the assembling, under the auspices of _Constantine_, of the _Council of Nicaea_ (A.D. 325), the first of a series of General Councils, for the adjudication of doctrinal disputes, that were held in this and the following centuries. The Arian doctrine was condemned at Nicaea, and, after a long contest in the period subsequent, was finally determined to be heretical. In the West, the main controversy was that raised by _Pelagius_, respecting the power of the will, the native character of men, and the agency of God in their conversion. In this debate, _Augustine_ (354-430), the most eminent theologian of the West, bishop of _Hippo_ in North Africa, was the renowned champion of the doctrine of _grace_ against what he considered an exaggerated assertion of _free-will_. Pelagianism was condemned in the West, and nominally in the East where views intermediate between the Pelagians and Augustinians commonly prevailed. The most eminent scholar contemporary with Augustine was _Jerome_, who died in 420, the author of the Latin version of the Scriptures, called the _Vulgate_. Preceding Augustine in North Africa, early in the third century, was _Tertullian_, a vigorous and fervid writer, who first made Latin the vehicle of theological discussion; and, a little later, _Cyprian_, whose works relate chiefly to church unity and hierarchical government, of which he was a devoted champion. Late in the second century, _Irenaeus_, bishop of Lyons in Gaul, one of the most eminent ecclesiastics of that day, composed an elaborate work against the Gnostic heresies. _Irenaeus_ had known _Polycarp_, a disciple of John the apostle.