Ok where do we start?
Let’s start from the beginning. And yes, those quotations are genuine, but they don’t prove Sola Scriptura, they prove something narrower: Augustine believed that canonical Scripture has a unique, divinely guaranteed authority and inerrancy that the writings of individual bishops do not possess, and a Catholic has no reason to deny that. Augustine says exactly this in Letter 82.3 when he reserves complete freedom from error to the canonical books. (Augustine, Letter 82.3.)
But Sola Scriptura means more than “Scripture is uniquely inspired and inerrant.” In its classical Reformed formulation, Scripture is the sole infallible rule for the Church: the whole counsel of God necessary for faith and life is contained in or deducible from Scripture, nothing is to be added as a binding tradition, and the final judge of religious controversies is the Holy Spirit speaking in Scripture. See Westminster Confession of Faith 1.6 and 1.10.
The problem is that Augustine explicitly accepts apostolic traditions not contained in Scripture.
In the very same work from which the quotation about Scripture being superior to bishops and councils is taken, On Baptism Against the Donatists, Augustine defends the Church’s practice of not rebaptizing heretics: he says that this practice comes, in his judgment, from apostolic tradition, and he places it among things preserved universally by the Church even though they are not found in the apostles’ writings or in later councils. This is On Baptism II.7.12.
That is extremely important, as Augustine simultaneously believes:
- Canonical Scripture possesses an authority and inerrancy unique to itself.
- Authentic apostolic traditions can exist outside the written apostolic texts and can be preserved authoritatively by the universal Church.
Those two propositions are perfectly compatible with a Catholic doctrine of Scripture and Tradition. They are not equivalent, nor are they compatible, with the Reformation principle of Sola Scriptura.
Augustine makes the point even more explicitly in Letter 54 to Januarius: he distinguishes practices prescribed in canonical Scripture from other things Christians hold on the authority “not of Scripture, but of tradition,” and says that universal traditions may reasonably be regarded as instituted by the Apostles themselves or by plenary councils. (Letter 54.1.)
The quotation from On Christian Doctrine II.9 doesn’t change this.
Augustine certainly says that all matters concerning faith and Christian life can be found among the things plainly taught in Scripture, and thht is strong evidence for what theologians often call the material sufficiency of Scripture.
But it It does not establish Sola Scriptura as the exclusive rule of faith. In fact, immediately before that passage, Augustine says that in determining which books belong to the canon, the Christian should follow the judgment of the Catholic Churches, giving particular weight to Churches associated with the Apostles. (On Christian Doctrine II.8–9.)
Augustine clearly teaches the unique inspiration, inerrancy and superior authority of canonical Scripture, but he doesn’t teach that no authoritative apostolic Tradition exists outside Scripture. And Irenaeus explicitly appeals to Scripture, apostolic Tradition and episcopal succession as means by which the apostolic faith is preserved.
Therefore saying that “Irenaeus and Augustine made Sola Scriptura crystal clear” is simply too strong. It works only if Sola Scriptura is redefined to mean merely “Scripture is uniquely inspired and superior to later human writings.” But that proposition is not distinctively Protestant at all.
Indeed, Catholic doctrine itself teaches that Scripture is divinely inspired and that the Magisterium is not above the Word of God but serves it, while Scripture and Apostolic Tradition belong to the one apostolic deposit transmitted to the Church. See Vatican II, Dei Verbum 9–10.
So Augustine can legitimately be cited in support of the supreme and unique status of inspired Scripture. He cannot legitimately be cited as “crystal-clear” evidence that the early Church rejected authoritative unwritten Apostolic Tradition. His own writings explicitly say otherwise. Augustine regards Scripture as the supreme inspired norm, while regarding the Church’s rule of faith and the authoritative judgment of the universal Church as normative for resolving doctrinal disputes over its interpretation.
Irenaeus is even clearer on this point. So clear that I find it baffling that you cite him in order to prove Sola Scriptura.
In fact, in Against Heresies 3.2 CHURCH FATHERS: Against Heresies, III.3 (St. Irenaeus) he said: “Since, however, it would be very tedious, in such a volume as this, to reckon up the successions of all the Churches, we do put to confusion all those who, in whatever manner, whether by an evil self-pleasing, by vainglory, or by blindness and perverse opinion, assemble in unauthorized meetings; [we do this, I say,] by indicating that tradition derived from the apostles, 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; as also [by pointing out] the **faith**preached to men, which comes down to our time by means of the successions of the bishops. For it is a matter of necessity that every Church should agree with this Church, on account of its preeminent authority [potiorem principalitatem].”
Irenaeus explicitly recognized the doctrinal authority of the Roman Church with a force that no modern Catholic Bishop would ever use.
