¹ “The Epistemological Relevance of Mannheim's Sociology of Knowledge,” Journal of Philosophy, Vol. XL (1943), pp. 57–72.

² Ernest Nagel, “Principles of the Theory of Probability,” International Encyclopedia of Unified Science, Vol. I, No. 6, p. 74.

³ Cf. Bergmann, G., and Spence, K. W., “Operationism and Theory in Psychology,” Psychological Review, Vol. XLVIII (1941), pp. 2 ff.

⁴ C. I. Lewis, Mind and the World-Order, Charles Scribner's Sons, New York, 1929, p. 268. What this claim of “new truth,” criticized by Lewis, tends to blur is the distinction between terms and statements as well as that between the adequacy of concepts on the one hand and the truth of laws formulated by means of these concepts on the other. For a careful positivistic analysis of this situation compare G. Bergmann's “Outline of an Empiricist Philosophy of Physics,” American Journal of Physics, Vol. XII (1943).

⁵ Bergmann, op. cit.

⁶ I am referring here in particular to this line of argument as developed in Philipp Frank's recent Between Philosophy and Physics, Harvard University Press, Cambridge, Massachusetts, 1941, pp. 74 ff.

⁷ Cf. Bergmann, op. cit.

⁸ Logic, the Theory of Inquiry, Henry Holt and Company, New York, 1938, p. 519.

⁹ A good example of such treatment of biology is to be found in the writings of J. H. Woodger. Compare both his The Axiomatic Method in Biology, Cambridge, England, 1937, and his more recent monograph, “The Technique of Theory Construction,” International Encyclopedia of Unified Science, Vol. II, No. 5.

Of course Dewey's emphasis upon logic as a product of inquiry is quite understandable and justifiable as criticism of the idealist logic prevailing at the turn of the century. “The motive which actuated the philosophy of Instrumentalism as set forth in Studies in Logical Theory,” claims Dewey, “was a critical reaction to the work of such Post-Kantian logicians Lotze, Bosanquet, and Bradley. The aim was to show that it is not necessary to assume a priori forms of thought to which subject-matter is accommodated, but that logical forms and structures are distinctions within the process of reflective and experimental inquiry.” (Footnote, p. 135, W. P. Montague, The Ways of Knowing, The Macmillan Company, New York, 1925.) For a more complete account of Dewey's motivation cf. M. G. White's The Origin of Dewey's Instrumentalism, Columbia University Press, New York, 1943.

¹⁰ Op. cit., pp. 74–5.

¹¹ Cf. also Gustav Bergmann, “Pure Semantics, Sentences and Propositions,” to appear in Mind. Much of what follows has been suggested by the formulations of this article and in private discussions by its author.

¹² Introduction to Semantics, Harvard University Press, Cambridge, Massachusetts, 1942, p. 28.

¹³ Charles W. Morris, “Foundations of the Theory of Signs,” International Encyclopedia of Unified Science, Vol. I, No. 2, pp. 40–41.

¹⁴ A similar thesis is maintained in Carnap's “Testability and Meaning,” this Journal, Vol. III (1936), pp. 419–471; Vol. IV (1937), pp. 1–40. For criticism see also G. Bergmann, “Remarks concerning the Epistemology of Scientific Empiricism,” this Journal, Vol. IX (1942), pp. 283–293.

¹⁵ ‘Verification basis‘ refers, within a pragmatical system, to those statements of the object language whose names are the simplest arguments for the predicates of verification. The class of these statements will, as a rule, coincide with the basic statements of the object language itself. This, however, is not necessarily the case.

¹⁶ There is perhaps some question as to whether the term ‘verification’, denoting, as it does, an act or process, is the most appropriate one to use in the context of basic statements if these are construed as sentences merely designating certain aspects of single perceptual experiences. In this regard compare Russell's recent assertion that “Verification confirms the more doubtful by means of the less doubtful, and is therefore essentially inapplicable to the least doubtful, viz. judgments of perception.” (Inquiry into Meaning and Truth, W. W. Norton and Company, Inc., New York, 1940, p. 387.) Likewise, though Lewis has indirectly denied the possibility of basic statements so conceived, his claim that “Apprehension of the presented quale, being immediate, stands in no need of verification; ...”, is also relevant here. (Mind and the World-Order, p. 125.)

¹⁷ It is true that much controversy has arisen over the status of basic statements, particularly concerning what is variously referred to as their 'indubitability,' 'unalterability,' 'incorrigibility,' or 'certainty.' At the outset it must be admitted that both the status and form of basic statements are in a sense arbitrary or conventional since they are always relative to the language in question. Owing in part at least to this fact, their unalterability is legitimately assumed for certain “linguistic constructions” undertaken by modern positivists. Nevertheless, in waiving discussion as to their status in applied languages, I have taken for granted throughout that empirical interpretation can be found for unalterable basic statements so long as these latter are treated as sentences which merely denote certain unique features of elementary perceptual experiences. In other words, it has been assumed that empirical application can be given to indubitable factual-atomic-sentences provided they are construed as statements which imply no propositions about future experience. Since no future observation is relevant to the truth or falsity of basic statements so defined, their assertion is at once indubitable and verificatory, and such verification is incorrigible.

If it be further argued that such basic statements are not absolutely certain, then I should hold with Russell (Inquiry into Meaning and Truth) that basic propositions are the “most nearly certain” propositions we have; and that consequently we can be assured there is no other type of more certain propositions by means of which basic statements could be shown false or even probable. (Of course, following Reichenbach. I have used as synonymous terms 'sentence,' 'statement,' and 'proposition,' throughout.)

¹⁸ Vide Neurath, O.: “Protokollsätze,” Erkenntnis, III (1933), pp. 204 ff., and “Radikaler Physikalismus und 'Wirklich Welt,' ” Erkenntnis, IV, (1934), pp. 346 ff.; vide Hempel, C. G.: “On the Logical Positivists' Theory of Truth,” Analysis, Vol. II (1935), pp. 49–59; “Some Remarks on ‘Facts’ and Propositions,” Analysis, Vol. II, (1935), pp. 93–96, and “Some Remarks on Empiricism,” Analysis, Vol. III (1936), pp. 33–40. For criticism of this position vide Russell, op. cit., pp. 174 ff. as well as Ayer's “Verification and Experience,” Proceedings of the Aristotelian Society, N. S. Vol. XXXVII (1936–37), pp. 137–156.