ABSTRACT In antiquity, rhetorical treatises generally identified clarity and obscurity as positive and negative qualities of style, respectively. But in the fifth century, Augustine developed a valuation such that both clarity and obscurity could potentially function as equally viable resources for persuasion. While previous rhetorical treatises acknowledged that standards of perspicuity varied with genre, Augustine's stipulations for variability are tied much more closely to the particulars of the rhetorical situation. In a bold vision of the potency of style, Augustine demonstrates how a principle like clarity can be adjusted according to the rhetorical situation.