Programme
Jon Bornholdt
University of Würzburg
Aquinas, Maimonides, and the Tertia Via: Source, Structure, and Context
Modern discussions of Aquinas’ “Tertia Via” argument for the existence of God (S.T. I q2 a3 c.) have focused on three issues: (1) the possible sources of the argument, (2) its structure, and (3) its place within Aquinas’ broader metaphysical and physical commitments as a scholastic Aristotelian. In this paper I argue, on structural, textual, and conceptual grounds, for one of the earliest modern interpretations of the Tertia Via, according to which one of its main sources is indeed the “Third Argument” from Part II of Maimonides’ Guide of the Perplexed. This interpretation assumes that Aquinas is positing, for the purposes of this argument, an eternal world, and that his use of the terms quandoque and aliquando refer to the relative future rather than the relative past or to metaphysical dependency relations. I then offer a defense of the apparent “quantifier shift” in the first step of the argument: given a few reasonable assumptions about the conceptual structure of the argument, Aquinas can be acquitted of the charge of formal fallacy.