No, St.Roymond, that isn’t how the Fathers describe doctrinal authority, and it isn’t how Nicaea operated. The Fathers certainly treat Scripture as inspired, normative, and decisive, but not as a free-standing umpire detached from apostolic tradition ( the rule of faith), baptismal confession, and the public teaching of the Church.
Once rival parties appeal to Scripture, the Fathers don’t say that private exegesis is enough; they appeal to the Church’s received faith as the context in which Scripture is rightly read.
But since you made such an unequivocal statement, namely “ the Fathers had one, called scripture; they referred to it as the canon, the guide, the umpire”, let us see whether it stands up in light of what the Church Fathers actually said.
Let us set opinions aside and examine the facts.
Iraeneus is one of the clearest witnesses. In Against Heresies (Book IV, Chapter 26.5) CHURCH FATHERS: Against Heresies, IV.26 (St. Irenaeus) he says: “Where, therefore, the gifts of the Lord have been placed, there it behooves us to learn the truth, [namely,] from those who possess that succession of the Church which is from the apostles, and among whom exists that which is sound and blameless in conduct, as well as that which is unadulterated and incorrupt in speech. For these also preserve this faith of ours in one God who created all things; and they increase that love [which we have] for the Son of God, who accomplished such marvellous dispensations for our sake: and they expound the Scriptures to us without danger, neither blaspheming God, nor dishonouring the patriarchs, nor despising the prophets. “
Then in Against Heresies Book III chapter 4 CHURCH FATHERS: Against Heresies, III.4 (St. Irenaeus) Irenaeus says: “Suppose there arise a dispute relative to some important question among us, should we not have recourse to the most ancient Churches with which the apostles held constant intercourse, and learn from them what is certain and clear in regard to the present question? For how should it be if the apostles themselves had not left us writings? Would it not be necessary, [in that case,] to follow the course of the tradition which they handed down to those to whom they did commit the Churches?”
That’s as far from Sola Scriptura as it gets: it’s Scripture read within apostolic tradition preserved in the churches.
Tertullian says the same thing in a different key. In Prescription against Heretics 19 CHURCH FATHERS: The Prescription Against Heretics (Tertullian) he explicitly says “Our appeal, therefore, must not be made to the Scriptures; nor must controversy be admitted on points in which victory will either be impossible, or uncertain, or not certain enough. But even if a discussion from the Scriptures should not turn out in such a way as to place both sides on a par, (yet) the natural order of things would require that this point should be first proposed, which is now the only one which we must discuss: With whom lies that very faith to which the Scriptures belong. From what and through whom, and when, and to whom, has been handed down that rule, by which men become Christians? For wherever it shall be manifest that the true Christian rule and faith shall be, there will likewise be the true Scripture and expositions thereof, and all the Christian traditions”. His point is not that Scripture is false or secondary, but that Scripture doesn’t function as a self-interpreting court above the Church. The Church’s regula fidei is the public key to Scripture against heretical misuse.
Basil is even more explicit against the idea that apostolic tradition simply equals the New Testament text. In De Spiritu Sancto 9.22 CHURCH FATHERS: De Spiritu Sancto (Basil) he distinguishes what is drawn “from Holy Scripture” from what is received from the “unwritten tradition of the Fathers.” He says: “Let us now investigate what are our common conceptions concerning the Spirit, as well those which have been gathered by us from Holy Scripture concerning It as those which we have received from the unwritten tradition of the Fathers.” That distinction alone is enough to refute the claim that the Fathers identified all binding apostolic tradition with the written New Testament and nothing more.
The Nicene evidence makes the same point in the anti-Arian controversy. Eusebius of Caesarea, explaining Nicaea afterward, says https://www.fourthcentury.com/wp-content/uploads/2023/11/Eusebius-Letter-about-Nicaea-3.pdf that the creed he presented was what he had received “from the bishops who preceded us,” in his first catechesis, at baptism, and from the divine Scriptures. He also says the meaning of homoousios was examined by “intense questioning and explaining.” So the council didn’t proceed by bare proof-texting. It judged the Arian reading of Scripture against the Church’s inherited baptismal and doctrinal faith, and then used a non-biblical term to secure the right sense.
J. N. D. Kelly’s classic synthesis says much the same. In his discussion of Irenaeus and Tertullian, he explains that Tertullian didn’t confine apostolic tradition to the New Testament, that the regula fidei functioned as the guide to correct exegesis in the Church, and that Scripture and tradition were not treated as rival sources but as coincident in content and publicly preserved in the Church’s witness. That isn’t “Scripture alone” by any stretch ot the imagination.
I’m going to quote some of his verbatim words in some paragraphs (not everything otherwise it would be too long, they are selected paragraphs ) from here Full text of "103911481-J-N-D-Kelly-Early-Christian-Doctrines.pdf (PDFy mirror)"
CHAPTER II
TRADITION AND SCRIPTURE
- “Broadly speaking, the problem we have raised is the problem of Tradition (as we now call it) and Scripture, i.e. of the relation between the two. Other questions are closely linked with it, such as the place accorded to reason in the formulation of Christian truth; but it will be well to confine ourselves to the central issue. God Himself, all the early theologians acknowledged, was the ultimate author of the revelation; but He had committed it to prophets and inspired lawgivers, above all to the apostles who were eye-witnesses of the incarnate Word, and they had passed it on to the Church. Hence, when asked where the authentic faith was to be found, their answer was clear and unequivocal: in a general way it was contained in the Church’s continuous tradition of teaching, and more concretely in the Holy Scriptures. These were in fact the twin — as we shall see, overlapping — authorities to which Christians looked for the confirmation of their beliefs.
- “Hence by tradition the fathers usually mean doctrine which the Lord or His apostles committed to the Church, irrespective of whether it was handed down orally or in documents, and in the earlier centuries at any rate they prefer to employ other words or phrases to designate the Church’s unwritten traditional teaching. The ancient meaning of the term is well illustrated by Athanasius’s reference 1 to ‘the actual original tradition, teaching and faith of the Catholic Church, which the Lord bestowed, the apostles proclaimed and the fathers safeguarded’.”
- “On the other hand, the ancient idea that the Church alone,
in virtue of being the home of the Spirit and having preserved
the authentic apostolic testimony in her rule of faith, liturgical
action and general witness, possesses the indispensable key to
Scripture, continued to operate as powerfully as in the days of
Irenaeus and Tertullian. Clement, for example, blamed 2 the
mistakes of heretics on their habit of ‘resisting the divine tradi-
tion’, by which he meant their incorrect interpretation of
Scripture; the true interpretation, he believed, was an apostolic
and ecclesiastical inheritance. “ - It should be unnecessary to accumulate further evidence. Throughout the whole period Scripture and tradition ranked
as complementary authorities, media different in form but coincident in content. To inquire which counted as superior or more ultimate is to pose the question in misleading and
anachronistic terms. If Scripture was abundantly sufficient in
principle, tradition was recognized as the surest clue to its inter-
pretation, for in tradition the Church retained, as a legacy from
the apostles which was embedded in all the organs of her in-
stitutional life, an unerring grasp of the real purport and mean-
ing of the revelation to which Scripture and tradition alike bore
witness. “
So the patristical and historical answer is straightforward: the early Church didn’t function by sola scriptura, and Nicaea didn’t defeat Arius by naked proof-texting: the Fathers appealed constantly to Scripture, but they did so within apostolic tradition, the rule of faith, baptismal confession, succession, and conciliar judgment. Tradition was not a second revelation above Scripture; it was the Church’s public, inherited norm for identifying the right reading of Scripture.
P.s: in Kelly’s work at a certain point we can read the words “okottos iKKXijataaTtKos”. That’s almost certainly a corrupt OCR from the greek σκοπός ἐκκλησιαστικός (skopos ekklēsiastikos), namely the ecclesiastical scope. I’m referring to the part where Kelly writes the following: “Athanasius himself, after dwelling on the entire adequacy of Scripture, went on to emphasize 3 the desirability of having sound teachers to expound it. Against the Arians he
flung the charge* that they would never have made shipwreck of the faith had they held fast as a sheet-anchor to the okottos
iKKXijataaTtKos, meaning by that the Church’s peculiar and traditionally handed down grasp of the purport of revelation. “
In that context, as I said, it’s almost certainly a corrupt OCR from σκοπός ἐκκλησιαστικός.