1. Having established that sacra doctrina is a single discipline which covers diverse subjects inasmuch as they are all divinely revealed, St. Thomas asks whether it is a speculative or practical science. In a way, this article is an extended reply to one of the difficulties raised in the previous article. Theology considers both ethical questions and speculative questions. Is it primarily a practical discipline, oriented toward right action, or a speculative discipline, oriented toward the truth about some object?
2. In favor of the claim that theology is a practical science, he quotes the letter of St. James: "Be doers of the word, and not only hearers," and points out that revelation is divided into two covenantal law codes: the Old Law (of Moses) and the New Law (of Christ). Since James seems to see knowledge of sacred doctrine as terminating in action, and since the purpose of law is to properly order one's actions, it would seem that sacred doctrine is primarily practical, and meant to direct us to act in a certain way.
3. However, Thomas concludes that sacred doctrine is primarily speculative, since practical sciences are concerned chiefly with human activities and the perfection thereof, but sacred doctrine is primarily concerned with God. Furthermore, to the extent that sacred doctrine deals with practical matters, it is for the sake of a greater knowledge of God, tending toward the perfect vision of the Divine Essence, "in which consists eternal bliss."
4. This article seems trivial, but its significance is in demonstrating that the point of theology is primarily to know the truth, and not primarily to elicit good actions. Good works should flow from knowledge of the truth, but Thomas will insist throughout the Summa that to understand is a more perfect act than to will.
Outline of Article
–Only practical sciences terminate in action.
–Revelation is divided into two codes of Law, and law concerns action.
–Practical sciences are concerned with human operations; sacred doctrine is concerned with God.
–Sacred doctrine is concerned with practical matters inasmuch as they are caused by God as creator and tend toward him as ultimate end.