Bishop of Lyons in Gaul from about 180 CE; a champion of orthodoxy against the Gnostics, emphasizing the continuity of the Christian revelation with the Old Testament. Irenaeus was the first Church leader to set out a canon of the NT scripture (the four gospels, Acts, and the epistles of Paul) as authoritative alongside the OT, which could be interpreted allegorically. These principles were a foundation for genuine biblical scholarship.