Against Heretics (in 44 chapters, written from Rome), and of Irenaeus' Against Heresies (ca 180, in five volumes), written in Lyon after his return from a visit to Rome. The letters of Ignatius of Antioch and Polycarp of Smyrna to various churches warned against false teachers, and the Epistle of Barnabas accepted by many Christians as part of Scripture in the 2nd century, warned about mixing Judaism with Christianity, as did other writers, leading to decisions reached in the first ecumenical council, which was convoked by the Emperor Constantine at Nicaea in 325, in response to further disruptive polemical controversy within the Christian community, in that case Arianist disputes over the nature of the Trinity. Irenaeus ( – ) was the first to argue that his orthodox position was the same faith that Jesus gave to the apostles, and that the identity of the apostles, their successors, and the teachings of the same were all well-known public knowledge. This was therefore an early argument supported by apostolic succession. Irenaeus first established the doctrine of four gospels and no more, with the synoptic gospels interpreted in the light of John. Irenaeus' opponents, however, claimed to have received secret teachings from Jesus via other apostles which were not publicly known. Gnosticism is predicated on the existence of such hidden knowledge, but brief references to private teachings of Jesus have also survived in the canonic Scripture as did warning by the Christ that there would be false prophets or false teachers. Irenaeus' opponents also claimed that the wellsprings of divine inspiration were not dried up, which is the doctrine of continuing revelation. Late Antiquity (313–476) and Early Middle Ages (476–799) Christology The earliest controversies in Late Antiquity were generally Christological in nature, concerning the interpretation of Jesus' (eternal) divinity and humanity. In the 4th century, Arius and Arianism held that Jesus, while not merely mortal, was not eternally divine and was, therefore, of lesser status than God the Father. Arianism was condemned at the Council of Nicea (325), but nevertheless dominated most of the church for the greater part of the 4th century, often with the aid of Roman emperors who favoured them. Trinitarianism held that God the Father, God the Son, and the Holy Spirit were all strictly one being with three hypostases. The Euchites, a 4th-century antinomian sect from Macedonia held that the Threefold God transformed himself into a single hypostasis