Bonus Saint of the Issue: Irenaeus of Lyon

On January 21, 2022, St. Irenaeus of Lyon became both the latest and most ancient Doctor of the Church, with Pope Francis bestowing on him the title Doctor unitatis. I had only learned of him the previous December and became enthralled with his towering legacy.

As a boy in second-century Smyrna, St. Irenaeus witnessed the preaching of the city’s bishop, St. Polycarp, who himself was personally trained and ordained by St. John. He grew up to become bishop of Lugdunum, now Lyon, and wrote several works defending Christian orthodoxy. His connection to St. Polycarp gave him heightened authority. This became, in part, the foundation for his appeal to apostolic succession and the living tradition. His death has conflicting accounts, but the Roman Martyrology favors his martyrdom. His tomb and relics were destroyed by Huguenots in 1562.

St. Irenaeus is most famous for his anti-Gnostic masterpiece Elenchus and Overturn of the Pseudonymous Gnosis, better known by its Latin title Against Heresies. The voluminous work exposes fallacies propagated by men like Valentinus, Marcion, and Cerinthus, asserting that their supposed secret knowledge was a distortion of scripture and true tradition. St. Irenaeus’ central intent was to maintain the doctrinal communion of the Church, which was becoming increasingly strained due to Gnostic defection.

However, St. Irenaeus also respected liturgical diversity, as can be seen in his involvement in the Quartodeciman Controversy (whether Easter should be tied to Passover, or always fall on a Sunday). Even though he observed Easter on Sunday, St. Irenaeus defended the Asian church from excommunication by citing how St. Polycarp learned quartodecimanism from St. John. He noted that the forty-day fast was more significant than the exact celebration date and that Pope St. Anicetus, himself a Sunday observer, still permitted St. Polycarp to continue his practice.

Only two of St. Irenaeus’ works survive entirely: Against Heresies and Epideixis of Apostolic Kerygma, a short catechetical work that directly references the former. The latter survives in a single Armenian translation discovered in 1904.

Now, why is he a Doctor of the Church? In Against Heresies, St. Irenaeus is the first recorded Christian to state several important traditions: that the serpent in Eden is Satan; that Luke and John were evangelists; that the gospels were written in the order Matthew, Mark, Luke, and John; that the four living creatures of Ezekiel and Revelation symbolize the evangelists; and the recapitulation theory of atonement. He is also the namesake of a “pressure makes diamonds” theodicy which says that suffering refines and completes man’s spiritual development. St. Irenaeus was already the patron saint of apologists and catechists.

Against Heresies is of considerable archeological value, too. For centuries before the recovery of the Nag Hammadi library, Against Heresies was the principal extant account of Gnostic beliefs. It is also an early witness to the authenticity of the Long Ending of Mark, Lk. 22:43-44, all thirteen Pauline epistles, the second epistle of John, and Revelation. It also excerpts two lost works, St. Justin Martyr’s Against Marcion and St. Papias’ Dominical Logion Exegesis. For a time, one fragment of Against Heresies quoting Matthew was the oldest extant New Testament text.

Now, not all of St. Irenaeus’ conjectures were sound; he was a literal millennialist and thought that Christ lived into his forties. In Against Heresies 4.6.1 he claims Mt. 11:27 appears verbatim in Mark, but there is no extant witness to this. In Epideixis, like several early Church Fathers, he seems to take the angelic view of Genesis 6:4’s “Elohim” literally. Yet, one cannot deny his importance as an early witness only twice removed from the apostles. He is “John’s spiritual grandson,” as Diane Severance, Ph.D, puts it. His overall legacy is of one working against schism, further ideologically uniting the East and West churches as a Greco-Roman bishop, hence his title Doctor unitatis. May his fervent example aid us in our own ecumenism.

St. Irenaeus, pray for us!