This chapter discusses a short work entitled The Proposition of a Manichaean (CPG 6998, 7011), which argues for the existence of two unoriginate first principles, one good and one evil. The Proposition has been transmitted in conjunction with three philosophical works written by Christian authors in the sixth to eleventh centuries (Zacharias of Mitylene’s Adversus Manichaeos, Paul the Persian’s Defensio, and John Italus’ Quaestiones quodlibetales). I provide a critical edition and English translation of the Proposition and show that the text was revised and adapted several times during the course of its transmission. Although a Manichaean origin cannot be securely established for the Proposition, the work was preserved and transmitted because it played a role in later Neoplatonic instruction in logic. The revisions made to the work arose from a need to simplify the text so that students could more easily follow the argument. The discussion and refutation of the Proposition by Christian authors can thus be seen as part of a broader trend toward expanding the study of paralogisms (fallacious arguments) in sixth-century teaching of logic.