APOSTOLICITY. — It is the last of the four notes of the Church proclaimed in the Nicene-Constantinopolitan Creed (v. CHURCH).
By saying that the Church is apostolic, it is intended to assert that it traces its origin to the apostles in what constitutes its essential constitution, and that it has remained identical from its beginnings to the present day. The apostolicity of the Church therefore implies its stability throughout the centuries: as the Church was in the time of the apostles, so it has remained without any “substantial” change, for there may be, and indeed there have been, accidental and developmental changes. The Church, indeed, the kingdom of God on earth, is like a mustard seed that grows into a great tree (Mt. 13:31-32) and, while remaining identical to itself in its essential features, grows like a living thing. It adapts itself to the times and places in the details of its legislation and social organization, thus manifesting the fecundity of the revealed deposit. The general and complete notion of apostolicity therefore means continuity with the Church founded by the Apostles through the uninterrupted succession of legitimate Shepherds (material apostolicity); and essential identity of ministry and hierarchical-monarchical governance (formal apostolicity).
The Fathers and theologians were led to emphasize certain points of particular importance in regard to controversy with heretics and schismatics, and from the earliest times an attempt was made to make apostolicity a distinctive note of the true Church against the innovating sects. Emphasis was therefore placed on: 1) the historical link that binds the ecclesiastical hierarchy to the apostles through ordination and the uninterrupted succession of bishops (apostolicity of origin); 2) the legitimacy of this succession, which is not such unless it has been directly, indirectly, or tacitly approved by the central authority established from the time of the apostles, proving that the Church had a primacy in the person of Peter, as is deduced from the texts of the New Testament, and that Peter had a successor in the Bishop of Rome, as attested by immediately sub-apostolic tradition. St. Irenaeus, for example, in the 2nd century, clearly stated that “every particular Church must be in agreement with the Church of Rome because of its superior authority.” Here is clearly indicated the regulating center of the unity of ecclesiastical communion and the legitimacy of mission, from which arises what is called the apostolicity of mission; 3) the identity of the doctrines of the present Church with the doctrine of the apostles, as it appears from the writings of the New Testament, from the tradition of the apostolic Fathers, and in general from the first centuries of Christianity, whence the apostolicity of doctrine; 4) the identity of the constitution and social structure of the present Church and the Church of apostolic times, whence the apostolicity of society, which can include the apostolicity of mission and doctrine as parts of the whole.
As is easily seen, apostolicity, considered as a property of the Church, goes beyond apostolicity considered as a note or distinctive sign of the true Church. Only elements that are sufficiently visible and apparent can serve as a note or distinctive sign, so that they can be verified by the average person who, faced with the churches currently in existence, wishes to ascertain which of them best reproduces the features of the primitive apostolic Church. These elements do not have the same probative value for all sects; effective against some, they are of no value against others. For example, to the early Fathers, such as St. Irenaeus, Tertullian, and St. Augustine, it sufficed to appeal to the apostolicity of origin to refute the heretics or schismatics of their time, whereas the same arguments would meet with far less success against the dissident Eastern Churches of our own day, to which one cannot deny the validity of their priesthood due to an uninterrupted succession of bishops, while they themselves claim to preserve the doctrine of the apostles contained in the books of the New Testament. Similarly, Catholic apologists, from the 16th century onward, have been able to demonstrate that Protestants possess none of the above-mentioned elements of apostolicity. But as soon as they have tried to use the same demonstration against the Greek-Russian Church, they have realized that their arguments lose their force, and that it is therefore necessary to reorganize the proofs and even the definition of the notes. The fact remains that many theologians no longer present apostolicity except as a negative note, i.e., as an element whose absence in a Church is sufficient to prove that it is false, but whose presence, at least in certain respects, is not sufficient to prove that it is the true Church.
It must be held, however, that at least one element of apostolicity can be given as a positive note, i.e., as belonging exclusively to the true Church: the apostolicity of mission, as we define it, i.e., in so far as it includes the primacy of Peter and of his successor, the Bishop of Rome, is a note that belongs exclusively to the Roman Catholic Church. But if this primacy is excluded, as some theologians do, it is no longer clear how the apostolicity of mission can constitute a property that meets the conditions of a positive note, as defined by most authors, since one of the conditions is precisely that the note can easily be known and verified. If one does not admit the existence, from the very beginning, of a mother Church to which particular Churches had necessarily to be attached, it will be very difficult to maintain that certain dissident Eastern Churches lack the apostolicity of mission. There is another method of identifying the true Church with the note of apostolicity, which consists in seeking among the various Churches now in existence that one which most closely resembles the Church of apostolic times and of the early Fathers. Given that Jesus Christ founded only one Church, the true one is that which has preserved the essential features of the primitive Church. It is by this method, which may be called one of comparison and transcendence, that Cardinal J. H. Newman (d. 1890) passed from Anglicanism to Catholicism. “All parties — he writes — are agreed that, among all existing systems, the present communion of Rome is in fact the image that most closely resembles the Church of the Fathers, free to believe, if one wishes, that one can get even closer on paper” (Letter to the Duke of Norfolk, *Difficulties of Anglicans*). By this method it is not denied that certain dissident groups do not possess elements of apostolicity, holiness, etc.; it is merely said that the Roman Catholic Church possesses these notes to a degree superior and transcendent to all others.