Abstract

Scholars dispute regarding how Aquinas employs the Aristotelian material lying behind his well-known proof of God's existence from motion, the Summa theologiae's 'first way'. The dispute focuses on Aquina's account of this material in Contra gentiles I.13. Aquinas apparently adopts there a 'theory of subordination' by which Aristotle's Physics demonstrates a prime mover that is merely an immanent celestial soul, whereas Aristotle's Metaphysics reasons further to a prior, exclusively final cause of the Physics's prime mover. Yet, this theory, Jean Paulus sees, contradicts the Physics's arrival at God described in Aquinas's Aristotelian commentaries, and Aquinas's 'first way' if identified with the Physics's proof. In resolution of these contradictions, Joseph Owens maintains that Aquinas nowhere takes Aristotle as positing the true God, and that the 'first way' reasons solely through Aquina's unique doctrine of existence. Anton Pegis, by contrast, denies Aquinas any 'theory of subordination', and insists that the 'first way' simply records the Physics's proof of God. ;As an alternative resolution, the dissertation proves that Aquinas consistently presents a 'theory of subordination', but not in the sense previously understood. I offer a reinterpretation of the Aristotelian commentaries, confirmed through parallels in Aquinas's works and through the exegesis of Aristotle by Averroes and Albert the Great. Aquinas, like Albert, adopts Averroes's novel conception of a 'soul' moving the heavens without being their immanent form. For Aquinas, Aristotle's Physics demonstrates a prime mover which may be such a 'soul', or may be God. The Metaphysics, for Thomas, concludes, further, through its own proof from motion, to what can only be the first being or God, both an efficient and a final cause. ;Aquinas as commentator, I conclude, develops a distinctive 'theory of subordination', based, nevertheless, on the 'characteristic medieval approach' to Aristotle's prime mover. By reexamining Aquinas's own 'first way', moreover, I show that it proceeds through the same reasoning which Aquinas discovers in Aristotle's Metaphysics, understanding 'motion' not merely physically or 'existentially', but as the reduction of absolutely any potency into act. Aquinas's subsequent, simplified proof, developed through but different from Aristotle's own, constitutes an unprecedented metaphysical way to God from motion