All needful dogmas are perfectly contained in Old and New Testament Scripture; reasons from canon, testament, praises, and Isaiah
VIII. We therefore assert that all dogmas whose knowledge is necessary for salvation, for catechetical institution, and finally for certainty are perfectly contained in the books of the Old and New Testament, and sufficiently handed down — either expressly, as to the wording itself, or equivalently, as to likeness, by evident equipollence or by a legitimate and catholic consequence.
The reason for the perfection of sacred Scripture that we assert is, first, from the notion of a canon, because it sets forth a rule of the things that are for us to be believed and done (Galatians 6:16; Philippians 3:16). But a rule is a certain measure to which nothing can be taken away, nothing added, by private authority — which Gerson (tome 1, part 2, in the treatise On the examination of doctrine) wisely applied to the canon of sacred Scripture. And of this rule some parts are essential, some integral, and must be prudently distinguished. In the former the substance of things to be believed and done is looked to; in the latter the mode and manner of application. In the former rather than in the latter the force and nature of a rule is placed. And so the whole of Scripture indeed, yet not the whole of what is in Scripture, is established by us as a rule — just as in a material rule not everything that belongs to the rule is itself the rule.
Second, the same is proved by the notion of a testament, by which appellation those sacred books are designated (2 Corinthians 3:6, 14; Galatians 3:17; 4:24; Ephesians 2:12; Hebrews 9:15–17).
Third, from those praises which it has from its Author and from its efficacy (2 Peter 1:21; Psalm 19:7–8; 2 Timothy 3:15–16).
Fourth, from Isaiah's most weighty warning, calling everyone from human and diabolical inventions back to Mosaic and prophetic Scripture alone (Isaiah 8:20): To the law and to the testimony: if they do not speak according to this word, they have no dawn of light.
Latin
VIII. Assertimus igitur dogmata omnia, quorum tum ad salutem, tum ad catecheticam institutionem, tum denique ad certitudinem necessaria est cognitio, libris veteris ac novi Testamenti perfecte contineri, sufficienter tradi, vel αὐτολεξεί expresse, quantum ad ipsam dictionem: vel ἰσοδυνάμως, quantum ad similitudinem, per aequipollentiam evidentem aut consequentiam legitimam & catholicam. RATIO perfectionis sacrae Scripturae a nobis asserta, 1. Est a notione canonis, quia canonem sive regulam proponit eorum, quae nobis sunt credenda & facienda, Gal. 6.16. Phil. 3.16. Est autem regula mensura quaedam, cui nihil adimi, nihil adjici potest privata authoritate. Quod & Gerson tom. 1. parte 2. in tractatu de examin. doctrin. ad sacrae Scripturae canonem sapienter accommodavit. Sunt autem regulae hujus partes aliae essentiales, aliae integrales, ex quo prudenter distinguendae. In illis rerum credendarum & faciendarum substantia: in his vero modus & ratio applicationis spectatur. In illis potius, quam in his regulae vis & natura posita est. Et sic tota quidem Scriptura, at non totum Scripturae, regula a nobis statuitur: sicuti nec in regula materiali, quicquid est regulae, idem est regula. 2. Idem evincit ratio testamenti, cujus appellatione sacri illi libri indigitantur, 2. Cor. 3.6.14. Gal. 3.17.4.24. Eph. 2.12. Heb. 9.15.16.17. 3. Ab illius elogiis, quae habet ab autore & efficacia, 2. Pet. 1.21. Psal. 19.8. 2. Tim. 3.15.16. 4. A gravissima Esaiae commonestatione, quoslibet ab humanis & diabolicis commentis ad solam Mosaicam & propheticam Scripturam revocantis, cap. 8.20. Ad legem & ad testimonium: si non dixerint juxta hoc verbum, nulla ipsis est lucis scintilla.