This article considers the attempt by a prominent fifteenth-century follower of Thomas Aquinas, Dominic of Flanders (a.k.a. Flandrensis, 1425-1479), to address John Duns Scotus’ most famous argument for the univocity of being. According to Scotus, the intellect must have a concept of being that is univocal to substantial and accidental being, and to finite and infinite being, on the grounds that an intellect cannot be both certain and doubtful through the same concept, but an intellect can be certain that something is a being while doubting whether it is a substance or accident, finite or infinite. The article shows how Flandrensis’ reply in defence of analogy of being hinges on a more fundamental disagreement with Scotus over the division of the logically one. It also shows how Flandrensis’ answer to this question commits him to a position on the unity of the concept of being that lies between the positions of Scotus and of Flandrensis’ earlier Thomistic sources.