Apologeticae sive Theologiae Fundamentalis, Tomus II (Pars Altera): Demonstratio Catholica

That Church enjoys apostolic succession which the apostles continuously govern in their successors, or whose pastors have been substituted for the apostles in a never-interrupted series and by legitimate commission. It is said: in a never-interrupted series, namely because, once the connection with the apostles has at some time been interrupted, the apostolic power of governing the Church does not revive again. It is added: by legitimate commission, because the merely material occupation of a pastoral see does not suffice, but a formal transmission of apostolic power is required, made by him who has this power and is able to commit it. For apostolic succession understood in this way, its necessity and its criterion must again be demonstrated.

1. Necessity of apostolic succession. Christ laid down the law of apostolic succession by that very fact that He decreed that the pastoral office handed to the apostles should perdure in their successors. For it is evident that it cannot perdure except by apostolic succession. Whence the apostles communicated the hierarchical governance of the churches to others by election and the imposition of hands, and prescribed the same law of a never-interrupted and legitimate succession to be observed also by their disciples, as we have seen elsewhere.¹ The most ancient Fathers always insist on apostolic succession and use it as a mark of the true Church against heretics. St. Irenaeus writes in this sense: "It is necessary to obey the presbyters who are in the Church, those who have succession from the apostles, as we have shown, who together with the succession of the episcopate have received the sure charism of truth according to the good pleasure of the Father; but the rest, who stand apart from the principal succession and gather in whatever place, are to be held as suspects, either as heretics and of evil mind, or as schismatics, elated and self-pleasing … But all these have fallen from the truth."² Tertullian urges the heretics: "Let them therefore produce the origins of their churches, let them unfold the order of their bishops, running down by succession from the beginning in such a way that that first bishop had as author and predecessor some one of the apostles or of apostolic men, who nevertheless persevered with the apostles. For in this way the apostolic churches report their registers."³ St. Cyprian declares: "Novatian is not in the Church, nor can he be counted a bishop, who, despising the evangelical and apostolic tradition, succeeding no one, has arisen from himself."⁴ By the apostolic succession of pastors, therefore, the true Church is denoted. It remains that we establish the criterion by which today the apostolic succession of pastors can be discerned.

2. The criterion of apostolic succession is again the connection with the successor of Peter in the primatial see. Theoretically, indeed, the apostolic succession of the individual churches can be demonstrated in a twofold way, namely, either by enumerating all the bishops who have presided over those churches in a never-interrupted and legitimate series from the apostolic age, or by simply appealing to the apostolic succession of the Roman Church, into which the other churches are organically inserted. In practice, however, we can proceed only by this latter way, as St. Irenaeus already showed. For, speaking of the apostolicity of doctrine, to be discerned from apostolic succession, he says: "It is possible for all who wish to see the truth to contemplate the tradition of the apostles manifested in the whole world in every church. And we can count up those who were instituted bishops by the apostles and their successors down to us … But since it is very long … to enumerate the successions of all the churches, pointing to that greatest and most ancient and known to all church, founded and constituted at Rome by the two most glorious apostles Peter and Paul, and indicating the tradition which it has from the apostles and the faith announced to men, coming down to us through the successions of bishops, we confound all those who in any way … gather otherwise than is fitting. For to this church, on account of its more powerful principality, it is necessary that every church, that is, the faithful who are from everywhere, agree, in which always, by those who are from everywhere, the tradition which is from the apostles has been preserved … By this ordination and succession, the tradition which is from the apostles in the church and the proclamation of the truth has come down to us. And this is the fullest demonstration, that one and the same life-giving faith has been preserved in the church from the apostles until now and handed on in the truth."⁵

But if already in the second century Irenaeus judged that one must appeal to the apostolic succession of the Roman Church alone, how much more in the twentieth century? For today it is not only "very long to enumerate the successions of all the churches", but rather this is altogether impossible. For apart from the Roman, no other church any longer enjoys immediately apostolic succession. Whence the other churches can be proved apostolic by the Roman see alone.⁶ The never-interrupted and legitimate succession of the Roman bishops from the apostles down to us, however, is historically easy to know in such a way that it is conceded by all. And since the Roman Church is the center and head of all the churches, all bishops who are sent by the Roman successor of Peter and communicate with him are joined to the apostolic college instituted by Christ. Therefore, since the ultimate criterion both of the origin and of the apostolic succession is the connection with Peter and his successor, it must simply be said that that Church is apostolic whose head and center is the see of Peter. Whence most truly St. Ambrose: "Where Peter is, there is the Church."⁷