The fundamental claim of the Roman Catholic model is that sola scriptura is untenable because, without some external infallible authority, there is no way to know which books are to be included in the canon. This epistemological challenge in the words of Catholic author Patrick Madrid, is that Christians do not have an "inspired table of contents" that reveals "which books belong and which books do not." If only Christians had this inspired table of contents, then we would not need the authoritative rulings of the Roman Catholic Church to authenticate the Canon. Although such an argument is made repeatedly within Catholic writings, it proves to be problematic upon closer examination.
Imagine for a moment that God has inspired another document in the first century that contained this "table of contents" and had given it to the church. We will call this the twenty-eighth book of the New Testament canon. Would the existence of such a book have satisfied the Catholic concerns? Would this allow Catholics to affirm sola scriptura and deny the need for an infallible church? Not at all. Instead, they would simply ask the next logical question: "On what basis do you know that this twenty-eighth book comes from God?" And even if it were argued that God has given a twenty-ninth book saying the twenty-eighth book came from God, and the same objection would still apply: "Yes, but how do you know the twenty-ninth book came from God?" And on it would go. The Catholic objection about the need for a "table of contents," therefore, misses the point entirely. Even if there were another document with such a table, this document would still need to be authenticated as part of the Canon. After all, what if there were multiple table-of-contents-type books floating around in the early church? How would we know which one was from God? In the end, therefore, the Roman Catholic objection is to some extent artificial. Such a "table of contents" would never satisfy their concerns, even if it were to exist, because they have already determined, a priori, that no document could ever be self-attesting. In other words, built into the Roman Catholic model is that any written revelation (whether it contains a "table of contents" or not) will require external approval and authentication from an infallible church (Pg. 42-43).I recall some time back, someone on Jason Stellman's Facebook page asked him if he had read Kruger's book, (someone, perhaps Jason, had mentioned the supposed Protestant lack of an inspired canon) and he responded something to the effect that any Protestant answer to the question of canon was irrelevant since it begins by begging the question. Chew on that one for a bit, and if you're a thinking person it should trouble you endlessly. There is no answering someone who has truly decided the magisterium holds all answers, truth, and authority. But if it were possible, Canon Revisited would be a great place to start.
By the way, Westminster Books is currently selling Canon Revisited for 40% off the regular price.