The early years of the Church are crowded with giants—St. Ambrose, St. John Chrysostom, St. Augustine, Tertullian, St. Jerome, St. Basil, St. Gregory of Nyssa and St. Gregory of Nazianzus—the list just keeps going on and on.
But who was the ‘first great theologian’?
It’s a name that’s probably not unfamiliar to contemporary Catholics who may recall that St. Irenaeus took on the Gnostics and other heretics in his aptly titled work, Against Heresies. In fighting against one of the earliest heresies, he demonstrated the existence of an orthodoxy and a church hierarchy willing to enforce it. In terms of sheer chronology, he arrives on the scene as the first great theologian of the Church—a fact that lends some additional weight to his statements on the Eucharist, Mary and salvation, Rome and Church authority. Given his place in the timeline of early Church history—Irenaeus derived much of his theology from Polycarp, a student of the Apostle John, and Irenaeus, in turn, influenced St. Ambrose, who converted St. Augustine—it seems hard to overstate his theological importance.
It’s clear to anyone who’s reading Irenaeus honestly that already in the second century AD, he had a fully developed understanding of the Real Presence, even though he did not use that term; that the basic outline of Catholic Mariology was already present in his writings; and that the primacy of Rome was already fixed in the early Christian consciousness. His statements on such issues argue compellingly against the Protestant stereotype that they were the concoctions of a corrupt medieval Catholicism.
Below are links to some key excerpts on these topics:
■ The Eucharist: It’s clear from reading excerpts, such as the ones here and here, that St. Irenaeus had a clear idea of the doctrine of the Real Presence—and he draws what he sees as a vital connection to the resurrection. According to Irenaeus, it is only by truly eating the Body and Blood of Christ, that we can be assured that we will also partake in the resurrection.
■ Authority of Rome: Irenaeus speaks of a “tradition derived from the apostles, of the very great, the very ancient, and universally known Church founded and organized at Rome by the two most glorious apostles, Peter and Paul … which comes down to our time by means of the successions of the bishops. For it is a matter of necessity that every Church should agree with this Church, on account of its preeminent authority, that is, the faithful everywhere, inasmuch as the tradition has been preserved continuously by those who exist everywhere.” No question here about the primacy of Rome or the beginnings of the Petrine office.
■ The New Testament Canon: Irenaeus is also a key source for the early New Testament canon. Click here for more about his importance in this area.