Stephen L. Brock

Since Hume, there has been broad consensus that if the notion of the good has any intelligible foundation, it is not “ontological”, in the natures of things. Today however this view is being challenged. After a sketch of the positions of Kant and Hume, and a glance at some of the recent challenges, the paper examines a key element in Thomas Aquinas’s ontol- ogy of the good: the notion of nal causality. For Thomas nal causality presupposes formal and e cient causality. Hume’s denial of the intelligibility of the good, it is su ested, presup- poses his denial of that of these other causes.

Focusing mainly on two passages from the Summa theologiae, the article first argues that, on Aquinas’s view, an individual substance, which is the proper subject of being, can and normally does have a certain multiplicity of acts of being. It is only “a certain” multiplicity because the substance has only one unqualified act of being, its substantial being, which belongs to it through its substantial form. The others are qualified acts of being, added on to the substantial being through accidental forms. Having established this thesis, the rest of the article uses it as a basis for an approach to the so-called real distinction between act of being and essence or between act of being and substantial form. This approach is meant to be effective even in an Aristotelian setting where there may seem to be no place for a substantial act distinct from substantial form.