St. Vincent of Lerins and tradition
The famous dictum of St. Vincent of Lerins was characteristic of the attitude of the Ancient Church in the matters of faith: "We must hold what has been believed everywhere, always, and by all" [Commonitorium, 2]. This was at once the criterion and the norm. The crucial emphasis was here on the permanence of Christian teaching. St. Vincent was actually appealing to the double "ecumenicity" of Christian faith — in space and in time. In fact, it was the same great vision which had inspired St. Irenaeus in his own time: the One Church, expanded and scattered in the whole world, and yet speaking with one voice, holding the same faith everywhere, as it had been handed down by the blessed Apostles and preserved by the succession of witnesses: quae est ab apostolis, quae per successionem presbyterorum in ecclesiis custoditur. ["Which is being preserved in the Church from the Apostles through the succession of the presbyters."] These two aspects of faith, or rather — the two dimensions, could never be separated from each other. Universitas and antiquitas, as well as consensio, belonged together. Neither was an adequate criterion by itself. "Antiquity" as such was not yet a sufficient warrant of truth, unless a comprehensive consensus of the "ancients" could be satisfactorily demonstrated. And consensio as such was not conclusive, unless it could be traced back continuously to Apostolic origins. Now, suggested St. Vincent, the true faith could be recognized by a double recourse — to Scripture and Tradition: duplici modo … primum scilicet divinae legis auctoritate, tum deinde ecclesiae catholicae traditione. ["In two ways … first clearly by the authority of the Holy Scriptures, then by the tradition of the Catholic Church."] This did not imply, however, that there were two sources of Christian doctrine. Indeed, the rule, or canon, of Scripture was "perfect" and "self-sufficient" — ad omnia satis superque sufficiat. ["For all things complete and more than sufficient."] Why then should it be supplemented by any other "authority"? Why was it imperative to invoke also the authority of "ecclesiastical understanding" — ecclesiasticae intelligentiae auctoritas? The reason was obvious: Scriptures were differently interpreted by individuals: ut paene quot hominess tot illinc sententiae erui posse videantur. ["So that one might almost gain the impression that it can yield as many different meanings, as there are men."] To this variety of "private" opinions St. Vincent opposes the "common" mind of the Church, the mind of the Church Catholic: ut propheticae et apostolicae interpretationis linea secundum ecclesiastici et catholici sensus normam dirigatur. ["That the trend of the interpretation of the prophets and the apostolic writings be directed in accordance with the rule of the ecclesiastical and Catholic meaning."] Tradition was not, according to St. Vincent, an independent instance, nor was it a complementary source of faith. "Ecclesiastical understanding" could not add anything to the Scripture. But it was the only means to ascertain and to disclose the true meaning of Scripture. Tradition was, in fact, the authentic interpretation of Scripture. And in this sense it was co-extensive with Scripture. Tradition was actually "Scripture rightly understood." And Scripture was for St. Vincent the only, primary and ultimate, canon of Christian truth (Commonitorium, cap. II, cf. cap. 28).

The hermeneutical question in the Ancient Church
At this point St. Vincent was in full agreement with the established tradition. In the admirable phrase of St. Hilary of Poitiers, scripturae enim non in legendo sunt, sed in intelligendo. ["For Scripture is not in the reading, but in the understanding;" ad Constantium Aug., lib. II, cap. 9, ML X, 570; the phrase is repeated also by St. Jerome, Dial. c. Lucifer., cap. 28, ML XXIII, 190-191]. The problem of right exegesis was still a burning issue in the Fourth century, in the contest of the Church with the Arians, no less than it has been in the Second century, in the struggle against Gnostics, Sabellians, and Montanists. All parties in the dispute used to appeal to Scripture. Heretics, even Gnostics and Manichees, used to quote Scriptural texts and passages and to invoke the authority of the Holy Writ. Moreover, exegesis was at that time the main, and probably the only, theological method, and the authority of the Scripture was sovereign and supreme. The Orthodox were bound to raise the crucial hermeneutical question: What was the principle of interpretation? Now, in the Second century the term "Scriptures" denoted primarily the Old Testament and, on the other hand, the authority of these "Scriptures" was sharply challenged, and actually repudiated, by the teaching of Marcion. The Unity of the Bible had to be proved and vindicated. What was the basis, and the warrant, of Christian, and Christological, understanding of "Prophecy," that is — of the Old Testament? It was in this historical situation that the authority of Tradition was first invoked. Scripture belonged to the Church, and it was only in the Church, within the community of right faith, that Scripture could be adequately understood and correctly interpreted. Heretics, that is — those outside of the Church, had no key to the mind of the Scripture. It was not enough just to read and to quote Scriptural words — the true meaning, or intent, of Scripture, taken as an integrated whole, had to be elicited. One had to grasp, as it were in advance, the true pattern of Biblical revelation, the great design of God’s redemptive Providence, and this could be done only by an insight of faith. It was by faith that Christuszeugniss could be discerned in the Old Testament. It was by faith that the unity of the tetramorph Gospel could be properly ascertained. But this faith was not an arbitrary and subjective insight of individuals — it was the faith of the Church, rooted in the Apostolic message, or kerygma, and authenticated by it. Those outside of the Church were missing precisely this basic and overarching message, the very heart of the Gospel. With them Scripture was just a dead letter, or an array of disconnected passages and stories, which they endeavored to arrange or re-arrange on their own pattern, derived from alien sources. They had another faith. This was the main argument of Tertullian in his passionate treatise De praescriptione. He would not discuss Scriptures with heretics — they had no right to use Scriptures, as they did not belong to them. Scriptures were the Church’s possession. Emphatically did Tertullian insist on the priority of the "rule of faith," regula fidei. It was the only key to the meaning of the Scripture. And this "rule" was Apostolic, was rooted in, and derived from, the Apostolic preaching. C. H. Turner has rightly described the meaning and the intention of this appeal or reference to the "rule of faith" in the Early Church. "When Christians spoke of the ‘Rule of Faith’ as ‘Apostolic,’ they did not mean that the Apostles had met and formulated it … What they meant was that the profession of belief which every catechumen recited before his baptism did embody in summary form the faith which the Apostles had taught and had committed to their disciples to teach after them." This profession was the same everywhere, although the actual phrasing could vary from place to place. It was always intimately related to the baptismal formula [C. H. Turner, Apostolic Succession, in "Essays on the Early History of the Church and the Ministry," edited by H. B. Swete (London, 1918), pp. 101-102. See also Yves M. J. Cougar, O.P., La Tradition et les traditions, 11. Essai Théologique (Paris, 1963), pp. 21 ss]. Apart from this "rule" Scripture could be but misinterpreted. Scripture and Tradition were indivisibly interwined for Tertullian. Ubi enim apparuerit esse veritatem disciplinae et fidei christianae, illic erit veritas scripturarum et expositionum et omnium traditionum christianarum. ["For only where the true Christian teaching and faith are evident will the true Scriptures, the true interpretations, and all the true Christian traditions be found;" XIX. 3]. The Apostolic Tradition of faith was the indispensable guide in the understanding of Scripture and the ultimate warrant of right interpretation. The Church was not an external authority, which had to judge over the Scripture, but rather the keeper and guardian of that Divine truth which was stored and deposited in the Holy Writ [Cf. E. Flesseman-van-Leer, Tradition and Scripture in the Early Church (Assen, 1954), pp. 145-185; Damien van den Eynde, Les Normes de l’Enseignment Chrétien dans la litterature patristique des trois premiers siècles (Gembloux-Paris, 1933), pp. 197-212; J. K. Stirniman, Die Praescriptio Tertullians im Lichte des römischen Rechts und der Théologie (Freiburg, 1949); and also the introduction and notes of R. F. Refoulé, O.P., in the edition of De praescriptione, in the "Sources Chrétiennes," 46 (Paris, 1957)].