1. Having reinforced his earlier claims about the order of the sciences and the dignity of sacra doctrina as true wisdom, St. Thomas proceeds to clear up further questions about the nature and extent of this science. In this article he asks whether it is correct to say that God is the object of theological science.
2. Against this, two difficulties are raised: first, that in an ordinary science (as we observed in the treatment of article two above) the first principles of the science concern the definition of its object. Sacred doctrine, however, does not define God, nor can it, given his nature.
3. Second, that whatever the object of a science is, all the conclusions of that science ought to concern the nature and activity of the object. Sacra doctrina, however, reaches conclusions about many things which are not God.
4. The treatment of this questions is largely a repetition of previous statements, though St. Thomas adds an interesting reflection on the nature and distinction of habits. However, to resolve the objections quickly without wasting too much time rehashing established points, it suffices to say the following: first, that everything considered in sacred doctrine is considered as being related to God either in himself, or as an effect of his power, or as tending toward him as its perfection. Second, that though God's essence cannot be defined (for good reason, to be discussed later on), sacred doctrine employs various signs and effects, given to us through nature or through grace, to signify the divine essence, which suffices in the present life in place of the proper definition, which being utterly simple is available only to the blessed.
Outline of Article
–The object of a science is defined by the science.
–The conclusions of a science all concern its object.
–God is the object of sacra doctrina.
–Other objects are treated secondarily.
–Since the divine nature is indefinable for us, in sacra doctrina we employ natural or supernatural effects in place of a definition to grasp at the essence of God.
–All the conclusions of sacred doctrine deal with God at least indirectly: whether as an aspect of his nature or an extension of his power.