In “New Light on The Mirror of Simple Souls,” Robert Lerner has recently argued that the Middle English version of Marguerite Porete’s Mirouer des simples âmesis the best surviving example of the original Old French text. Other contenders, such as the c. 1500 version made in the Loire valley, now in Chantilly, modernize and effectively translate the work into a separate Middle French dialect. The Middle English text, by contrast, agrees with the anthologized fragments discovered by Geneviève Hasenohr in Valenciennes in 1999—tantalizing bits thought to be in the dialect Marguerite herself might have written. What does it mean for this complicated, heretical treatise to survive not as a French book, but as a glossed—and thereby made orthodox—English one? M.N., the translator, highlights his role as an intermediary between “higher learning” and the common folk—one might even say between the prestige language, French and the edifying vernacular, English. His exemplar, he says, “is yvel written, and in summe places for defaute of wordis and silablesþe reson is aweie.” I argue that we might read this situation as a synecdoche for larger inter-linguistic currents. Just as Chaucer grapples with French sources to create a founding myth for English literature, so does M.N. inadvertently stage the transformation of a work of Continental mysticism into a text in the emerging Middle English genre of “devotional literature.” At the same time, this French beguine’s theology exacts its revenge on M.N.—in spite of Marguerite’s burning, her text lives on across borders, both geographical and linguistic. Here, then, is an example of French as a species of English, an instance of insular categories in a moment of deep suspicion owing a debt to French heresy.