¹ Goodman, Nelson, Fact. Fiction, and Forecast (The Bobbs-Merrill Company, Indianapolis, 1965);Google Scholar and Hempel, Carl G., ‘Studies in the Logic of Explanation', Sections 6 and 7, and ‘Aspects of Scientific Explanation', especially pp. 338-343, Aspects of Scientific Explanation (The Free Press, New York, 1965).Google Scholar

² A. J. Ayer, ‘What is a Law of Nature?', Revue Internationale de Philosophie (Brussels, Belgium), No. 36, fasc. 2 (1956); and Braithwaite, R. B., Scientific Explanation (Cambridge University Press, Cambridge, 1953)Google Scholar. Ayer's article and a relevant selection from Braithwaite's book are reprinted in B. Brody (ed.), Readings in the Philosophy of Science (Prentice-Hall, Inc., Englewood Cliffs, N.J., 1970).

³ The sentences resulting from the instantiation of extensional sentential schemata, in other words, are eternal rather than occasion sentences in the sense of W. V. O. Quine, Word and Object (The M.I.T. Press, Cambridge, 1960), pp. 191-195.

⁴ Quine, W. V. O., Mathematical Logic (Harper and Row, New York, 1951), p. 11.CrossRefGoogle Scholar

⁵ For the purposes of chemistry, for example, a classification of elements on the basis of such structural properties as atomic weight and atomic mass has proven useful; for the purposes of biology, a classification of organisms on the basis of phylogenetic and genetic properties has proven useful; and so on.

⁶ Not every named thing, as Pap appears to think; cf. Arthur Pap, ‘Reduction Sentences and Disposition Concepts', in P. A. Schilpp (ed.), The Philosophy of Rudolf Carnap (Open Court, La Salle, 111., 1963), pp. 593-597; and see also Camap's reply, pp. 948-949.

⁷ A finite frequency interpretation is advanced by Russell, Bertrand, Human Knowledge: Its Scope and Limits (Simon and Schuster, New York, 1948), pp. 350-362.Google Scholar Classical limiting frequency interpretations are Reichenbach, Hans, The Theory of Probability (University of California Press, Berkeley, 1949);Google Scholar and Mises, Richard von, Mathematical Theory of Probability and Statistics (Academic Press, New York, 1964).Google Scholar

⁸ Quine, Mathematical Logic, p. 29.

⁹ Kyburg, Cf. Henry, Philosophy of Science: A Formal Approach (The Macmillan Company, New York, 1968), pp. 313-317.Google Scholar

¹⁰ For an analysis of some significant consequences attending their confusion, see James H. Fetzer, ‘Griinbaum's “Defense” of the Symmetry Thesis', Philosophical Studies (April, 1974). The present investigation discloses the principles that underlie all such misunderstandings; for although the extensional implications of lawlike statements, for example, may perfectly well serve the purposes of prediction and retrodiction, only intensional formulations are sufficiently strong for the purpose of explanation.

¹¹ Popper, Karl, The Logic of Scientific Discovery (Harper and Row, New York, 1960)Google Scholar, p. 433. Popper's formulation has been subjected to criticism by G. C. Nerlich and W. A. Suchting, ‘Popper on Law and Natural Necessity', British Journal for the Philosophy of Science 18 (1967), pp. 233-35. This critique plus Popper's rejoinder and many other related papers are published together in Tom Beauchamp, ed., Philosophical Problems of Causation (Dickenson Publishing Company, Belmont, Calif., 1974). With respect to the present explication, Popper's formulation is ambiguous unless it is specified that all permanent and transient dispositional properties of things are kept constant, i.e., they remain permanent and transient properties of things of just the same kinds.

¹² The theory of explanation that attends this explication of lawlikeness is set forth in James H. Fetzer, ‘A Single Case Propensity Theory of Explanation', Synthese (October, 1974). See also note 21 for a non-trivial clarification.

¹³ An intriguing alternative to the present account of dispositions is provided by D. H. Mellor, ‘In Defense of Dispositions', Philosophical Review (April, 1974).

¹⁴ Goodman, Fact, Fiction, and Forecast, p. 41.

¹⁵ Fetzer, James H., ‘Dispositional Probabilities', Boston Studies in the Philosophy of Science, Vol. VIII, R. Buck and R. Cohen (eds.), D. Reidel Publishing Company, (Dordrecht, Holland, 1971)Google Scholar; and Fetzer, James H., ‘Statistical Probabilities: Single Case Propensities vs. Long Run Frequencies', Developments in the Philosophy of Social Science, W. Leinfellner and E. Kohler (eds.), (D. Reidel Publishing Company, Dordrecht, Holland, 1974).Google Scholar

¹⁶ Ibid. The latter includes a discussion of the relevant principles of relevance.

¹⁷ All lawlike conditionals that are true are maximally specific as follows: if a nomically relevant predicate is added to the reference class description (i.e., to the description of K,relative to χ or of K.T, relative to 0), then either the resulting statement is a logical truth (by virtue of the fact that its antecedent condition is now self-contradictory) or it is logically equivalent to the original statement (since the additional relevant predicate is actually redundant). Cf. Carl G. Hempel, ‘Maximal Specificity and Lawlikeness in Probabilistic Explanation', Philosophy of Science (June, 1968), p. 131.

¹⁸ A lucid summary of the most important results involved in these investigations is provided by Hempel, Carl G., Fundamentals of Concept Formation in Empirical Science (University of Chicago Press, Chicago, 1952), Part II.Google Scholar

¹⁹ Pap, op. cit., p. 560.

²⁰ Pap mistakenly believes that ‘the distinctive property of causal implication as compared with material implication is just that the falsity of the antecedent is no ground for inferring the truth of the causal implication’; see Arthur Pap, ‘Disposition Concepts and Extensional Logic’, Minnesota Studies in the Philosophy of Science, Vol. II, H. Feigl, M. Scriven, and G. Maxwell (eds.), (University of Minnesota Press, Minneapolis, 1958), p. 212. Davidson purports to demonstrate that the causal connective cannot be a conditional of any kind, essentially on the basis of his observation that, ‘My tickling Jones would cause him to laugh, but his not laughing would not cause it to be the case that I didn't tickle him’; ‘Causal Relations’, Journal of Philosophy (November 9, 1967), pp. 691-695.

²¹ More precisely, explanations for the occurrence of singular events require the causal formulation of lawlike statements, while the subjunctive formulation of these same statements appears to be appropriate for explaining why particular objects happen to possess certain specified properties.

²² Counterfactual attributions, in other words, are - implicitly or explicitly - equivalent to conjunctions of the form, ‘’, e.g., which, in turn, may be accounted for on the basis of the fact that m is a member of K and . Counterfactuals, therefore, are properly understood as special kinds of subjunctives, i.e., as instantiated subjunctives with historically false antecedents.