This article looks at the place of Longinus in Goulu’s Lettres de Phyllarque à Ariste (1627-8), written in response to the publication of Guez de Balzac’s collected volumes of letters. It pays close attention to Goulu’s translations of sections of On the Sublime, considering the ways in which Goulu’s praise of Longinus connects with his dispraise of Balzac. Goulu tries (problematically) to use Longinus to show that Balzac exceeds the bounds of vivid, plausible and persuasive discourse.