The Meaning of “Motus” in Aquinas’ First Way

Abstract

The 20th Century was a rich period for Thomism. Many commentaries to the First Way were written. One of the many points of disagreement between Thomists was the actual meaning of “motion.” In this paper, I try to argue that one should take for “motion” the broad meaning of “motus” (as equivalent to “mutatio”). I do so by reviewing the position of various prominent Thomists of the last century, many of which have disagreed with this position. I make the case that Aristotle is not the best interpreter of the First Way, and similarly that other works by Aquinas should only be used when the Summa Theologiae itself is not clear enough—which is not the case.