The rhetorical figure of paradiastole (the redescription of vices as virtues) offers important insight into Satan’s temptation discourse in Paradise Lost. This article argues that Milton deliberately employs the rhetorical ambiguity of paradiastole to mimic the interpretive challenge that instances of temptation present to the practice of ethical discernment. Milton’s case for “trial by what is contrary” offers an interpretive context to meet this challenge. After addressing the difficulties inherent in understanding paradiastole and the principles from Milton’s prose that help one to do so, the article analyzes the figure’s operation in the temptation discourses of books 5 and 9. In Satan’s paradiastolic speeches, Milton presents readers with sufficient clues to discern, even if Eve does not, whether the claims to virtuous intent can be sustained.