Gregory of Nyssa

Gregory was a younger brother of Basil of Caesarea and Macrina. He says in his memoir of his sister that for a long time he could not visit her because the leaders of the opposing party kept driving him out of his own country (Gregory of Nyssa, Life of Macrina p. 41 (PG 46.976)). In the short work On Not Three Gods he argues that Father, Son and Spirit are one God because their action is one, the persons being distinguished only as cause and caused (Gregory of Nyssa, On Not Three Gods).

The law of 381 by which Theodosius handed the churches to the Nicene bishops names him, with the bishops of Caesarea and Melitene, as one of those with whom bishops of the region of Pontus must be in communion (Theodosian Code 16.1.3), and Socrates records the same arrangement among the decisions of the council of Constantinople in that year (Socrates, Church History 5.8). Jerome heard him read from his work against Eunomius and says that he was still writing in 392–393 (Jerome, On Illustrious Men 128). See the Cappadocians and the Doctrine of the Trinity.