Abstract
In his many and varied writings, St Thomas presents us with both a sophisticated account of human action and a complicated moral theory. In this article, I shall be considering the question of whether St Thomas’s theory of action and his moral theory are mutually consistent. My claim shall be that St Thomas can preserve the ontological unity of human action—but only at the cost of rendering it extremely difficult to evaluate in a manner consistent with his moral theory, or, alternatively, that he can provide a viable ethical analysis of human action—but only at the cost of compromising its ontological unity. In the first section of this article I shall examine St Thomas’s account of a particular kind of moral action, namely lying. Two basic questions concerning the specificity of unicity of human action will emerge from this examination: 1) what makes an act to be a specific moral act?, and 2) what makes a specific moral act to be one act? In the second section of the article I shall attempt to show, by means of a textual examination, that St Thomas does not appear to be able to provide an account of human action that will satisfactorily answer both these basic questions at the same time.