For clarity of thought, although not related to this discussion more than tangentially, I would recommend one German philosopher, Josef Pieper, in his books on the seven virtues, cardinal and theological.
Perhaps his essay on prudence is somewhat relevant, since I have always thought that the change in the presumed definition of prudence from the Aristotelian-Thomist view to what is evident from what Machiavelli assumes in "The Prince" marks a significant turn in our understanding of what is "real" or "realistic"--or "prudent."
The Aristotle tradition would argue that prudence is the virtue or the habit needed to understand what is true or real.
Von Balthasar has also argued for "l'irréductible opposition entre Dieu et la créature." He follows some of the patristics on this point and concludes with them (and Socrates) that human reason is creaturely. This view develops into the teaching of divine incomprehensibility, commonly found in the eastern orthodox churches. There's a different strain running from Augustine to Pope Benedict XVI.
You'll notice right away that this irreducible opposition resembles the opposition of noumena/phenomena in Kant. Kant held that our knowledge stops short of knowing the thing in itself; we don't know the noumena. So our knowledge is on this side of a mystery. What to do? Kant turns reason into a law. He makes a move perfectly parallel to Aristotle. He had to, or he'd be like Socrates, forever not knowing how to act because he doesn't know the big picture. One can never makes sense of the relative without an absolute. But as Voegelin has said, Kant has lost the image of God in his reason. That is, the noumena is effaced.
How does reason remain true in light of mystery? It must be provisional, true in part.
This ties into our earlier discussion of analogy. Here is a profound analogy:
reason : Logos :: law : Spiritwhere reason and law is limited, but logos and Spirit is unlimited.