St. Thomas called art “reason in making.” This is a very cold and very beautiful definition, and if it is unpopular today, this is because reason has lost ground among us. As grace and nature have been separated, so imagination and reason have been separated, and this always means an end to art. The artist uses his reason to discover an answering reason in everything he sees. For him, to be reasonable is to find, in the object, in the situation, in the sequence, the spirit which makes it itself. This is not an easy or simple thing to do. It is to intrude upon the timeless, and that is only done by the violence of a single-minded respect for the truth.
I wonder what Flannery means by “reason” when she says that “reason has lost ground among us.” She must mean more than narrow rationalism or intellectualism, which seem to be gaining rather than losing. I suspect she means something along the lines of the (metaphysical) glue that holds all that exists in its divinely ordained order: reason, in that understanding, is the Word and Wisdom of God which makes cosmos (rather than chaos). That has certainly lost ground. We live in chaos.
By this definition, it makes sense that the artist’s reason can discover “an answering reason in everything he sees.” That makes sense because the classic catholic vision is that everything coheres in God. A deep likeness makes all things kin, despite appearances.
Finding in things “the spirit which makes it itself” comes at a cost. The cost is self-emptying– what Flannery is alluding to when she mentions the artist’s “single-minded respect for the truth.” That single-mindedness of the artist is the turning away from ego-satisfaction, and the turning toward contemplation: away from self-absorption, toward absorption in the sensible world. Or, as Flannery says in another place, there’s nothing not worthy of the writer’s stare.