The American philosopher Rudolf Carnap (1891-1970) was the most prominent representative of the school of logical positivism, sometimes called logical empiricism.

Rudolf Carnap was born on May 18, 1891, in Ronsdorf, Germany. From 1910 to 1914 he studied philosophy and science at the universities of Jena and Freiburg. At Jena, Gottlob Frege, the pioneering mathematical logician, directed his thinking. Carnap served as an officer in the Germany army during World War I, later resuming his studies at Jena, where he received his doctorate in 1921. As a student, Carnap came under the influence of Bertrand Russell and his writings on logic and epistemology.

In 1923 Carnap met Hans Reichenbach, with whom he later founded and edited Erkenntnis (1930-1940), the journal of the logical empiricists. Through Reichenbach he met Moritz Schlick, head of the Philosophical Circle at the University of Vienna. In 1926 Carnap became instructor of philosophy there and participated in the Circle. Ludwig Wittgenstein...