The canon of Scripture is an artifact of revelation rather than an object of revelation. By "artifact" I mean something that is a feature not normally present but visible as a result of an external agent or action.
While the Romanist treats the canon as an object of revelation, it is the result (hence an "artifact") of revelation. In other words, the canonical list of the books of Holy Scripture are the result of God's revelatory work, and not the object of what God has revealed.
A Christian's recognition of these books is result of God's working in him to will and to believe.
I believe 1) Scripture's own witness of its inspiration, and 2) that God confirms that by the illuminating power of the Holy Spirit. I drawn a distinction (as the Reformers did before me) between the Spirit's revelatory work and his illuminating work.
In his work, Against the Epistle of Manichaeus Called Fundamental, Chapter 14, Augustine made this point.
Augustine (354-430) in response to Manichaeus:
You can find nothing better than to praise your own faith and ridicule mine. So, after having in my turn praised my belief and ridiculed yours, what result do you think we shall arrive at as regards our judgment and our conduct, but to part company with those who promise the knowledge of indubitable things, and then demand from us faith in doubtful things? while we shall follow those who invite us to begin with believing what we cannot yet fully perceive, that, strengthened by this very faith, we may come into a position to know what we believe by the inward illumination and confirmation of our minds, due no longer to men, but to God Himself.Latin text:Nihil aliud elegisti, nisi laudare quod credis, et irridere quod credo. Cum igitur etiam ego vicissim laudavero quod credo, et quod credis irrisero; quid putas nobis esse judicandum, quidve faciendum, nisi ut eos relinquamus, qui nos invitant certa cognoscere, et postea imperant ut incerta credamus; et eos sequamur, qui nos invitant prius credere, quod nondum valemus intueri, ut ipsa fide valentiores facti, quod credimus intelligere mereamur, non jam hominibus, sed ipso Deo intrinsecus mentem nostram illuminante atque firmante?
Citation: Augustine, Contra Epistolam Manichaei Quam vocant Fundamenti, Liber Unus, Caput XIV, PL 42:183; translation in NPNF1: Vol. IV, Against the Epistle of Manichaeus Called Fundamental, Chapter 14.
We acknowledge with Augustine that the Church is most often the initial and outward means by which men are called to faith in Christ, but God brings us to the place (as Augustine put it) "to know what we believe by the inward illumination and confirmation of our minds, due no longer to men, but to God Himself."
Scripture itself furnishes us with clear illustration of this in the fourth chapter of John’s gospel. After having dealings with Christ, the woman of Samaria returns to her city, and there bears witness to Christ.
And many of the Samaritans of that city believed in Him because of the word of the woman who testified, “He told me all that I ever did.”
So when the Samaritans had come to Him, they urged Him to stay with them; and He stayed there two days. And many more believed because of His own word.
Then they said to the woman, “Now we believe, not because of what you said, for we ourselves have heard Him and we know that this is indeed the Christ, the Savior of the world.”
The point this passage illustrates is this - that though it was the woman’s witness which initially induced belief in Christ, nonetheless, the confirmation of their faith came to rest in the testimony of Christ’s own word. While the woman’s witness was true and sufficiently credible to move the inhabitants of the city, it does not follow that she became the infallible bulwark of their subsequent faith. The inhabitants of the city came to rest not in her word, but Christ’s own word.
Likewise, though the Church (or the witness of an individual Christian) is often the initial and outward means by which men are called to faith in Christ, it does not follow that this renders the church or the individual Christian with the attribute of infallibility.
God's own word is a spiritual reality which is sufficient to create faith in itself. No church or human being is able to accomplish that supernatural work.
The Apostle John wrote, “If we receive the witness of men, the witness of God is greater; for this is the witness of God which He has testified of His Son” (1 Jn. 5:9).
Needing no support, the witness of God stands by itself. God’s own testimony is decisive and inexpugnable. If Holy Scripture is in reality the God-breathed word, then it must be self-authenticating, and in need of no human sanction. It is nothing less than a compromise of the integrity of God’s own witness to presuppose Scripture to be anything other than the living oracles of the Creator and Redeemer of mankind. To hold in suspension, as it were, the question of God’s speaking in Scripture until some external, authoritative criterion outside of God himself is applied as the deliberative, decisive court of appeal is a de facto assault on the truth that “the witness of God is greater.”
Chrysostom (349-407): Besides, what benefit would there be in a homily when prayer has not been joined to it? Prayer stands in the first place; then comes the word of instruction. And that is what the apostles said: "Let us devote ourselves to prayer and the ministry of the word." Paul does this when he prays at the beginning of his epistles so that, like the light of a lamp, the light of prayer may prepare the way for the word. If you accustom yourselves to pray fervently, you will not need instruction from your fellow servants because God himself, with no intermediary, enlightens you mind.
Citation: John Chrysostom, FC, Vol. 72, On the Incomprehensible Nature of God, Homily 3.35, (Washington, D.C.: The Catholic University of America Press, 1984), pp. 111.
We have strong precedent in the some works of the Early Church Fathers (ECFs) that indicate there was also in their time a recognition of the fact that God's word is self-authenticating. Some examples of this precedent are shown below.
Nemesius of Emesa (around the end of the 4th century):
But for us the sufficient demonstration of the soul’s immortality is the teaching of Holy Scripture, which is self-authenticating because inspired of God.Greek text:
ἡμῖν δὲ ἀρκεῖ, πρὸς ἀπόδειξιν τῆς ἀθανασίας αὐτῆς, ἡ τῶν θεῖων λογῖων διδασκαλία, τὸ πιστὸν ἀθ’ ἐαυτῆς ἔχουσα, διὰ τὸ θεόπνευστος εἶναι•Citation: Nemesius of Emesa, De Natura Hominis, Caput II.18, Migne PG 40:589; translation in William Telfer, ed., The Library of Christian Classics, Vol. IV, Cyril of Jerusalem and Nemesius of Emesa: On the Nature of Man, Chapter 2 Of the Soul (Philadelphia: The Westminster Press, 1955), p. 292. (It is believed that Nemesius of Emesa wrote this work sometime between A.D. 392-400.)
Salvian the Presbyter (5th century):
I need not prove by arguments what God Himself proves by His own words. When we read that God says He perpetually sees the entire earth, we prove thereby that He does see it because He Himself says He sees it. When we read that He rules all things He has created, we prove thereby that He rules, since He testifies that He rules. When we read that He ordains all things by His immediate judgment, it becomes evident by this very fact, since He confirms that He passes judgment. All other statements, said by men, require proofs and witnesses. God’s word is His own witness, because whatever uncorrupted Truth says must be the undefiled testimony to truth.Latin text:
Neque enim necesse est ut argumentis a me probetur quod hoc ipso quia a Deo dicitur comprobatur. Itaque cum legimus dictum a Deo quia aspiciat jugiter omnem terram, hoc ipso probamus quod aspicit quia aspicere se dicit; cum legimus quod regat cuncta quae fecit, hoc ipso approbamus quod regit, quia se regere testatur; cum legimus quod praesenti judicio universa dispenset, hoc ipso est evidens quod judicat quia se judicare confirmat. Alia enim omnia, id est, humana dicta, argumentis ac testibus egent. Dei autem sermo ipse sibi testis est, quia necesse est quidquid incorrupta veritas loquitur, incorruptum sit testimonium veritatis.Citation: Salvian the Presbyter, Sancti Salviani Massiliensis Presbyteri De Gubernatione Dei, Liber Tertius, I, PL 53:1567; translation in FC, Vol. 3, The Writings of Salvian, The Presbyter, The Governance of God, Book 3.1 (New York: CIMA Publishing Co., Inc., 1947), pp. 68-69.
Epiphanius of Salamis (310/320-403):
But the truth is always steadfast and needs no assistance. It is self-authenticating, and always established in the sight of the true God.Greek text:
τῆς ἀληθείας ἀεὶ ἑδραίας οὔσης καὶ μὴ χρείαν ἐχούσης βοηθείας, ἀλλὰ αὐτοσυστάτου οὔσης καὶ παρὰ θεῷ τῷ ὄντως ὄντι ἀεὶ συνιστωμένης.Citation: Epiphanius of Salamis, Adversus Haereses, Liber I, Tom. III, XLIV, §1, PG 41:821; translation by Frank Williams, trans., The Panarion of Epiphanius of Salamis: Book I (Sects 1-46) 44. Against Apelleans, 1,3 (Leiden: E.J. Brill, 1994), p. 340.
The truth is self-authenticating and cannot be overthrown even if wickedness shamelessly opposes the precept of truth.Greek text:
αὐτοσυστάτης οὔσης τῆς ἀληθείας, καὶ μὴ δυναμένης καθαιρεῖσθαι, κἄν τε ἀντιπράττοι ἡ ἀνομία ἀναισχυντίᾳ φερομένη τῷ τῆς ἀληθείας θεσμῷ,Citation: Epiphanius of Salamis, Adversus Haereses, Liber II, Tom. II, LXVI, §10, PG 42:44; translated by Frank Williams, trans., The Panarion of Epiphanius of Salamis, Books II and III (Sects 47-80, De Fide), 66. Against Manichaeans, 10,4 (Leiden: E.J. Brill, 1994), p. 230.
Clement of Alexandria (150 - c. 215):
It will naturally fall after these, after a cursory view of theology, to discuss the opinions handed down respecting prophecy; so that, having demonstrated that the Scriptures which we believe are valid from their omnipotent authority, we shall be able to go over them consecutively, and to show thence to all the heresies one God and Omnipotent Lord to be truly preached by the law and the prophets, and besides by the blessed Gospel.Greek text:
Οἷς ἑπόμενον ἂν εἴη μετὰ τὴν ἐπιδρομὴν τῆς θεολογίας τὰ περὶ προφητείας παραδεδομένα διαλαβεῖν, ὡς καὶ τὰς γραφὰς αἷς πεπιστεύκαμεν κυρίας οὔσας ἐξ αὐθεντείας παντοκρατορικῆς ἐπιδείξαντας προϊέναι διʼ αὐτῶν εἱρμῷ δύνασθαι, καὶ ἁπάσαις ἐντεῦθεν ταῖς αἱρέσεσιν ἕνα δεικνύναι Θεὸν, καὶ Κύριον παντοκράτορα τὸν διὰ νόμου καὶ προφητῶν, πρὸς δὲ καὶ τοῦ μακαρίου εὐαγγελίου γνησίως κεκηρυγμένον.Citation: Clement of Alexandria, Stromata, Liber IV, Caput 1, PG 8:1216; translation in ANF: Vol. II, The Stromata, Book IV, Chapter 1.
For it was not befitting that, when God was speaking to man, He should confirm His words by arguments, as though He would not otherwise be regarded with confidence: but, as it was right, He spoke as the mighty Judge of all things, to whom it belongs not to argue, but to pronounce sentence.Latin text:
Nес enim decebat ut cum deus ad hominem loqueretur, argumentis adsereret suas voces, tamquam aliter fides ei non haberetur, sed ut oportuit locutus est tamquam rerum omnium maximus iudex, cuius est non argumentari, sed pronuntiare.Citation: Lactantius, L. Caeli Firmiani Lactanti Opera omnia, Volume 19 (in Corpus Scriptorum Ecclesiasticorum Latinorum, Samuel Brandt Editor)(F. Tempsky, 1890), p. 197, lines 4-8; translation in ANF: Vol. VII, The Divine Institutes, Book III, Chapter I. See also FC, Vol. 49, The Divine Institutes, Book III, Chapter 1 (Washington D.C.: The Catholic University Press, 1963), pp. 165-166. Alternative translation:
... when God was addressing man, addition of arguments to his words, as if he would not otherwise be believed, was not appropriate; he spoke as the supreme judge of all creation ought to speak, his business being not discussion but declaration.Citation: Lactantius: Divine institutes, Volume 40 of Translated Texts for Historians, Bowen et al. ed. (Liverpool University Press, 2003), p. 169 at 11
These ECFs, to name a few, are examples in the ancient church who (like us) believed Scripture to be self-authenticating.