Of course, he leaves a little bit of wiggle room for complicated problems. There are people who are not morally beautiful that create artistically beautiful works by utilizing the rhythms of eternal beauty. The artist that works in this way, however, will always attach too much value to their own work.
"We must not deny to rhythm...its inclusion within the works of the Divine fabrication, for such rhythm is within its own kind beautiful. But we must not love such rhythm as if it could make us blessed."
Art works may be beautiful, but they cannot make beautiful people. For St. Augustine, only God can do that.
All this is quite difficult to swallow when friends send us video of an artist creating a new work by drinking quantities of colored milk and vomiting it on to a canvas. Is there any room for this kind of thought when petulant human beings like Wagner can create some of the most beautiful music ever written? For that matter, how do we handle the case of the beautiful human being that makes mediocre art work?
The paradigm has shifted to the point where we only teach lessons in the manipulation of the material pertinent to our own artistic discipline. In the old world, they were much more ready to give advice on the shaping of the artists him/herself. I'm not exactly sure how a teacher can do that anymore. I do know that the truly great artists with whom I studied were unselfish and humble. That stuff was rarely communicated in lessons. It happened when we were eating or going to a play or something else.
I suppose all this is to say that those of us who are in the business of training young artists to master their materials also need to take seriously the obligation to mentor them as well. In spite of the rise of the modern academy, there is a very real sense in which the way we pass on our craft is through the old master-apprentice system. If all we do is teach them how to create without teaching them how to live, I'm afraid that we are not really living up to our calling as educators.