Rudolf Carnap

From Philosopedia

Rudolf Carnap (18 May 1891 - 14 September 1970)

Carnap was a German-American philosopher, a logical positivist and author of The Logical System of Language (1937).

From 1910 to 1914, Carnap attended the University of Jena, intent upon writing his thesis about 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.

While attending the University of Freiburg, he wrote a thesis setting out an axiomatic theory of space and time. The physics department said it was too philosophical, and 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 to Bertrand Russell, who responded by copying out by hand long passages from his Principia Mathematica for Carnap's benefit, as neither Carnap nor his school at 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.

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. The formal system of the Aufbau, as this book is often called by virtue of the first word of its German title, was grounded in a single primitive dyadic predicate, which is satisfied if two individuals "resemble" each other. The Aufbau was greatly influenced by Principia Mathematica, and warrants comparison with the mereotopological metaphysics A. N. Whitehead developed over 1916-29. It appears, however, that Carnap soon became somewhat disenchanted with this book. In particular, he did not authorize an English translation until 1967.
• Pseudoproblems in Philosophy asserted that many philosophical questions were meaningless, i.e., the way they were posed amounted to an abuse of language. An operational implication of this radical stance was taken to be the elimination of metaphysics from responsible human discourse. This is the notorious position for which Carnap was best known for many years.

Contents 1 The 1930s and On 2 Popper on Carnap 3 Carnap on Labeling 4 An Overview of Carnap's Life and Works 5 Selected publications

The 1930s and On

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 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 (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 (1942, 1943, 1956), modal logic, coming very close in 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 in 1950 and 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.

Popper on Carnap

Eugene Yue-Ching Ho in May of 1992 was one of those invited by Sir Karl Popper to celebrate his 90th birthday. Following were his memories of the members of the Vienna Circle:

We then turned to the subject of Twentieth Century philosophy and he began reflecting upon some members of the Vienna Circle, whom he knew personally in his young days. Rudolf Carnap, in his view, was "a neurotic man". To substantiate his point, he recounted light-heartedly how Carnap sought the help of a psychoanalyst upon reading his (Popper's) critical essay, "The Demarcation between Science and Metaphysics", written as a contribution to the Schilpp volume The Philosophy of Rudolf Carnap. He did not have any good things to say about the philosophical capability of the other Vienna Circle members either. Of Victor Kraft, he said that he "was a nice man who spoke quite interesting things, [though] not very exciting, and not always right." Of Otto Neurath, he remarked that he was "a very lovable person who had quite a lot of ideas. [He was an] original person, but he was a Communist, and a very naive Communist. He actually went to Moscow to persuade the Communists to give up materialism and replace it with physicalism." Of Hans Reichenbach, his criticism was very harsh: "Reichenbach was not a nice man, not [even] a decent man. [He] behaved very badly, [and] he swindled [intellectually]." Finally, of Carl Hempel, he simply said that "he is impossible. He has never had an idea of his own." Popper's overall view of the Vienna Circle was that it was a circle of politics: "You see, these prominent members of Carnap's circle were all philosophical politicians; that is to say, they belonged together and cooperated in a philosophical politics of making their circle strong."

Sir Karl did, however, have some good words to say about other philosophers, such as Willard Quine and Bertrand Russell. He showed a particular reverence for Russell's intellectual acumen and spoke favourably of his Principia Mathematica, the seminal work on mathematical logic. But Russell's political thinking did not appeal to him: "I loved Russell, but there was a moment when he really turned mad. During the Cuban crisis he was sending telegrams accusing Kennedy of provoking a war and congratulating Khrushchev on his mildness."

But in regard to the latest philosophical scene, Popper admitted that he was not familiar with both the philosophers and their ideas, for he was disappointed by many of these high-sounding and pretentious theories and was therefore no longer interested in doing philosophy. I remember him lamenting:

I think so badly of philosophy that I don't like to talk about it...I do not want to say anything bad about my dear colleagues, but the profession of teacher of philosophy is a ridiculous one. We don't need a thousand of trained, and badly trained, philosophers - it is very silly. Actually most of them have nothing to say.

Carnap on Labeling

In 1954, when Warren Allen Smith asked his views about a categoriztion of seven categories of humanism, Carnap replied,

• I should say that among the positions outlined I would choose naturalistic or scientific humanism as nearest to my position. (I would not like the label “religious humanism.” Indeed, “atheistic humanism” would fit better, but this should, of course, not be interpreted in the sense of existentialism.) I find myself in agreement with the basic attitudes as explained in Corliss Lamont’s book, disregarding minor differences in questions of epistemology and the like.

An Overview of Carnap's Life and Works

Rudolf Carnap, a German-born philosopher and naturalized U.S. citizen, was a leading exponent of logical positivism and was one of the major philosophers of the twentieth century. He made significant contributions to philosophy of science, philosophy of language, the theory of probability, and classical, inductive and modal logic. He rejected metaphysics as meaningless because metaphysical statements cannot be proved or disproved by experience. He asserted that many philosophical problems are indeed pseudo-problems, the outcome of a misuse of language. Some of them can be resolved when we recognize that they are not expressing matters of fact, but rather concern the choice between different linguistic frameworks. Thus the logical analysis of language becomes the principal instrument in resolving philosophical problems. Since ordinary language is ambiguous, Carnap asserted the necessity of studying philosophical issues in artificial languages, which are governed by the rules of logic and mathematics. In such languages, he dealt with the problems of the meaning of a statement, the different interpretations of probability, the nature of explanation, and the distinctions between analytic and synthetic, a priori and a posteriori, and necessary and contingent statements.

{Mauro Murzi, "Internet Encyclopedia of Philosophy"]

Selected publications

• 1922. Der Raum: Ein Beitrag zur Wissenschaftslehre, Kant-Studien, Ergänzungshefte, no. 56. His Ph.D. thesis.
• 1926. Physikalische Begriffsbildung. Karlsruhe: Braun.
• 1928. Scheinprobleme in der Philosophie (Pseudoproblems of Philosophy). Berlin: Weltkreis-Verlag.
• 1928. Der Logische Aufbau der Welt. Leipzig: Felix Meiner Verlag. English translation by Rolf A. George, 1967. The Logical Structure of the World: Pseudoproblems in Philosophy. University of California Press.
• 1929. Abriss der Logistik, mit besonderer Berücksichtigung der Relationstheorie und ihrer Anwendungen. Springer.
• 1934. Logische Syntax der Sprache. English translation 1937, The Logical Syntax of Language. Kegan Paul.
• 1996 (1935). Philosophy and Logical Syntax. Bristol UK: Thoemmes.
• 1939, Foundations of Logic and Mathematics in International Encyclopedia of Unified Science, Vol. I, no. 3. University of Chicago Press.
• 1942. Introduction to Semantics. Harvard Uni. Press.
• 1943. Formalization of Logic. Harvard Uni. Press.
• 1956 (1947). Meaning and Necessity: a Study in Semantics and Modal Logic. University of Chicago Press.
• 1950. Logical Foundations of Probability. University of Chicago Press.
• 1950. Empiricism, Semantics, Ontology, Revue Internationale de Philosophie 4: 20-40.
• 1952. The Continuum of Inductive Methods. University of Chicago Press.
• 1958. Introduction to Symbolic Logic with Applications. Dover.
• 1963, "Intellectual Autobiography" in Schilpp (1963: 1-84).
• 1966. Philosophical Foundations of Physics. Martin Gardner, ed. Basic Books.
• 1971. Studies in inductive logic and probability, Vol. 1. University of California Press.
• 1977. Two essays on entropy. Shimony, Abner, ed. University of California Press.
• 1980. Studies in inductive logic and probability, Vol. 2. Jeffrey, R. C., ed. University of California Press.

(See Norman M. Martin’s entry for Carnap in the Encyclopedia of Philosophy, Vol. 2.) {CE; HNS; WAS, 13 August 1954}