This essay examines two versions of an essay by Adrienne Rich on Anne Bradstreet to argue that Rich's intervening relationship with Audre Lorde facilitated her development of a rhetorical technique I call additive emendation. This method allowed her to supplement the original essay so as to both comment on its errors and let them remain evident to the reader. Lorde's emphasis on knowledge as an ongoing phenomenon rather than a finite commodity, and her understanding of prose as a means to inscribe that process, informed this technique and became evident to Rich in a series of contentious print exchanges between them. As such, the three pairings in this essay—Rich and Bradstreet, Lorde and Rich, and Rich's later and earlier authorial personae—reflect the feminist phenomenon of the open letter, whereby anger, rather than critical dispassion, founds argumentative cogency.