¹ Philosophy of Science, 3, (1936), 418-471; 4, (1937), 1-40.

² Koehler, W., The Place of Values in a World of Facts (New York: Liveright Publishing Corporation, 1938).

³ Feigl, H., “Unity of Science and Unitary Science,” Journal of Unified Science, I, (1939).

⁴ A similarly dangerous and misleading hyperphysicalization of psychology, the confusion between “logical behaviorization” and universal “experimentability” has been discussed in a previous paper, “On some methodological problems of psychology,” Philosophy of Science, 7 (1940), 205-219.

⁵ Allport, G. W., “The psychologist's frame of reference,” Presidential address delivered at the meeting of the American Psychological Association, (1939).

⁶ Specific problems arising from the fact that psychoanalytic theory is an M-language must be distinguished from the general requirement of ‘logical behaviorization’ of psychoanalysis. As to the latter, see the article quoted, footnote 4, 197-236.

⁷ Bernfeld, S., “Zur Revision der Bioanalyse,” Imago, 23, 1937. Some psychoanalytical approaches to the social sciences raise similar problems. See Bergmann, G., “Zur analytischen Theorie literarischer Wertmasstaebe,” Imago, 21, 1935, 498-506.

⁸ See Feigl, H., “Logical analysis of the psychophysical problem,” Philosophy of Science, 1, 1934, pp. 420-445; an integration and elaboration of the “contribution of the new positivism” to this issue, anticipating most of the results of consistent language analysis.

⁹ Skinner, B. F., “The behavior of organisms,” (New York: D. Appleton-Century Company, 1938), Chapters I, XIII.

¹⁰ Of Course the expression ‘meaningful’ must not be understood here as a methodological term. Also in some other respects the diction has been loosened in this and later paragraphs. Where no danger of confusion exists, the material idiom has been used for convenience.

¹¹ There is no contradiction between this expectation and the previous statement that no meaningful behavioristic approach can disregard the linguistic material. In such a theoretical B-structure all linguistic behavior may be located on the level of introduced terms and derived laws.

¹⁸ The thesis of strict physicalism is the affirmative answer to this empirically open question. It should also be noted that the expressions ‘replaced by’ and ‘reduced to’ as used here must be understood in the sense of factual isomorphism (§ 4).

¹³ This necessary distinction must not be interpreted as a criticism of Koehler's thought. It should rather help to appreciate this powerful, anticipatory vision as what it is, the legitimate heir of the great German tradition of natural philosophy, brought to the standards of present time empirical science. As to its linguistic and physicalistic interpretation, see also a previous paper, “On physicalistic models of non-physical terms.” Philosophy of Science, 7 (1940), 151–158.

¹⁴ Boring, E. G., Psychophysiological Systems and Isomorphic Relations. Psychological Review, 43 (1936), 565-587.