1. When, however, they are confuted from the Scriptures, they turn round and accuse these same Scriptures, as if they were not correct, nor of authority, and [assert] that they are ambiguous, and that the truth cannot be extracted from them by those who are ignorant of tradition. For [they allege] that the truth was not delivered by means of written documents, but viva voce: wherefore also Paul declared, “But we speak wisdom among those that are perfect, but not the wisdom of this world.” And this wisdom each one of them alleges to be the fiction of his own inventing, forsooth; so that, according to their idea, the truth properly resides at one time in Valentinus, at another in Marcion, at another in Cerinthus, then afterwards in Basilides, or has even been indifferently in any other opponent, who could speak nothing pertaining to salvation. For every one of these men, being altogether of a perverse disposition, depraving the system of truth, is not ashamed to preach himself.
Irenaeus, Against Heresies, 3.2.1