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

That Church has an apostolic origin which was founded by the apostles. This indeed does not prevent that Church, as a universal society of the faithful, from containing very many particular churches which have arisen recently. Nay, particular churches could at first be founded either immediately by some one of the apostles or mediately through a disciple or successor of the apostles. Provided, therefore, that all and each of the parts of the Church are connected with the apostles either immediately or mediately, the whole Church is rightly called apostolic in origin. Now the necessity and the criterion of apostolic origin are to be shown.

1. The necessity of the apostolic origin of the Church of Christ does not need an elaborate proof. For although Christ is the proper author of the Church, nevertheless He founded it through the apostles, placed the apostles as its first teachers and rulers, and after His departure from the earth committed the Church to the apostles to be propagated and cared for. Therefore that Church which is not apostolic in origin is not the Church of Christ. Whence Paul also says that the faithful are built "upon the foundation of the apostles",¹ and the evangelist John describes the Church as a city having "twelve foundations, and in them the twelve names of the twelve apostles of the Lamb".² Likewise Tertullian: "The apostles … founded churches in every city, from which the other churches from then on borrowed the shoot of faith and the seeds of doctrine, and borrow them daily, that they may become churches. And by this very fact they themselves will be reckoned apostolic, as the offspring of apostolic churches. Every kind must be judged by its origin. And so those churches, so many and so great, are that one first Church from the apostles, from which all [come]. Thus all are first and all are apostolic, while all prove the one unity."³ Likewise St. Jerome warns that "one must remain in that Church which, founded by the apostles, endures even to this day".⁴ Then he adds: "From this very fact, that [the heretics] were instituted later, they show themselves to be those whom the apostle declared would come", namely deceivers. Therefore the true Church is necessarily apostolic in origin. But it is asked by what criterion one may distinguish the apostolic Church from the non-apostolic at first sight.

2. The criterion of apostolic origin is union with blessed Peter and his successor. For Christ built the whole Church upon Peter and his successors in the primacy as upon a foundation, by which all particular churches of all times receive firmness and unity. Whence already the apostles had to gather the particular churches, which they themselves founded immediately, around the Petrine center and insert them into the head of the whole Church. All the more, those particular churches which, in the course of time, were founded everywhere through disciples and successors of the apostles must remain intimately united with Peter and his successors. Therefore churches which are not organically united to the primatial see do not shine with apostolicity of origin, even if they bear the name of some apostle on their front; whereas churches which cultivate communion with the primatial see are truly apostolic, however recently they may have arisen. Apostolic origin is possessed by that universal Church alone, whole and entire, whose head and center is the primatial see of Peter.