(1934; trans. 1937), and his various treatments of the verifiability, testability, or confirmability of empirical statements are testimonies to his belief that the problems of
philosophy are reducible to the problems of language. Carnap's principle of tolerance, or the conventionality of language forms, emphasized freedom and variety in language construction. He was particularly interested in
the construction of formal, logical systems. He also did significant work in the area of probability, distinguishing between statistical and logical probability in his work Logical Foundations of Probability (1950).
Carnap helped found and edit the journal Erkenntnis and the International Encyclopedia of Unified Science.R.M.B.