Drawing from the “Writing Bilingually Catalogue”, a new database currently being developed at the Warburg Institute, the essay explores how self-translations (works translated by the authors themselves) can yield a more nuanced understanding of Latin-vernacular dynamics in early modern Europe, with particular attention to France. Challenging established narratives of a longstanding pre-eminence of Latin in technical domains such as theology, philosophy, and law, the essay shows how self-translations did not always flow from Latin into French, but also from French into Latin or across both languages simultaneously, depending as much on authors’ views of language as on genre, intended audience, and contextual factors such as political events and broader cultural processes. Directionality thus emerges as a useful but problematic category that needs closer investigation in the context of early modern translation cultures.