Since this article is intended to be primarily a piece of exegesis, I have thought it best to include ample references so that anybody so inclined is in a position to follow up or check any particular statement. But for the sake of the scurrying reader, I have also tried to simplify the notation of such references, as follows: All references, unless otherwise stated, are to the Summa Theologiae, and the first figure or couplet of figures denotes the Book of the Summa, the second figure denotes the Question within that Book, a third the Article within that Question, and any possible further symbol denotes either the corpus of the Response to the Question or the Reply to an objection (or both). Thus, for example, 1–2, 3, 4 in c. and ad 2 would denote the first part of the second Book, the third Question, and the corpus of the Response as well as the Reply to the second objection in the fourth Article.