Rudolf Carnap Biography


(History of the World: The 20th Century)

Article abstract: Carnap is recognized as a leading figure in the philosophy of logical positivism and made significant contributions to logic, the theory of probability, philosophy of science, and linguistic analysis.

Early Life

Rudolf Carnap was born in Ronsdorf in northwestern Germany on May 18, 1891. His parents were deeply religious and did not want to expose their children to secular influences. Consequently, both Rudolf and his sister were educated by their mother at home. His father died when Rudolf was seven years old, and his mother continued to supervise his education until he left for the Universities of Jena and Freiburg in 1910. For four years, Carnap studied physics, philosophy, and mathematics. While studying at Jena, Carnap attended the lectures of Gottlob Frege, widely acknowledged as the most eminent logician of his time. Frege deeply influenced Carnap’s future work, although at that moment, Carnap’s interest lay in the physics of electrons. Carnap began his doctoral dissertation in physics when World War I began. He spent three years at the front and, in 1917, was transferred to Berlin to work on developing wireless communication for the army. For Carnap, the period of the war created an awareness of his pacifism and the irrationality of violent human conflict, and confirmed his belief in the values of rationality and science.

Carnap returned to philosophy in 1919 and at the same time encountered the works of Bertrand Russell. Frege had earlier sparked an interest in logic, and now Russell renewed that interest. The idea that symbols could take the place of sentences and that sentences operate with each other in a limited number of ways led Carnap to write a dissertation on an area that bordered both philosophy and physics. In 1921, he completed his work and received his Ph.D. from Jena with a thesis that compared the concepts of space used in physics, mathematics, and philosophy.

For several years, Carnap was content to work independently in areas of logic and physics. He wrote a number of articles on space, time, and causality, and began work on a textbook on symbolic logic. In 1926, he was invited to teach at the University of Vienna, and this turned out to be the decisive step toward an important career in philosophy.

Life’s Work

When Carnap was invited to become an instructor at the University of Vienna in 1926, he was ready to begin a unique exploration of one philosophical area. Moritz Schlick, who had arranged the invitation to Vienna, also formed the Vienna Circle that year by bringing together philosophers, mathematicians, linguists, and other scholars. Schlick wanted to develop a system of philosophy in which all statements could be rigorously verified by logic. Carnap became a leading member of the Circle and from their discussions shared in the initial ideas of logical positivism or logical empiricism.

Before going to Vienna, Carnap had begun to organize his interest in mathematical logic. Frege recommended a reading of Principia Mathematica (1910-1913), a masterful work on logic by Russell and Alfred North Whitehead which attempted to derive all of mathematics from a set of premises. Deeply influenced by this work, Carnap in 1924 completed a first draft of a textbook on mathematical logic entitled Abriss der Logistik mit besonderer Berücksichtigung der Relationstheorie und ihrer Anwendungen. It was first published in 1929 and later translated into English from a considerably different version in 1958 as Introduction to Symbolic Logic and Its Applications. Carnap arrived in Vienna in 1926 and began his duties as an instructor at the university. During the next five years, he actively participated in conversation with the members of the Vienna Circle, taught, and wrote.

During this period in Vienna, Carnap became one of the leading advocates for a philosophical position called logical positivism or logical empiricism. This school of thought synthesized the empiricism of David Hume and, combined with the revolution in modern physics, attempted to create a precise and rigorous philosophy that claimed all human knowledge originated from immediate experience. For Carnap, the culmination of these five years was the publication in 1928 of Der Logische Aufbau der Welt (the logical construction of the world). Carnap organized all the objects of the world into four main types: socio-cultural objects, others’ minds, physical objects, and personal experiences. By accepting the human ability to remember similarities, Carnap built a system of knowledge where comparison between similarities would lead to the creation of a temporal order. Carnap believed that a person’s experience at any given moment was created from a series of elements and that these series...

(The entire section is 1980 words.)

Rudolf Carnap Biography

(Survey of World Philosophers)

Article abstract: Carnap became leader of the logical positivists. They regarded logic, mathematics, and physics as genuine knowledge, but metaphysics and ethics as cognitively meaningless. Carnap’s main strategy was to construct artificial languages in formal symbolism.

Early Life

Rudolf Carnap was born in northwest Germany to parents who were earnestly religious but tolerant of the beliefs of others. During adolescence, his studies of science led him to drop his religious beliefs in favor of secular humanism. He attended the Universities of Jena and of Freiburg im Breisgau, studying mathematics, physics, and philosophy.

At Jena, between 1910 and 1914, Carnap attended the classes of Gottlob Frege, a philosophical mathematician little known at that time. Frege had anticipated Alfred North Whitehead and Bertrand Russell by originating quantificational symbolism in logic and using it in the attempt to demonstrate rigorously that all mathematics of number is strictly reducible to logic. Under Frege’s influence, Carnap came to distinguish sharply between symbols and what the symbols stand for, thereby avoiding much confusion in the philosophy of mathematics, and also to distinguish sharply between analytic truths (knowable on the basis of principles of pure logic together with explicit definitions) and synthetic truths (knowable only on the basis of some kind of immediate experience). However, Carnap rejected Frege’s metaphysical views about the reality of abstract entities.

Carnap’s studies were interrupted by military service in World War I. On his return, he committed himself to graduate work in philosophy. His doctoral dissertation, published in 1922, dealt with the philosophy of space. It was influenced by the neo-Kantianism he had absorbed from his professors, but it also showed his keen interest in new developments in physics. Soon his philosophical work began to show the influence of Russell, who in 1914 had called for a new breed of thinkers who would resolve philosophical problems by using the techniques of mathematical logic to construct formalized systems.

Life’s Work

Carnap’s philosophical career began to blossom in 1925 when he was invited to lecture at the University of Vienna, where Moritz Schlick had assembled a group of philosophers, mathematicians, and scientists actively concerned with the philosophy of science. This group held regular meetings and came to be known as the Vienna Circle. They were impressed by Carnap, and Schlick obtained a teaching position, starting in 1926, in philosophy at Vienna for Carnap. Carnap later looked back on this period as a time of especially fruitful discussion and cooperative research among this lively group of largely like-minded thinkers. Carnap began to play a leading role in the drafting of manifestoes and the editing of publications aimed at spreading the philosophically radical doctrines of this new movement, and his writings soon became more extensive and influential than those of any other member. The movement came to be called logical positivism, though Carnap preferred to call it logical empiricism.

The members of the Vienna Circle had been impressed by Ludwig Wittgenstein’s “Logisch-philosophische Abhandlung” (1921; best known by the bilingual German and English edition title of Tractatus Logico-Philosophicus, 1922, 1961) and drew some of their doctrines from it. However, Wittgenstein did not find Carnap congenial; Carnap’s conception of philosophy could hardly have pleased him. Carnap’s view was that the goal of philosophy should be to work out rational reconstructions of scientific language that needed clarifying. In each case, his strategy was to construct a formalized artificial language containing precisely defined symbols that could serve as improved replacements for the terms occurring in ordinary scientific discourse. For him, these were just technical problems requiring technical solutions. Carnap had no interest in the mystical or in other philosophical perplexities with which Wittgenstein became obsessively concerned.

Carnap’s most important work from his Vienna period was The Logical Structure of the World. In this book, he attempted to sketch a rational reconstruction of all talk about physical objects in the world. He tried to show how, in a formalized language, sentences using physical-object terminology could in principle be completely translated into sentences that merely report immediate sense experience. This was Carnap’s reformulation of the view that earlier philosophers had termed phenomenalism. It became part of the program for what Carnap called the “unity of science,” his goal being a single, logically unified language system in which all science could be expressed.

Russell had already worked on this project, but Carnap’s treatment was fuller. Even Carnap, however, left the project very incomplete, with many logical gaps unbridged. Notably, rather than starting with sentences about small bits of sensory content as Russell had, Carnap, under the influence of Gestalt psychology, began with sentences about momentary total experiences. Also, unlike Russell, Carnap did not think it imperative to treat immediate experience as the starting point. He mentioned that sentences about publicly observable physical objects could also serve as an acceptable starting point. Thus, he showed his cavalier attitude toward the traditional idea that empirical knowledge of objects must be based on private sensory experience. He held that choice of a starting point is merely a matter of convenience.

After five years in Vienna, Carnap moved to the German University of Prague, where he remained through 1935, continuing to maintain contact with his colleagues in Vienna. During his Prague period, he published a very readable short book, Philosophy and Logical Syntax, in which he provides a forceful statement of the overall...

(The entire section is 2446 words.)