Self-Authenticating
We are applying Scripture to the question of which books belong in the New Testament. Perhaps this is a more tangible way to think of a self-authenticating canon because it is not all that different (in principle) from the way we apply the teaching of Scripture to any other question before us, whether politics, science, the arts, or anything else.
Michael Kruger, Canon Revisited: Establishing the Origins and Authority of the New Testament Books (Wheaton, IL: Crossway, 2012), 134