357–381

The Arians and Eunomius against the Cappadocians: Is God's Essence Knowable?

The fundamental idea of the Arian doctrine of God, according to Pelikan, is "one and only": God is the unbegotten, unoriginate "monad," who cannot share his attributes with anyone, and "God was not always Father." The Anomoeans Aetius and Eunomius, advisers of Eudoxius (from 357), went further than Arius: the words "unbegotten" and "begotten" express a difference of essence between Father and Son, and God can be comprehended with complete precision. The Cappadocians began their struggle against Eunomius with the question of God's knowability. Basil: "We know the greatness of God, his power, goodness... but not his essence"; Gregory of Nyssa: the more the mind knows God, the more it is convinced of its ignorance.