Notes:

{1} The term rationale Nachkonstruktion was used by Carnap in Der logische Aufbau der Welt ( Berlin and Leipzig, 1928). [Back]

{2} The term "objective fact" taken in the original sense of the word "objective" would express the same point; but we avoid it, as the word "objective" suggests an opposition to "subjective," an opposition which we do not intend. [Back]

{3} Cf. the author's Philosophie der Raum-Zeit- Lehre (Berlin: De Gruyter, 1928), § 12. [Back]

{4} The words "sentence" and "statement" are also in use. But this distinction being of little importance and rather vague, we shall make no distinction between ' "propositions" and "sentences" and "statements." [Back]

{5} A. Tarski, "Der Wahrheitsbegriff in den formalisierten Sprachen" Studia Philosophica (Warsaw, 1935); cf. also Actes du Congres International de Philosophie Scientifique (Paris: Hermann & Cie., 1936), Vol. III: Langage, containing contributions of A. Tatski and Marja Kokoszynska concerning the same subject. Another contribution of Marja Kokoszynska is to be found in Erkenntnis, Vl (1936), 143 ff. [Back]

{6} C. G. Hempel, "On the Logical Positivist's Theory of Truth," Analysis, II, No. 4 (1935), 50. [Back]

{7} This has been recently emphasized by Carnap, "Testability and Meaning," Philosophy of Science, III (1936)] 420. [Back]

{8} Cf. the author's Philosophie der Raum-Zeit- Lehre, § 34. [Back]

{9} Although this formula is not verbally contained in Wittgenstein's Tractatus logico-philosophicus (London 1922), it expresses his ideas very adequately and has been used, with this intention, within the "Vienna Circle." [Back]

{10} Cf. W. James, Pragmatism (New York, 1907), Lecture VI: "How will the truth be realized? What experiences will be different from those which would obtain if the belief were false? What, in short, is the truth's cash value in experiential terms?" This idea goes back to the pragmatic maxim of C. S. Peircc, first pronounced in 1878: "Consider what effects, that might conceivably havc practical bearings, we conceive the object of our conception to have. Then, our conception of these effects is the whole of our conception of the object" (Collected Papers of C. S. Peirce, V, Cambridge, Mass., 1934, 1). The logical development of the theory inaugurated by this formula is due mainly to James, Dewey, and Schiller. [Back]

{11} As to the rules of the probability implication, see the author's Wahrscheinlichkeitslehre (Leiden: Sijthoff, 1935), § 9. [Back]

{12} We follow, in the exposition of the different functions of language, ideas developed by Ogden, Bühler, and Carnap. [Back]

{13} We invoke here psychological facts but leave the question as to the character of psychological facts to a later investigation (cf. § 26). [Back]

{14} Among my former publications concerning the probability theory of meaning, I may mention the following. The idea that empirical propositions are not to be conceived as two-valued entities but are to bc dealt with as having a "truth-value" within a continuous scale of probability (a view which demands that they be considered within a probability logic) was first expounded by me at the first congress of "Erkenntnislehre der exakten Wissenschaften" in Prague in 1929 (cf. Erkenntnis, I [1930], 170-73). A continuation of these ideas was presented to the following congress, held in Königsberg in 1930 (cf. ibid., II [1931], 156-71). The construction of the probability logic demanded by me has been carried through, in the form of a logistic calculus (including the theory of modalities), in my paper "Wahrscheinlichkeitslogik," Berichte der Berliner Akademie Wissenschaften (math.-phys. Kl. [1932] ); cf. also my book Wahrscheinlichkeitslehre. The two principles of the probability theory of meaning given in § 7 were first formulated in "Logistic Empiricism in Germany and the Present State of Its Problems," Journal of Philosophy, XXXIII, No. 6 (March 12, 1936), 147-48 and 154. [Back]

{15} Op. cit., p. 181. [Back]

{16} "Wahrheit und Bewährung," Actes du Congres International de Philosophie Scientifique, 1935 (Paris, 1936), IV, 18; "Testability and Meaning," Philosophy of Science, III (1936), 420, and ibid., IV (1937), 1. [Back]

{17} Cf. the discussion on the congress of Prague, 1929, reported in Erkenntnis, I (1930), 268-70. [Back]