Irenaeus, Against Heresies

Irenaeus was born in Smyrna around AD 130 and as a boy heard the aged Polycarp preach — Polycarp himself a disciple of John the Apostle. Irenaeus later traveled to Rome to study, and by 177 he was a presbyter of the church at Lyon (Lugdunum) in Roman Gaul. The same year a violent local persecution killed Bishop Pothinus and dozens of others; Irenaeus, providentially absent on a mission to Rome bearing letters from the Lyon martyrs, returned to succeed Pothinus as bishop. He composed his five-volume Adversus Haereses ("Against Heresies") around AD 180, originally in Greek, to refute the Gnostic teachings of Valentinus, Marcion, and their followers. The work survives complete only in Latin translation, with substantial Greek fragments preserved in Hippolytus and Epiphanius. Books 1-2 catalog and refute the Gnostic systems; Books 3-5 set out the apostolic faith Irenaeus received. He names the four canonical Gospels — Matthew, Mark, Luke, John — and famously argues, on a numerological theological logic, that there can be only four: as there are four winds, four corners of the earth, and four living creatures around the throne. The argument is unconvincing as a proof; it is decisive as a witness that, by 180, the four-Gospel canon was a settled fact in the West. Irenaeus also preserves the chain of teaching he had personally inherited — John to Polycarp to himself — and quotes extensively from earlier Christian writings, including Justin Martyr, Papias, and 1 Clement. He died around AD 202, possibly during the persecution under Septimius Severus, though the tradition of his martyrdom is late. Sources: Irenaeus, Adversus Haereses (ANF vol. 1; SC editions 1965-1982); Denis Minns, Irenaeus: An Introduction (2010); Robert M. Grant, Irenaeus of Lyons (1997); Eric Osborn, Irenaeus of Lyons (2001).