|Birth:||May 18, 1891|
|Death:||September 14, 1970|
|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. V. O. 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. He was a leading member of the Vienna Circle and a prominent advocate of logical positivism.
Carnap was born in a north German family that had been humble until his parents' generation. He began his formal education at the Barmen Gymnasium. From 1910 to 1914, he attended the University of Jena, intending to write a thesis in physics. But he also carefully studied Kant's Critique of Pure Reason in a course taught by Bruno Bauch, and was one of very few students to take Frege's courses in mathematical logic. After serving in the German army during WW I for three years, he was given permission to study physics at the University of Berlin, 1917-18, where Albert Einstein was a newly appointed professor. Carnap then attended the University of Freiburg, where he wrote a thesis setting out an axiomatic theory of space and time. The physics department said it was too philosophical, and Bruno Bauch of the philosophy department said it was pure physics. 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. In 1924 and 1925, he attended seminars led by Edmund Husserl, the founder of phenomenology, and continued to write on physics from a logical positivist perspective.
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. He (with Hahn and Neurath) wrote the 1929 manifesto of the Circle, and (with Hans Reichenbach) founded the philosophy journal Erkenntnis.
In 1928, Carnap published two important books:
In February 1930 Tarski lectured in Vienna, and in November 1930 Carnap visited Warsaw. On these occasions he learned much about Tarski's model theoretic approach to semantics. 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. Meanwhile back in Vienna, Moritz Schlick was assassinated in 1936. 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. Morris were the only members of the department committed to the primacy of science and logic. (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).
After a stint at the Institute for Advanced Study at Princeton, he joined the philosophy department at UCLA in 1954, Hans Reichenbach having died the previous year. He had earlier declined an offer of a similar position at the University of California, because taking up that position required that he sign a McCarthy-era loyalty oath, a practice to which he was opposed on principle. While at UCLA, he wrote on scientific knowledge, the analytic - synthetic dichotomy, and the verification principle. 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). He later attended a World Congress of Esperanto and employed the language while traveling.
Carnap had four children by his first marriage, which ended in divorce in 1929. His second wife committed suicide in 1964.
A good introduction to Carnap the logician is his Introduction to Symbolic Logic with Applications (1958). There we find:
For a precis of Carnap's philosophical conclusions, click here.
|Notable teachers||Notable students|
Online bibliography. Under construction, with no entries dated later than 1937. Most of Carnap's publications from 1940 onwards can be tracked via the web-based Philosopher's Index, to which most academic libraries subscribe.