Does the Latinate vernacular capture non-Europhone relationships of speech to writing? Surveying non-equivalences between the vernacular and its East/South translations, I focus on the Arabic ʿāmmiyya. Vernacular hails from verna, the slave born on his master’s estate; ʿāmmiyya, from al-ʿāmma, the common people. Long-ninth-century Arab-Islamic thought defined al-ʿāmma as a “middle” class, or its language and that of al-khāṣṣa (the elite) as shades of one Arabic, converging at an ideal midpoint. I trace echoes in late-nineteenth-century Algerian, Syro-Lebanese, and Egyptian theory, which derived ʿāmmiyya (dialect) from fuṣḥā (standard) or redefined fuṣḥā as a generalist language that ideally addresses a middle audience. I suggest that a long (if suppressed) continuity in Arabic between common and elite language, if not between dialect and standard, opens horizons of relation between speech and writing different from those the vernacular ushered into Europhone contexts. Reframing language as medium, such horizons limn a polycentric literary comparatism.