One of the things I am doing while on research leave is trying to finish a book on Augustine. It is an introduction, and is being written for Christian Focus in Scotland. It is--to say the least--a tad intimidating to try and write an "Introduction" (!!!) to Augustine. But on we go. I am working through Etienne Gilson's The Christian Philosophy of Saint Augustine. On page 69 Gilson is discussing Augustine on the nature of teaching, and whether a teacher really teaches anything at all (a sobering thought for a professor).
Here is Gilson on Augustine:
"When a teacher instructs a pupil, does he put into the pupil's mind the ideas signified by the words he uses? In short, is there such a thing as teaching?"