St. Irenaeus of Lyons: Doctor of Unity or Doctor of Division?
Taking a look at St. Irenaeus' writings and the history of their use
In October 2021, Pope Francis leaked his intention of declaring St. Irenaeus of Lyons a Doctor of the Catholic Church. It is a special honor given to those in the Catholic Church who have notably contributed to the development of Catholic doctrine. On January 20th, 2022, “Cardinal Marcello Semeraro, prefect of the Congregation for Saints' Causes, asked the pope to "accept the affirmative opinion" of the cardinals and bishops who are congregation members to confer the title on the second-century theologian known for his defense of orthodoxy amid the rise of Gnostic sects.”
Many Doctors of the Church are given ‘special’ titles that explain the overall theme of their contribution to the teaching of the Catholic Church. For example, St. Augustine is the Doctor of Grace because of his development of the role of grace in his writings against the Pelagians. St. Thomas Aquinas is known as the Angelic Doctor for his work on Angels. The America magazine article quotes Pope Francis explaining what St. Irenaeus’ theme and title will be declared, “Your patron, St. Irenaeus of Lyon — whom I will soon declare a doctor of the church with the title, 'doctor unitatis' ('doctor of unity') — came from the East, exercised his episcopal ministry in the West, and was a great spiritual and theological bridge between Eastern and Western Christians,"
I remember reading about this back in October. The fact that St. Irenaeus was named a Doctor of the Church didn’t really surprise me at the time, what surprised me at the time was the theme or title that was going to be given to St. Irenaeus—the Doctor of Unity. In October, I happened to be finishing my last class for my Master’s in Theology, which was Patristics. I thought to myself, “Well, St. Irenaeus does write on themes of unity, but the historical perception of St. Irenaeus is anything and everything but unitive.”
The first point, specifically on St. Irenaeus’ writings with the theme of Christian unity, I listened to a Word on Fire podcast with Bishop Barron around the same time in October when Pope Francis revealed his intent on declaring St. Irenaeus Doctor of the Church. During the podcast, Bishop Barron expressed his surprise when it had been recommended by the French bishops that St. Irenaeus be named a Doctor of the Church. I do not recall the details of the podcast, but I remember Bishop Barron’s surprise in which he thought St. Irenaeus should already be a Doctor of the Church, and that he wasn’t. The fact of Barron’s surprise does indicate a rise of St. Irenaeus’ stature during the formative seminary years of Bishop Barron, which will be explained below. Notwithstanding, both Pope Francis’ and Bishop Barron’s conclusion does have historical pedigree within Iraeneus’ own words, but the fact remains that his reputation suffered for much of Church history and would not be rehabilitated until the 20th century, so what caused this diminishment of St. Irenaeus’ influence?
So, defending Bishop Barron’s (And Pope Francis’) opinion on St. Irenaeus as being valid, there is certainly reason to declare St. Irenaeus of Lyons—the Doctor of Unity. The very beginning of St. Irenaeus’ work Against Heresies acknowledges the diversity of Christian communities dispersed across the known world and their unity of faith “received from the Apostles and from their disciples the faith in one God.” Furthermore, St. Irenaeus continues to explain the role of the Church as a single entity which “the Church, having received this preaching and this faith, although she is disseminated throughout the whole world, yet guarded it, as if she occupied but one house.” 
There are two texts found in the Gospel of John that speaks to the unity of the house (Jn. 17:21) and the diversity of rooms found in the Father’s house (Jn. 14:2), so there may be room for such things as church disciplines, inculturation, liturgical rites, etc., but as St. Irenaeus understands it, the unity of the faith should be centered on such things as the articles of faiths—the traditions, “For, while the languages of the world are diverse, nevertheless, the authority of the tradition is one and the same.” 
St. Irenaeus; after explaining disagreements on tradition, teaching, and the pedigree of Sacred Scripture, appeals to the importance of Rome being the final arbiter of debates and defense of the faith. Irenaeus writes, “by pointing out here the successions of the bishops of the greatest and most ancient Church known to all, founded and organized at Rome by the two most glorious Apostles, Peter and Paul, that Church which has the tradition and the faith which comes down to us after having been announced to men by the Apostles. For with this Church, because of its superior origin… In the time of Clement, no small dissension having arisen among the brethren in Corinth, the Church in Rome sent a very strong letter to the Corinthians, exhorting them to peace and renewing their faith.…”
St. Irenaeus appeals to the well-established consensus of the apostolic origin of the Church of Rome. What is important point about this appeal to the consensus is that St. Irenaeus’ assertion is still within the living memory of the Apostolic church. The expressed assertion of Peter being in Rome and the establishment and importance of the Church in Rome could have been challenged during the period if St. Irenaeus erred in some manner.
So, it looks like the case is closed for St. Irenaeus being the Doctor of Unity in the Catholic Church, right?
One of the best classes I ever took during my time as an undergraduate in history with one of my favorite professors was called The Historian’s Craft—basically a Historiography 101 class. Historiography is the study of how history is written by historians, or another simple explanation is the study of biases of historians and their schools of thought in the hope of discovering objectivity in the field of history.
So, what does the historiography say about St. Irenaeus of Lyons and his role in Christian unity? How did people use the writings of St. Irenaeus in their own work? Most theologians in whatever form from the Early Christian Church (in which St. Irenaeus was well-read) to the Reformation to modern theologians noticed one thing about St. Irenaeus’ writings—he was ambiguous or imprecise in his theological language—any theologian, sect, or group could take the writings of St. Irenaeus and attach them to their cause. The motive of enlisting St. Irenaeus was desirable because of his proximity to the history of the early Christian church, which gave his words authority.
St. Irenaeus’ influence as the Church progressed began to diminish largely because he could be used as a source for polemical disagreements with both sides being able to use his imprecise language as Minis explains that Irenaeus “expressed his own views in language that was considerably more plastic than that of later generations, he is quoted with approval by advocates on both sides of disputed questions particularly with regard to Christology and the Eucharist.” Due to this malleable language, it’s no surprise that during the Reformation, Irenaeus was used for polemical purposes. Irenaeus unclear language allowed for Christological ambiguities with the Son being ‘mixed’ not united to the Word of God. Irenaeus also makes no mention of purgatory but advocated for free will, which Erasmus used against Martin Luther. The Lutherans would then enlist St. Irenaeus’ authority to help their cause of communion under both kinds.
The historiographical record of Christian polemics shows that St. Irenaeus was used authoritatively when he was useful and disregarded when convenient with such topics as Mary, the mother of God. Protestants would begin to assert that any writings from St. Irenaeus that suggested too Catholic doctrine were interpolations and not the true works of the Church Father. In fact, the interpolation assertion would be used in the 18th century with Johan Salomo Semler calling into question Irenaeus’ authorship of Against Heresies because it was too Roman. The interpolation argument in various forms would continue into the 19th century until finally in the 20th century, St. Irenaeus was accepted by the consensus of the academy. It was during the Vatican II council, in which a revival of St. Irenaeus’ thought would occur as he was found being quoted on topics that ranged through the history of the Church on the Eucharist, Mary, and Christology. No doubt, it was this revival during the council which trickled down to seminaries shortly after that influenced both Bishop Barron’s and Pope Francis’ views on newest to be named Doctor of the Church.
So, the question that must be asked regarding St. Irenaeus assent to being named The Doctor of Unity, can theologians interpret St. Irenaeus’ work as unifying in quality, or does the historiographical record show that historically St. Irenaeus’ work has sowed more division than Christian unity?
Please comment below your thoughts.
 Esteves, J., 2022. Pope Francis receives recommendation to declare St. Irenaeus a doctor of the church. [online] America Magazine. Available at: <https://www.americamagazine.org/faith/2022/01/20/saint-irenaeus-doctor-church-pope-francis-242240> [Accessed 20 January 2022].
 Esteves, 2022
 St. Irenaeus, “Against Heresies.” W. A. Jurgens, tran., The Faith of the Early Fathers, vol. 1 (Collegeville, MN: The Liturgical Press, 1970–1979), 84.
 Ibid, 85.
 Ibid, 90.
 Denis Minns. “Irenaeus of Lyons.” ed. Ken Parry, The Wiley Blackwell Companion to Patristics (Oxford: John Wiley & Sons, 2019), 73.
 Ibid, 78.
 Ibid, 81.