Tertullian and Iranaeus on Sola Scriptura

Tertullian (c. 155-220): Arguing with Hermogenes' teaching that matter is eternal, "But whether all things were made out of any underlying matter, I have yet failed anywhere to find. Where such a statement is written, Hermogenes' shop must tell us. If it is nowhere written, then let it fear the woe which impends on all who add or take away from the written word." Tertullian "condemns as madness" the notion that there was some kind of secret unwritten tradition of the Apostles. This was the doctrine of the Gnostics who believed that there was "secret knowledge" known and revealed only to a select few.

Iranaeus (c. 130-200) in his Against Heresies argues that the Scriptures where the safeguarding of the traditions of the apostles. According to Iranaeus, there are no unwritten traditions of the Apostles. Scripture is the authoritative record of the doctrines, teachings, and practices of the Apostles (cf. Against Heresies, III.1,1.)

These fathers did indeed teach that the Scriptures were to be understood and read in accordance with the regula fidei (the rule of faith) which was itself the received summary of what the Scriptures teach. But the apostolic tradition and the regula fidei both had their source in the Scriptures themselves.

The Shape of Sola Scriptura, 22-26)