The Aristotelian categories are a fundamental element in Eriugena’s philosophical system on account of his realist view of dialectic. He received his texts concerning the categories from Boethius and the De decem catagoriis, but key ideas in his treatment of them—namely, the metaphysical importance of dialectic, the unknowability of essence, and the origin of being in place and time, ideas fundamentally rooted in Byzantine developments of the Christology of Chalcedon—are taken from Maximus the Confessor. Eriugena’s work on the categories represents (...) an attempt, much misunderstood, to assimilate the richness of the Eastern tradition to Western philosophical and theological method. This paper examines the synthesis of Maximus’s ideas with Ciceronian and Boethian elements in Eriugena’s striking treatment of the Aristotelian Categories. (shrink)