Chapter “Sade, Language and Modality” turns to Sade’s philosophy of language and modality. It reviews Sade’s claim that the world is a totality of possibilities rather than facts or actualities, and evaluates a kinship between his thought and that of Heidegger and Kant. It connects this position with his linguistic conventionalism, as espoused in Pensée among other texts, and his commitment to ineffability.