Probabilist - Deductive Inference in Gassendis Logic Essay -- Philoso

‘Probabilist’ Deductive Inference in Gassendi's Logic* ABSTRACT: In his Logic, Pierre Gassendi proposes that our inductive inferences lack the information we would need to be certain of the claims that they suggest. Not even deductivist inference can insure certainty about empirical claims because the experientially attained premises with which we adduce support for such claims are no greater than probable. While something is surely amiss in calling deductivist inference "probabilistic," it seems Gassendi has hit upon a now-familiar, sensible point—namely, the use of deductive reasoning in empirical contexts, while providing certain formal guarantees, does not insulate empirical arguments from judgment by the measure of belief which we invest in their premises. The more general point, which distinguishes Gassendi among his contemporaries, is that the strength shared by all empirical claims consists in the warrant from experience for those claims we introduce in their support. In Book IV (On method) of his Institutio Logica, Pierre Gassendi proposes an unusual venue for probable and nondeductive inference in empirical reasoning: demonstrative syllogism. Thus, in 'resolution'—the seeking of a thing's causes given the evidence of its effects—he recognizes the critical role of inferring general claims from the particulars of empirical data, not least from what he calls 'the evidence of signs'. And intriguingly, he construes resolution-based claims as merely probable, though we attain them through classically deductive syllogism, because they represent merely possible claims among a field of alternatives—perhaps in the manner of Descartes's method. In the preceding book (On the syllogism), Gassendi presents a relatively tradit... .... Garber, Daniel. "Descartes and Experiment in the Discourse and Essays," in Stephen Voss, Essays on the Philosophy and Science of Rene Descartes. New York and Oxford: Oxford University Press, 1993. Gassendi, Pierre. Institutio Logica, 1658. Hacking, Ian. The Emergence of Probability. Cambridge: Cambridge University Press, 1985. Hatfield, Gary. "Science, Certainty, and Descartes", in PSA 1988: Proceedings of the Biennial Meeting of the Philosophy of Science Association. Volume Two. 249-262. East Lansing, Michigan: Philosophy of Science Association, 1988. Hintikka, Jakko. "Aristotelian Induction," in Revue Internationale de Philosophie 34 (1980): 422-40. Milton, J. R. "Induction before Hume," British Journal for the Philosophy of Science 38 (1987): 49-74. Urbach, Peter. Francis Bacon's Philosophy of Science. La Salle, Illinois: Open Court, 1987.