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Irenaeus, Doctor of Unity

Here's what it means to be a Doctor of the Church, and why St. Irenaeus deserves the honor

Early this month, Pope Francis announced that he will soon name the second-century saint Irenaeus of Lyon as a Doctor of the Church. This announcement comes after news that the bishops of France and the United States had petitioned the Vatican to give Irenaeus this title. So what does it mean to call someone a Doctor of the Church, and why does Irenaeus deserve this epithet?

It may sound odd to modern ears, but the original meaning of the word doctor is “religious teacher, adviser, scholar.” Calling Irenaeus a doctor (or “teacher”) of the universal Church is a way of recognizing his theological contributions. As Pope St John Paul II explains:

Indeed, when the Magisterium proclaims someone a Doctor of the Church, it intends to point out to all the faithful, particularly to those who perform in the Church the fundamental service of preaching or who undertake the delicate task of theological teaching and research, that the doctrine professed and proclaimed by a certain person can be a reference point, not only because it conforms to revealed truth, but also because it sheds new light on the mysteries of the faith, a deeper understanding of Christ’s mystery.

Becoming a Doctor of the Church thus requires both personal holiness (only canonized saints may be declared Doctors) and what the Church calls eminent doctrine—that is, grasping “the very heart of the message of revelation in a fresh and original vision, presenting a teaching of eminent quality.” That doesn’t mean inventing “diverse and strange teachings” (Heb. 13:9), of course. Rather, these are people who live out the Christian call to “contend for the faith which was once for all delivered to the saints” (Jude 1:3), by presenting these perennial truths in new and compelling ways.

Irenaeus, who lived from roughly 130 to 203, is chiefly remembered for his treatise Against Heresies, in which he defends the Catholic faith from the attacks of Gnosticism and Marcionitism. By the standards of the second century, it’s a massive work, running over 250 pages in Roberts and Donaldson’s translation. (By comparison, Pope St. Clement’s famous letter to the Corinthians is about 16 pages.) In it, Irenaeus offers “a closely argued reading of a range of Gnostic texts which demonstrates that it was his Gnostic opponents who, in claiming access to a body of esoteric knowledge available only to a spiritual elite, produced a series of speculative spiritual systems devoid of evidential grounds and reasoned arguments.” In other words, he took the trouble to understand what his opponents believed, to lay out their arguments, and then to pick those arguments apart. Prior to the discovery of a library of Gnostic texts in Nag Hammadi in 1945, his writings were the primary way by which we knew what Gnostics believed.

But Irenaeus didn’t just rebut bad theology; he also laid out good theology. He made lasting contributions to our understanding of the unique role of the Virgin Mary in God’s plan of salvation (for “it was that the knot of Eve’s disobedience was loosed by the obedience of Mary. For what the virgin Eve had bound fast through unbelief, this did the Virgin Mary set free through faith”), is the earliest existing witness to the authorship of the four Gospels, and provides one of the first trinitarian creeds, calling it “the rule of our faith, and the foundation of the building.” Irenaeus remains one of the most cited theologians in the Catechism, where he is referenced some twenty-nine times.

His legacy is not only one of orthodoxy and thoroughness, but also of gentleness. His name comes from the Greek word for peace and unity (eiréné), and Francis has chosen the title Doctor Unitatis (“doctor of unity”) for Irenaeus. When Francis’s predecessor Pope Victor I wanted to excommunicate all of the churches of Asia Minor for celebrating Easter on the wrong day, it was Irenaeus who convinced him to relent. As a bishop of what’s now Lyon, France, Irenaeus followed the Roman custom of celebrating Easter on Sunday. But he had grown up in the East, in Asia Minor, and so he knew that tying the dating of Easter to Passover was a practice instituted in those churches by the apostle John himself. With a foot in each world, Irenaeus was in a unique position to serve as a sort of mediator.

And so, as Eusebius recounts, Irenaeus “maintained that the mystery of the resurrection of the Lord should be observed only on the Lord’s day. He fittingly admonishes Victor that he should not cut off whole churches of God which observed the tradition of an ancient custom.” In other words, he conceded that the pope was right on the substance (Easter should be celebrated on Sunday) but also criticized him for overreacting, reminding him that earlier Christians were able to “live in peace with one another” despite their differing liturgical practices. Victor seems to have been convinced by Irenaeus’s entreaties, and Eusebius writes that “Irenaeus, who truly was well named, became a peacemaker in this matter, exhorting and negotiating in this way in behalf of the peace of the churches.” In an age in which Catholics are often guilty of thinking the worst of one another (including over liturgical matters), he’s a much-needed teacher today.

Having said all of this, I can understand why the creation of a new Doctor of the Church may be met with some resistance. Until 1568, the Church officially honored only four saints as Doctors: Ss. Ambrose, Augustine, Gregory the Great, and Jerome. Pope St. Pius V changed this by adding four Eastern Church Fathers—Ss. John Chrysostom, Basil, Gregory Nazianzus, and Athanasius—as well as St. Thomas Aquinas, and today, some thirty-six saints are honored with the title Doctor.

Some Catholics are annoyed at this lengthening of the list. Fr. Dominic Savoie, FSSP calls it an “equivocation” to speak of later Doctors (even Aquinas!) as Doctors, since they are “a class which stands upon the shoulders of the great four.” That’s an understandable critique, but those “great four” themselves stood on the shoulders of those who came before them, including Irenaeus. In fact, in Against Julian, Augustine refers to Irenaeus as one of the “memorable doctors” of old, who are “famous and brilliant holy teachers of the Catholic truth,” and to whom he appeals to rebut the heresy of Pelagianism. In other words, Irenaeus was early (and brilliant) enough to be a Church Father even to other Church Fathers.

Ironically, the whole idea of later saints and theologians standing on the shoulders of earlier ones is one first articulated by . . . Irenaeus.  He was a student of St. Polycarp, who was a disciple of the apostle John. When another of Polycarp’s students, a man by the name of Florinus, became a Gnostic, Irenaeus wrote to him, saying, “These doctrines, O Florinus, to speak mildly, are not of sound judgment. These doctrines disagree with the Church, and drive into the greatest impiety those who accept them.” Irenaeus can rebuke him with authority because they both learned from Polycarp, and “I am able to bear witness before God that if that blessed and apostolic presbyter had heard any such thing [as Gnosticism], he would have cried out, and stopped his ears, and as was his custom, would have exclaimed, ‘O good God, unto what times hast thou spared me that I should endure these things?’” It’s for this same reason that Irenaeus traces the succession of each bishop of Rome. He explained that since “it is a matter of necessity that every church should agree with this church on account of its preeminent authority,” one way of refuting Gnosticism was to show that neither Ss. Peter and Paul, nor any of the popes succeeding them, knew of these strange doctrines.

In short, it’s hard to overstate Irenaeus’s theological contributions to the Church, nor our need for him as a model of orthodoxy, traditionalism, and charitable engagement, which is why we should rejoice today that he’s going to be named a Church Doctor. St. Irenaeus, pray for us!

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