Rudolf Carnap
Rudolf Carnap was a German philosopher who was active in Europe before 1935 and in the United States thereafter. He was a major member of the Vienna Circle and an advocate of logical positivism.
Biography
Carnap's father rose from being a poor ribbon-weaver to be the owner of a ribbon-making factory. His mother came from an academic family; her father was an educational reformer and her oldest brother was the archaeologist Wilhelm Dörpfeld. As a ten-year-old, Carnap accompanied Wilhelm Dörpfeld on an expedition to Greece. Carnap was raised in a profoundly religious Protestant family, but later became an atheist.He began his formal education at the Barmen Gymnasium and the Gymnasium in Jena. From 1910 to 1914, he attended the University of Jena, intending to write a thesis in physics. He also intently studied Immanuel Kant's Critique of Pure Reason during a course taught by Bruno Bauch, and was one of the very few students to attend Gottlob Frege's courses in mathematical logic.
During his university years, he became enthralled with the German Youth Movement.
While Carnap held moral and political opposition to World War I, he served in the German army. After three years of service, he was given permission to study physics at the University of Berlin, 1917–18, where Albert Einstein was a newly appointed professor. In August 1918 Carnap joined the Independent Social Democratic Party and worked as a journalist for left-wing newspapers. He then attended the University of Jena, where he wrote a thesis defining 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 in 1921, under Bauch's supervision, on the theory of space in a more orthodox Kantian style, published as Der Raum in a supplemental issue of Kant-Studien.
Frege's course exposed him to Bertrand Russell's work on logic and philosophy, which gave a sense of direction to his studies. He accepted the effort to surpass traditional philosophy with logical innovations that inform the sciences. He wrote a letter to Russell, who responded by copying by hand long passages from his Principia Mathematica for Carnap's benefit, as neither Carnap nor his university 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 accepted in 1926. Carnap thereupon joined an informal group of Viennese intellectuals that came to be known as the Vienna Circle, directed largely by Schlick and including Hans Hahn, Friedrich Waismann, Otto Neurath, and Herbert Feigl, with occasional visits by Hahn's student Kurt Gödel. When Wittgenstein visited Vienna, Carnap would meet with him. He wrote the 1929 manifesto of the Circle, and initiated the philosophy journal Erkenntnis.
In February 1930, Alfred Tarski lectured in Vienna, and during November 1930, Carnap visited Warsaw. On these occasions, he learned much about Tarski's model-theoretic method of semantics. Rose Rand, another philosopher in the Vienna Circle, noted, "Carnap's conception of semantics starts from the basis given in Tarski's work, but a distinction is made between logical and non-logical constants, and between logical and factual truth... At the same time, he worked with the concepts of intension and extension, and took these two concepts as a basis of a new method of semantics."
In 1931, Carnap was appointed Professor at the German University in Prague. In 1933, W. V. 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, whose socialist and pacifist beliefs put him at risk in Nazi Germany, emigrated to the United States in 1935 and became a naturalized citizen in 1941. Meanwhile, back in Vienna, Schlick was murdered in 1936. From 1936 to 1952, Carnap was a professor of philosophy at the University of Chicago. During the late 1930s, Carnap offered an assistant position in philosophy to Carl Gustav Hempel, who accepted and became one of his most significant intellectual collaborators. Thanks partly to Quine's help, Carnap spent the years 1939–41 at Harvard University, where he was reunited with Tarski. Carnap 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. Carnap's years at Chicago were nonetheless very productive ones. He wrote books on semantics, modal logic, and on the philosophical foundations of probability and inductive logic.
After a stint at the Institute for Advanced Study in Princeton, he joined the UCLA Department of Philosophy in 1954, Hans Reichenbach having died the previous year. He had earlier refused an offer of a similar job at the University of California, Berkeley, because accepting that position required that he sign a loyalty oath, a practice to which he was opposed on principle. While at UCLA, he wrote on scientific knowledge, the analytic–synthetic distinction, and the verification principle. His writings on thermodynamics and on the foundations of probability and inductive logic were published posthumously as Carnap.
Carnap taught himself Esperanto when he was 14 years of age. He later attended the World Congress of Esperanto in Dresden in 1908. He also attended the 1924 Congress in Vienna, where he met his fellow Esperantist Otto Neurath for the first time.
In the US, Carnap was somewhat politically involved. Carnap was a signatory of an open appeal distributed by the National Committee to Secure Justice in the Rosenberg Case to appeal for clemency in the case. He was listed as a 'sponsor' for the "National Conference to Appeal the Walter-McCarran Law and Defend Its Victims" organised by the American Committee for the Protection of the Foreign Born, and also for the "Scientific and Cultural Conference for World Peace" organised by the National Council of Arts, Sciences and Professions.
Carnap had four children by his first marriage to Elizabeth Schöndube, which ended in divorce in 1929. He married his second wife, Elizabeth Ina Stöger, in 1933. Ina committed suicide in 1964.
Philosophical work
Below is an examination of the main topics in the evolution of the philosophy of Rudolf Carnap. It is not exhaustive, but it outlines Carnap's main works and contributions to modern epistemology and philosophy of logic.''Der Raum''
From 1919 to 1921, Carnap worked on a doctoral thesis called Der Raum: Ein Beitrag zur Wissenschaftslehre. In this dissertation on the philosophical foundations of geometry, Carnap tried to provide a logical basis for a theory of space and time in physics. Considering that Carnap was interested in pure mathematics, natural sciences and philosophy, his dissertation can be seen as an attempt to build a bridge between the different disciplines that are geometry, physics, and philosophy. For Carnap thought that in many instances those disciplines use the same concepts, but with totally different meanings. The main objective of Carnap's dissertation was to show that the inconsistencies between theories concerning space only existed because philosophers, as well as mathematicians and scientists, were talking about different things while using the same "space" word. Hence, Carnap characteristically argued that there had to be three separate notions of space. "Formal" space is space in the sense of mathematics: it is an abstract system of relations. "Intuitive" space is made of certain contents of intuition independent of single experiences. "Physical" space is made of actual spatial facts given in experience. The upshot is that those three kinds of "space" imply three different kinds of knowledge and thus three different kinds of investigations. It is interesting to note that it is in this dissertation that the main themes of Carnap's philosophy appear, most importantly, the idea that many philosophical contradictions appear because of a misuse of language, and a stress on the importance of distinguishing formal and material modes of speech.''Der Logische Aufbau der Welt''
From 1922 to 1925, Carnap worked on a book which became one of his major works, namely Der logische Aufbau der Welt, which was accepted in 1926 as his habilitation thesis at the University of Vienna and published as a book in 1928. That achievement has become a landmark in modern epistemology and can be read as a forceful statement of the philosophical thesis of logical positivism. Indeed, the Aufbau suggests that epistemology, based on modern symbolic logic, is concerned with the logical analysis of scientific propositions, while science itself, based on experience, is the only source of knowledge of the external world, i.e. the world outside the realm of human perception. According to Carnap, philosophical propositions are statements about the language of science; they aren't true or false, but merely consist of definitions and conventions about the use of certain concepts. In contrast, scientific propositions are factual statements about the external reality. They are meaningful because they are based on the perceptions of the senses. In other words, the truth or falsity of those propositions can be verified by testing their content with further observations.In the Aufbau, Carnap wants to display the logical and conceptual structure with which all scientific statements can be organized. Carnap gives the label "constitution theory" to this epistemic-logical project. It is a constructive undertaking that systematizes scientific knowledge according to the notions of symbolic logic. Accordingly, the purpose of this constitutional system is to identify and discern different classes of scientific concepts and to specify the logical relations that link them. In the Aufbau, concepts are taken to denote objects, relations, properties, classes and states. Carnap argues that all concepts must be ranked over a hierarchy. In that hierarchy, all concepts are organized according to a fundamental arrangement where concepts can be reduced and converted to other basic ones. Carnap explains that a concept can be reduced to another when all sentences containing the first concept can be transformed into sentences containing the other. In other words, every scientific sentence should be translatable into another sentence such that the original terms have the same reference as the translated terms. Most significantly, Carnap argues that the basis of this system is psychological. Its content is the "immediately given", which is made of basic elements, namely perceptual experiences. These basic elements consist of conscious psychological states of a single human subject. In the end, Carnap argues that his constitutional project demonstrates the possibility of defining and uniting all scientific concepts in a single conceptual system on the basis of a few fundamental concepts.