Many people are of the opinion that Irenaeus considers the church at Rome to be a kind of standard of orthodoxy in Christian theology. Here is the controverted sentence:
Ad hanc enim ecclesiam propter potiorem principalitatem necesse est omnem convenire ecclesiam, hoc est, eos qui sunt undique fideles, in qua semper ab his, qui sunt undique, conservata est ea quae est ab apostolis traditio.Irenaeus, Against Heresies 3.3.2
What does this sentence mean? How to translate it? Here is a possible rendering:
With this church, indeed, on account of its greater preeminence, it is necessary that every church agree, that is, those who are faithful everywhere, in [each] which [church] by these who are everywhere the tradition that comes from the apostles has been preserved.
What does Irenaeus mean when he says that it is “necessary” that every church agree with the Roman church?
There is certainly no need to think that there is anything about the theology of the Roman church simply as such that is especially normative or authoritative. There is no idea of Roman “primacy” in Irenaeus, nor is the “necessity” at stake a matter of theological principle valid for all times. This can be shown as follows.
Irenaeus’s purpose in context is to show that the purportedly apostolic teachings of the Gnostics are not in fact apostolic. To this end, he proposes to consider teachings of the various churches founded by apostles themselves. In these churches, it is possible to name who has been a bishop from the time of apostles until the present day. And all these persons, Irenaeus says, “neither taught nor knew of anything like what these [heretics] rave about” (3.3.1). This suffices in Irenaeus’s mind to show that the Gnostic doctrines are not in fact apostolic.
At the same time, Irenaeus says that “it would be very tedious, in such a volume as this, to reckon up the successions of all the Churches” (3.3.2). He therefore considers it sufficient to mention only the example 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”. And it is with such a preface that he says what is quoted above: “With this church, indeed, on account of its greater preeminence, it is necessary that every church agree, etc.”
What then is the nature of this “necessity” to which Irenaeus appeals? It is clearly a conditional and inferential one. It is “necessary” that every apostolic church agree with the church at Rome given the actual fact that they all hold it in such high esteem. Put another way, the reputation of the Roman church among all the other apostolic churches means that it would be superfluous for Irenaeus to draw up the lists of bishops from all these other churches. The church at Rome would not have such a reputation among all the apostolic churches “in which … the tradition that comes from the apostles has been preserved” if they did not equally judge its doctrine to be apostolic. They have to agree with it if they respect it so. That is why citing only the example of the Roman church suffices.
It is also worth noting here that Irenaeus appears to be convinced that the apostolicity of these other churches can also be determined independently of the church of Rome. Otherwise, their esteem and agreement with the theology of the Roman church would be irrelevant for his point. That they respect the Roman doctrine as apostolic would not prove anything if the doctrine of these other churches could not be shown to be apostolic independently of their attitudes about Rome. This is why, once more, given Irenaeus’s purposes, it suffices to enumerate the list of the Roman bishops alone, without mentioning every other church founded by an apostle.
On the other hand, there is nothing in Irenaeus’s text that demands or even motivates interpreting this “necessity” as being of an absolute sort, as though it were a principle for theology at all times that every church should agree with the theology of the church at Rome. To begin, he already admits that the bishops of any of the churches founded by the apostles could err and make mistakes just before this: “For [the apostles] were desirous that these men [i.e., the bishops] should be very perfect and blameless in all things, whom also they were leaving behind as their successors, delivering up their own place of government to these men; which men, … if they should fall away, [would bring] the direst calamity” (3.3.1). There is consequently no reason why Irenaeus would admit that the bishops of the Roman church simply as such are a standard for theology at all times. It also goes without saying that Irenaeus makes no mention of any fine distinctions between official and unofficial teachings of the Roman bishops, such as Roman Catholic theology would make in later days.
There is also this further point to make. Irenaeus would be entirely unconvincing against his opponents if he were to be proposing such a thing as “Roman primacy.” The heretics themselves do not grant that one must agree with the theology of the church of Rome. After all, they disagree with it. Why, then, should he be appealing to such a notion in order to prove that their doctrine is not genuinely apostolic? On what basis? He would be begging the question against them. He would also be offering an extremely poor argument, insofar as nothing that he says at AH 3.3 offers any kind of justification for the pretense of Roman primacy. On the other hand, Irenaeus would be much more convincing against the heretics if he were suggesting that the theology of the church of Rome is representative of the theology of the apostles insofar as all the apostolic churches hold it in such high esteem. But this would mean that there is nothing special about the Roman church simply as such.
What then is Ireaneus’s opinion about the Roman church? It has a “greater preeminence” (potiorem principalitatem) in the specific sense that it is renowned and esteemed among all the apostolic churches throughout the world in which the apostolic tradition has been preserved. This is an indication of their agreement with its theology. This also presupposes that the apostolicity of the doctrine of these other churches can be determined apart from appeal to the Roman church. Otherwise the fact of their agreement with Rome would not prove that Rome’s doctrine is apostolic. For these reasons, it suffices for Irenaeus’s dialectical purposes in context to appeal only to its teachers in order to show that the Gnostic doctrines are not genuinely apostolic. But there is nothing particularly special about the Roman church simply as such.