Rudolf Carnap - Life, Logician, Philosophy, Selected publications

Philosopher, born in Wuppertal, W Germany. He studied at Freiburg and Jena, becoming lecturer at Vienna (1926–31), and professor of philosophy at Prague (1931–5), Chicago (1936–52), and California, Los Angeles (1954–70). He was one of the leaders of the ‘Vienna Circle’ of logical positivists. His writings include Der logische Aufbau der Welt (1928, The Logical Construction of the World), Logische Syntax der Sprache (1934, Logical Syntax of Language), and Meaning and Necessity (1947), as well as semantic studies of induction and probability.

Western Philosophy 20th-century philosophy
Rudolf Carnap
Name:	Rudolf Carnap
Birth:	May 18, 1891
Death:	September 14, 1970
School/tradition:	Analytic
Main interests:	Logic, Epistemology, Philosophy of Science, Semantics
Notable ideas:	Physicalism, Phenomenalism, Analytic-synthetic distinction, Modal Logic, Constructed language, Conceptual Schemes, Logical Positivism
Influences:	Gottlob Frege, Immanuel Kant, Albert Einstein
Influenced:	W. Quine, David Lewis, Nelson Goodman, David Kaplan, Analytic philosophy

Rudolf Carnap (May 18, 1891, Ronsdorf, Germany – September 14, 1970, Santa Monica, California) was an influential philosopher who was active in central Europe before 1935 and in the United States thereafter.

Life

Carnap was born in a north German family that had been humble until his parents' generation. Carnap then attended the University of Freiburg, where he wrote a thesis setting out an axiomatic theory of space and time. Carnap then wrote another thesis, under Bauch's supervision, on the theory of space from a more orthodox Kantian point of view, published as Carnap (1922).

In 1921, Carnap wrote a fateful letter to Bertrand Russell, who responded by copying out by hand long passages from his Principia Mathematica for Carnap's benefit, as neither Carnap nor Freiburg could afford a copy of this epochal work.

Carnap discovered a kindred spirit when he met Hans Reichenbach at a 1923 conference. Reichenbach introduced Carnap to Moritz Schlick, a professor at the University of Vienna who offered Carnap a position in his department, which Carnap took up in 1926. Carnap thereupon joined an informal group of Viennese intellectuals that came to be called the Vienna Circle, led by Moritz Schlick and including Hans Hahn, Friedrich Waismann, Otto Neurath, and Herbert Feigl, with occasional appearances by Hahn's student Kurt Gödel. When Wittgenstein visited Vienna, Carnap would meet with him.

In 1928, Carnap published two important books:

The Logical Structure of the World, in which he developed a rigorous formal version of empiricism, defining all scientific terms in phenomenalistic terms. It appears, however, that Carnap soon became somewhat disenchanted with this book. This is the notorious position for which Carnap was best known for many years.

In February 1930 Tarski lectured in Vienna, and in November 1930 Carnap visited Warsaw. In 1931, Carnap was appointed Professor at the German language University of Prague. There he wrote the book that was to make him the most famous logical positivist and member of the Vienna Circle, his Logical Syntax of Language (Carnap 1934). In 1933, Willard Quine met Carnap in Prague and discussed the latter's work at some length. Thus began the lifelong mutual respect these two men shared, one that survived Quine's eventual forceful disagreements with a number of Carnap's philosophical conclusions.

Carnap, under no illusions about what the Third Reich was about to unleash on Europe, and whose socialist and pacifist convictions made him a marked man, emigrated to the United States in 1935 and became a naturalized citizen in 1941. From 1936 to 1952, Carnap was a professor of philosophy at the University of Chicago. Thanks in part to Quine's good offices, Carnap spent the years 1939-41 at Harvard, where he was reunited with Tarski. Carnap (1963) later expressed some irritation about his time at Chicago, where he and Charles W. (Their Chicago colleagues included Richard McKeon, Mortimer Adler, Charles Hartshorne, and Manley Thompson.) Carnap's years at Chicago were nonetheless highly productive ones. He wrote books on semantics (Carnap 1942, 1943, 1956), modal logic, coming very close in Carnap (1956) to the now-standard possible worlds semantics for that logic Saul Kripke proposed starting in 1959, and on the philosophical foundations of probability and induction (Carnap 1950, 1952). His writings on thermodynamics and on the foundations of probability and induction, were published posthumously as Carnap (1971, 1977, 1980).

Carnap taught himself Esperanto when he was a mere fourteen years of age, and remained very sympathetic to it (Carnap 1963).

Carnap had four children by his first marriage, which ended in divorce in 1929.

Logician

A good introduction to Carnap the logician is his Introduction to Symbolic Logic with Applications (1958).

Philosophy

For a precis of Carnap's philosophical conclusions, click here.

Academic Genealogy
Notable teachers	Notable students
Bruno Bauch Albert Einstein Gottlob Frege Edmund Husserl	David Kaplan Abner Shimony Howard Stein

Selected publications

1922. University of California Press. University of Chicago Press. University of Chicago Press. University of Chicago Press. University of Chicago Press. University of California Press. University of California Press. University of California Press. Most of Carnap's publications from 1940 onwards can be tracked via the web-based Philosopher's Index, to which most academic libraries subscribe. Erkenntnis Orientated: A Centennial Volume for Rudolf Carnap and Hans Reichenbach. University of Pittsburgh Press. (From the 1929 Vienna Circle manifesto.) When Wittgenstein scolded him for having books about the paranormal in his library, Carnap replied: "But Ludwig, it is only an empirical question."