My first post on Catholic Theology may be found here.
For Protestants (and Karl Barth is one prominent example), reason is not a reliable means of knowledge about God, at least not for Theology Proper (though one does find appeals to reason in Protestant apologetics; e.g. C. S. Lewis and N. T. Wright). As I understand it, Barth was reacting to the philosophers of his day who could endlessly defer talking about the actual subject matter of Scripture because they first had to establish through reason the existence of God. Their kind of reason was not the Socratic, open kind, but a critical variety with an anti-supernatural bias. But if we turn back the clock even farther, before these anti-supernatural philosophers, we find that Thomas Aquinas shares the optimism of the CCC*. He sees reason as a gift that is later revised and clarified by the gift of revelation (see his Summa, Question 1).
So my Protestant readers (most of you!) may have a follow-up question on the issue of Natural Theology. At least, I did. My question was this:
“Man’s faculties make him capable of coming to a knowledge of the existence of a personal God. But for man to be able to enter into real intimacy with him, God willed both to reveal himself to man and to give him the grace of being able to welcome the revelation in faith. The proofs of God’s existence, however, can predispose one to faith and help one to see that faith is not opposed to reason.” (§35, emphasis mine).
Catholic teaching is clear—even our faith in God is a gift. Without his grace, we would not be able to put our trust in the God who has revealed himself to us. Perhaps, too, Natural Theology does not sound so foreign when situated in its context. The main difference between Catholics and Protestants on Natural Theology is the degree of depravity that resulted from the Fall or the degree of optimism that remains about human reason. On one thing we agree—grace is always necessary for salvation.
*Catechism of the Catholic Church