Gregory of Nyssa Saint (335–98), Greek theologian and mystic who tried to reconcile Platonism with Christianity. As bishop of Cappadocia in eastern Asia Minor, he championed orthodoxy and was prominent at the First Council of Constantinople. He related the doctrine of the Trinity to Plato’s ideas of the One and the Many. He followed Origen in believing that man’s material nature was due to the fall and in believing in the Apocatastasis, the universal restoration of all souls, including Satan’s, in the kingdom of God. See also APOCATASTASIS, ORIGEN. L.P.P.