SOURCE: "Action Theory in St. Thomas Aquinas" in Miscellanea Mediaevalia, Walter de Gruyter & Co., 1987, pp. 13-22.

In the following essay, written in 1987, McInerny examines Aquinas's thoughts on the common good and ultimate end, particularly the distinction between conceiving and realizing perfection.

In this paper I shall be discussing an issue in Thomistic moral theory that seems to have its parallel in Aristotle. Students of Aristotle have often considered the relation between the analysis of decision in Nicomachean Ethics III, where the model is an end/means one, and that in Nicomachean Ethics VI and VII, where the preferred model is the practical syllogism, to be problematical. A similar difficulty can be raised about the relation between the opening discussions of the Summa theologiae, Iallae, (and not only qq. 1-5, but also the whole sweep of discussions from q. 6 through q. 17), and the discussion of natural law later on...