Articles 4 and 5 have some very interesting and helpful parsing of the act of faith, but I want to hold off on commenting on the until I look at Question 2, which is all about the act of faith. For the moment, let me just note that in Article 5, reply to objection 2, St. Thomas says that the reason we consider theology to be a science is because it draws out conclusions from first principles. And it is interesting to note that he does not say “Sacred Doctrine,” but theologia.
As an aside, I bought Reginald Garrigou-Lagrange’s commentary on these questions of the Summa. As I grew up as a thinker, I went through a long period where I didn’t want to read Lagrange’s stuff–or any of the Neo-Scholastic writers, really. But now I find that I like to pick them up, because they are kind of Joseph Fitzmyer for thomists: I don’t want to write or think like them, but they’re dang handy to have on the shelf.
And in fairness, I have to say that Lagrange’s spiritual writings strike me as profound and sincere, springing from a lived experience of God.