This article shows how two concepts for which Blaise Pascal's Pensées (1670) are best known—divertissement and ennui (often mistranslated as “boredom”)—inherited and transformed medical conceptions of melancholy along with one of melancholy's signature therapeutic protocols: diversion. Instead of limiting the genealogy of Pascal's concepts to more obvious textual sources (St Augustine, Montaigne, etc.), here they are read against the background of an epistemological paradigm dominant in his time: Galenic medicine. Drawing on a large corpus of early modern French medical texts, this article discloses how melancholy, stripped of its overt medical status, remerges in Pascal's analysis of subjectivity, which valorized melancholic ennui against the values of a nascent civil society subservient to the monarchic order. Once used to describe outlying temperaments and exceptional pathologies, the discourse on melancholy becomes fundamental to the human being per se in Pascal's theological and anthropological perspective. Thus transformed, the older forms of melancholy and its remedies ensured the possibility of their survival—disguised and unrecognized—in modern theories of subjectivity and psychology. Understanding melancholy's latent presence in the Pensées, in other words, sheds new light on the affective aspects of Pascal's social critique and invites us to investigate the modern afterlife of early modern melancholy.