Published online by Cambridge University Press: 14 March 2022
In this paper, some qualitative scientific laws are treated in a way that is analogous to the method by which Karl Menger has clarified the nature of quantitative laws such as Boyle's law about ideal gases. The qualitative analogue of the number-valued fluents, such as temperature, are fluents whose domains consist of physical objects while their values are T and F (true and false).
1 E.g., Courant, Differencial and Integral Calculus, vol. 1, p. 16.
2 E.g., Artin, Calculus and Analytic Geometry, Charlottesville 1957, 126pp.
3 Calculus. A Modern Approach, Boston 1955, especially Chapter VII. Cf. also Menger, “An axiomatic theory of functions and fluents” in The Axiomatic Method, ed. Henkin et al., Amsterdam, 1959; “Measuration and other mathematical connections of obserable material” in Measurement: Definitions and Theories, ed. Churchman and Ratoosh, New York, 1959; “Variables, Constants, Fluents” in Current Issues of Philosophy of Science, ed. Feigl and Maxwell, New York, 1961.
4 We henceforword adopt the typographical convention, proposed in the writings loc. cit. ff. 3, that fluents and functions are referred to by symbols in italics (e.g., p. v, cos) while all references to numbers are in roman type.
5 Cf. Henmueller and Menger, “What is Length ?”, Philosophy of Science, Volume 28, 1961, p. 172.
6 See footnote 4.
7 See especially the last publication loc. cit. footnote 3.
8 An interesting paper by W. W. Rozeboom, “Ontological Induction and the Logical Typology of Scientific Variables”, Philosophy of Science, 28, 1961, p. 337, which deals with related problems was published while the present paper was in progress.