Rudolf Carnap: Quotes about doubt

“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

“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

“For those who want to develop or use semantical methods, the decisive question is not the alleged ontological question of the existence of abstract entities but rather the question whether the rise of abstract linguistic forms or, in technical terms, the use of variables beyond those for things (or phenomenal data), is expedient and fruitful for the purposes for which semantical analyses are made, viz. the analysis, interpretation, clarification, or construction of languages of communication, especially languages of science.”

Rudolf Carnap

Source: Empiricism, Semantics, and Ontology (1950), Ch. 5. Conclusion

Communication , Question , Decision , Science

“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

“If someone wishes to speak in his language about a new kind of entities, he has to introduce a system of new ways of speaking, subject to new rules; we shall call this procedure the construction of a linguistic framework for the new entities in question.”

Rudolf Carnap

Source: Empiricism, Semantics, and Ontology (1950), Ch. 2. Linguistic frameworks

Way , Question

“To be sure, we have to face at this point an important question; but it is a practical, not a theoretical question; it is the question of whether or not to accept the new linguistic forms. The acceptance cannot be judged as being either true or false because it is not an assertion. It can only be judged as being more or less expedient, fruitful, conducive to the aim for which the language is intended. Judgments of this kind supply the motivation for the decision of accepting or rejecting the kind of entities.”

Rudolf Carnap

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

Motivation , Question , Decision , Falseness