Historical Rhetorics/Rhetoric's Medieval Resurgence/Fulkerson, Gerald. "Augustine's Attitude Toward Rhetoric in 'De Doctrina Christiana': the Significance of 2.37.55."
Fulkerson looks at thematic similarities between books II and IV in De Doctrina Christiana and concludes that, despite the time lapse between their compositions, Augustine’s continual “hostility toward perceptive rhetoric was not a product of his old age.” (110) He concludes that focusing so intently on the mission of the Christian teacher forces rhetoric to take a back seat to usefulness.
Fulkerson sees book IV as an extension of book II. Where book II sets out guidelines for what a Christian preacher should study (What is useful to the interpretation of the scriptures, only what is useful, and nothing excessively), book IV focuses on the utility of eloquence rather than its artfulness.
While eloquence is “of great value in urging evil or justice” and “should therefore be obtained for the uses of the good in the service of truth” Fulkerson sees Augustine as subjugating they study of style to the service and spreading of the scriptures. Rhetoric, for Augustine, is not useful as a persuasive tool so much as it is potentially distracting from the mission of the Christian preacher.