The Feast of St. Hilary of Poitiers
known as "the Athanasius of the West" is today. Information on him can be found here.
"Catholic theologians met this difficulty, both before and after the Nicene Council, by insisting on the unity of origin, which they taught as existing in the Divine Triad, the Son and Spirit having a communicated divinity from the Father, and a personal unity with Him; the Three Persons being internal to the Divine Essence, unlike the polytheism of the Greeks and Romans, the tritheism of Marcion and the Manichees, and the Archical Hypostases of Plotinus. Thus Hippolytus says: "I say, 'Another,' not two Gods, but as light from light, as water from a spring, or a ray from the sun." And Hilary, in the fourth century, confirms him, saying, "The Father does not lose His attribute of being the One God, because the Son also is God, for the Son is God from God, One from One, therefore One God, because God from Himself." De Trin. iv. 15. "- Venerable John Henry Newman, C.O., Tracts Theological and Ecclesiastical