Aquinas and Scotus on the Metaphysical Foundations of Morality

This paper retraces some of the contrast between Aquinas and Scotus with respect to the metaphysical foundations of morality in order to highlight how subtle differences pertaining to the relationship between the divine will and the divine intellect can tip a thinker toward either an unalloyed natural law theory (NLT) or something that at least starts to move in the direction of divine command theory (DCT). The paper opens with a brief consideration of three distinct elements in Aquinas's work that might tempt one to view him in a DCT light, namely: his discussion of the divine law in addition to the natural law; his position on the so-called immoralities of the patriarchs; and some of his assertions about the divine will in relation to justice. We then respond to each of those considerations. In the second and third of these cases, following Craig Boyd, we illustrate how Aquinas's conviction that the divine will follows the ordering of the divine intellect can help inform the interpretive disputes in question. We then turn our attention to Scotus's concern about the freedom of the divine will, before turning to his discussion of the natural law in relation to the Decalogue as a way of stressing how his two-source theory of the metaphysical foundations of morality represents a clear departure from Aquinas in the direction of DCT.