Page 528 - Encyclopedia of Philosophy of Language

Key Figures
For almost half a century Rudolf Carnap (1891-1970) was one of the dominant figures in analytic phil- osophy. He was a leading member of the Vienna Circle, and subsequently exercised a formative influ- ence on the development of philosophy in the USA. His major contributions lie in such areas as logic, semantics, the foundations of mathematics, and the philosophy of science.
1. Carnap'sLife
Carnap was born and grew up in the Barmen region of northwest Germany. Between 1910 and 1914 he studied mathematics, physics, and philosophy, first at the University of Freiburg, and then at Jena where he was taught mathematical logic by Gottlob Frege. In 1926 he moved to Vienna and joined the Vienna Circle. During this period the major influences on his thought were Gottlob Frege, Bertrand Russell, and Ludwig Wittgenstein. After five years in Vienna, Car- nap moved to Prague on being appointed to the Chair of Natural Philosophy in the German University. Confronted by the rise of National Socialism, however, he left Europe for the USA, where he remained for the rest of his life. He held chairs of philosophy at Chicago (1936-52), Princeton (1952- 54), and UCLA (1954-61), and by the time of his death in 1970 he had published over 20 books and 80 articles on philosophy.
2. Positivism
As a lifelong logical positivist, or logical empiricist, Carnap was committed to the view that every item of human knowledge falls into one of two mutually exclusive categories. Either the knowledge is substan- tive, in which case it can only originate in or be jus- tified by observation and experience; or the knowledge is merely formal and is expressed in propositions that are 'tautological, that is, they hold necessarily in every possible case, and therefore do not say anything about the facts of the world.' This view allows that both synthetic propositions of natural science, and analytic propositions of logic and mathematics possess an intelligible cognitive content, but it denies that any such content can be possessed by the sentences of traditional metaphysics. The problems of metaphysics thus become pseudo-problems to which no solution is possible (Carnap 1932). Traditional philosophy, he announced, 'is to be replaced by the logic of science,' and this is 'nothing other than the logical syntax of the language of science' (Carnap 1934: Foreword).
3. LogicalSyntax
During the period 1928-38 Carnap held the view that problems concerning the cognitive content of scientific sentences are a matter for the particular science in question: they will be substantive problems belonging to physics, botany, psychology, and the like. But as there is no cognitive content to sentences of meta- physics, the only task remaining to the philosopher is to investigate the pure forms of possible scientific sentences. These pure syntactic structures are, he believed, conventional: they are systems of rules gov- erning permissible combinations or concatenations of signs, regardless of what those signs might mean. No language, syntactically defined, is intrinsically more accurate or more basic than any other. On the con- trary one is free to invent notations and to use them as and how one sees fit. Caraap's Principle of Tol- erance says that in philosophy: 'It is not our business to set up prohibitions, but to arrive at conventions' (Carnap 1934:51). At this time Carnap believed that logic, mathematics, and (bona fide) philosophy were all essentially syntactical disciplines; all other (bona
fide) disciplines belonged within the empirical sciences.
4. Semantics
By about 1939, under the influence of Gddel and Tarski, Carnap had come to see that not all the philo- sophically important properties of language can be given a purely syntactical interpretation: there are also semantic and pragmatic properties that need to be taken into account.
Carnap defines a semantical system as 'a system of rules [i.e., definitions], formulated within a meta- language and referring to an object language, of such a kind that the rules determine a truth-condition for every sentence of the object language, i.e., a sufficient and necessary condition for its truth' (Carnap 1942:22). A semantical system (a) assigns a deno- tation to appropriate subsentential expressions of a language, and (b) provides a recursive definition of truth for the sentences of that language. Typically the object languages studied by Carnap were formalized (not natural) languages, whereas the metalanguage he employed was usually a natural language like English, supplemented by special symbols and expressions wherever necessary.
In later works Carnap applied his semantic analyses to intentional and modal contexts (1956), and to inductive logic and the foundations of probability (1950).
See also: Linguistic Philosophy; Logical Positivism.
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