Gregory of Nyssa, the younger brother of Basil the Great. After being educated by Basil, he showed an inclination to become a teacher of eloquence, but by the influence of Gregory Nazianzen was prevailed upon to devote himself to the church. Though married, he was in 371 or 372 consecrated by Basil bishop of the little town of Nyssa, in Cappadocia. During the persecution of the adherents of the Nicene Creed in the reign of Valens, Gregory was, at the instigation of the governor of Pontus, deposed by a synod held in Galatia, on the pretext that he had wasted the church's goods. He made his escape, and after the death of Valens was joyfully welcomed back by his flock (378). He was present at the Council of Constantinople in 381, and (along with two other bishops) was appointed to the general oversight of the diocese of Pontus both by the council and by a decree of his friend Theodosius, by whom he had been called 'the common pillar of the church.' He travelled to Arabia and Jerusalem to set in order the churches there, and was again at a synod in Constantinople in 394. He must have died soon afterwards. Of the three Cappadocians Gregory was the greatest speculative theologian, the most faithful to Origenistic views, and not the least zealous defender of Nicene doctrine. He was a less able ruler than Basil, who sometimes lamented his untimely 'good nature' and 'simplicity.' His chief dogmatic work is his Twelve Books against Eunomius (the so-called 13th book is an independent work). Among his other works are treatises on the doctrine of the Trinity, including Antirrheticus (against Apollinaris) and an appeal To the Greeks, from 'common notions' (axioms), an attempt to establish the doctrine on grounds of abstract reason; a treatise On Destiny (against pagan fatalism); On the Soul and Resurrection (ed. Krabinger, Leip. 1837), in the form of a dialogue with his sister Makrina on her death-bed; several ascetic treatises, many sermons, and 23 epistles. In his great Catechetical Discourse (ed. Krabinger, Munich, 1838), which was written to convince educated heathens and Jews, he argues that the incarnation is the best possible form of redemption, as manifesting the four chief attributes of God—his omnipotence, mercy, wisdom, and justice. God alone is, and all turning away from God to the things of sense (things without being) is death. Christ did not assume a single human nature, but human nature itself in its entirety. 'His return from death is for the mortal race the beginning of their return to eternal life.' His incarnation is of cosmical significance, and extends to the whole spiritual creation, bringing the whole universe into harmony. 'Not only among men is he born man, but (with absolute consistency) coming also into being among angels he brings himself down to their nature' (Discourse on the Ascension of Christ). 'By this,' says Harnack, 'the incarnation is resolved into a necessary cosmical process; it becomes a special case of the omnipresence of the Deity in his creation. Alienation from God is as much included in the plan of the Kosmos as is restitution to him. Gregory helped to hand on to later times the pantheistic thought which he never himself conceived clearly and apart from the historical. There is a real kinship between him and the pantheistic Monophysites, the Areepagite, Scotus Erigena, and even the modern "liberal" theologians of Hegelian dye.'
His works were edited by Fronton du Duc (Paris, 1615; reprinted 1638), and more completely in Migne's Patrologia (series Græca, vols. xliv.-xlvi.). A beginning was made towards a good critical edition by G. H. Forbes (Burntisland, 1855) and Fr. Oehler (Halle, 1865). The latter has published a selection with a German translation (4 vols. Leip. 1858-59). See J. Rupp's monograph on Gregory (1834); H. Weiss, Die drei grossen Cappadocien (1872); and Harnack, Dogmengeschichte, vol. ii. (1888).