Abstract
This paper takes up a disagreement between Augustine and John of Damascus on the relation of the persons of the Trinity to the divine essence. Whereas Augustine rejects speaking of God as a genus or species with the divine persons as subordinate species or individuals, Damascene uses such an analogy freely in different writings. Peter Lombard sides with Augustine but allows for Damascene’s language according to metaphor or similitude. The purpose of this paper is to utilize the trinitarian theology and metaphysical categories of Thomas Aquinas to examine the nature of the unity characteristic of universals like species and whether, in his account, one may predicate such a universal to the Godhead. To this end, the concepts of analogy, essence, person, unity, plurality, transcendental multitude, predication, genus, species, individuation, universality, particularity, communicability, and incommunicability will be examined in detail. I will argue that ultimately an analogy of genus or species cannot properly be applied to the Trinity because it contradicts the doctrine of divine simplicity. The unity of the universal insufficiently characterizes the divine unity of essence. On the other hand, Aquinas does allow for a reading of Damascene similar to that of the Lombard, to the extent that, according to our limited mode of knowledge, the relationship of individuals to a species can help us to understand the mode of communicability unique to God’s essence.