We make the Holy Scriptures the canon and the rule of every dogma; we of necessity look upon that, and receive alone that which may be made conformable to the intention of those writings.On the Soul and Resurrection
We do not speak of two gods, we do not think of the unity of the Son with the Father in terms of the similarity of their teaching, but in terms of being (ousia) and reality. So we speak...of one God who exists as one form of divinity, like the relationship of light to its ray.De synodis, 52.1