Rudolf Carnap: Logic

“For me personally, Wittgenstein was perhaps the philosopher who, besides Russell and Frege, had the greatest influence on my thinking. The most important insight I gained from his work was the conception that the truth of logical statements is based only on their logical structure and on the meaning of the terms. Logical statements are true under all conceivable circumstances; thus their truth is independent of the contingent facts of the world. On the other hand, it follows that these statements do not say anything about the world and thus have no factual content.”

Rudolf Carnap

Source: Carnap’s intellectual biography (1963), p. 25 as cited in: M. J. Cresswell (2010) " Carnap's logic http://apacentral.org/necessity/Cresswell_Carnap.pdf"

Truth , World , Thinking , Personality

“Logic is not concerned with human behavior in the same sense that physiology, psychology, and social sciences are concerned with it. These sciences formulate laws or universal statements which have as their subject matter human activities as processes in time. Logic, on the contrary, is concerned with relations between factual sentences (or thoughts). If logic ever discusses the truth of factual sentences it does so only conditionally, somewhat as follows: if such-and-such a sentence is true, then such-and-such another sentence is true. Logic itself does not decide whether the first sentence is true, but surrenders that question to one or the other of the empirical sciences.”

Rudolf Carnap

Rudolf Carnap (1937) cited in: Irving J. Lee (1967) The Language of Wisdom and Folly: Background Readings in Semantics. International Society for General Semantics, p. 44

Truth , Law , Behavior , Question

“Philosophy is to be replaced by the logic of science -- that is to say, by the logical analysis of the concepts and sentences of the sciences, for the logic of science is nothing other than the logical syntax of the language of science.”

Rudolf Carnap

Foreword
Logical Syntax of Language, 1934/1937

Science

“The function of logical analysis is to analyse all knowledge, all assertions of science and of everyday life, in order to make clear the sense of each such assertion and the connections between them. One of the principal tasks of the logical analysis of a given proposition is to find out the method of verification for that proposition.”

Rudolf Carnap

Rudolf Carnap (1935) Philosophy and Logical Syntax. p. 9-10

Life , Knowledge , Sense , Science

“According to this view, the sentences of metaphysics are pseudo-sentences which on logical analysis are proved to be either empty phrases or phrases which violate the rules of syntax. Of the so-called philosophical problems, the only questions which have any meaning are those of the logic of science. To share this view is to substitute logical syntax for philosophy.”

Rudolf Carnap

Source: Logical Syntax of Language, 1934/1937, p. 8

Question , Problem , Science

“After defining semantical concepts like logical truth and related ones, I proposed to interpret the modalities as those properties of propositions which correspond to certain semantical properties of the sentences expressing the propositions. For example, a proposition is logically necessary if and only if a sentence expressing it is logically true.”

Rudolf Carnap

Source: Carnap’s intellectual biography (1963), p. 62

Truth

“After the new forms are introduced into the language, it is possible to formulate with their help internal questions and possible answers to them. A question of this kind may be either empirical or logical; accordingly a true answer is either factually true or analytic.”

Rudolf Carnap

Source: Empiricism, Semantics, and Ontology (1950), Ch. 3. What does acceptance of a kind of entities mean?

Question , Help

“The task of making more exact a vague or not quite exact concept used in everyday life or in an earlier stage of scientific or logical development, or rather of replacing it by a newly constructed, more exact concept, belongs among the most important tasks of logical analysis and logical construction. We call this the task of explicating, or of giving an explication for the earlier concept; this earlier concept, or sometimes the term used for it, is called the explicandum; and the new concept, or its term, is called an explicatum of the old one.”

Rudolf Carnap

Source: Meaning And Necessity (1947), p. 7-8 as cited in: Erich Reck (2011) " Carnapian Explication: A Case Study and Critique http://www.faculty.ucr.edu/~reck/Reck-C'ian%20Explic.%20(3rd.%20rev.).pdf"

Life

“By the logical syntax of a language, we mean the formal theory of the linguistic forms of that language -- the systematic statement of the formal rules which govern it together with the development of the consequences which follow from these rules. A theory, a rule, a definition, or the like is to be called formal when no reference is made in it either to the meaning of the symbols (for examples, the words) or to the sense of the expressions (e. g. the sentences), but simply and solely to the kinds and order of the symbols from which the expressions are constructed.”

Rudolf Carnap

Source: Logical Syntax of Language, 1934/1937, p. 1

Sense

“Logic is the last scientific ingredient of Philosophy; its extraction leaves behind only a confusion of non-scientific, pseudo problems.”

Rudolf Carnap

Source: The unity of science, 1934/1995, p. 22

Problem