On Explanation: Aristotelean and Hempelean :: History Science Scientific Papers

On Explanation: Aristotelean and Hempelean ABSTRACT: Given the great historical distance between scientific explanation as Aristotle and Hempel saw it, I examine and appraise important similarities and differences between the two approaches, especially the inclination to take deduction itself as the very model of scientific knowledge. I argue that we have good reasons to reject this inclination. In his recent studies showing Galileo's knowledge of and adherence to the deductive standards of explanation in science set forth by Aristotle, Wallace (1) remarks that this Aristotelean theory must not be confused with the contemporary deductive-nomological theory of Hempel and Oppenheim. (2) There are, of course, important differences between the classic works of Aristotle and Hempel, for twenty-three centuries lie between them. But the differences are not as great as might be expected, and, as current discussions of the metatheoretical issues of explanation are generally ahistorical, I believe an attempt to compare these two intellectual mileposts in our understanding of scientific method should prove useful. The most obvious and interesting similarities between the two metatheories of science lie in their deductive character, and this is where their significant contrasts lie as well. Aristotle had developed two major deductive systems: the hypothetical and categorical syllogisms. Of these, he thought only the latter suitable to the demanding rigors of scientific knowledge, whose first characteristics he saw to be 'certainty' and 'necessity'. (3) There are some problematic elements in just what Aristotle took these concepts to mean, but I postpone discussion of that to a later stage. The categorical syllogism, preferably in the familiar "Barbara" of the first figure of the first mood, Aristotle sees to be the ideal supplier of both the certainty and the necessity, with the scientific conclusion being the conclusion of the syllogism. Like Hempel and Oppenheim, he insists that the premises be true, from which it is evident that the conclusion could not fail to be certainly and necessarily true. The syllogism itself, as an argument, then stands as an explanation. Inasmuch as the deductive system of the categorical syllogism can be seen now to be a significant subset of the first-order predicate calculus, which is the deductive system prescribed by Hempel and Oppenheim, the difference between the deductive requirements of the two metatheories is really only that of the greater scope, power, and elegance of the more recent logic. But it remained for Hempel and Oppenheim to point out the