For the past several months I have been attempting to articulate a point to my Orthodox and Catholic interlocutors, but with little success. Thanks to James White, I think I finally know what I've been trying to say.
One argument against Protestants I've heard used a lot recently is that without an infallible list of books that belong in the canon (an infallible table of contents, if you will), we are left without absolute certainty that we actually have the right books. This lack of certainty seems to jeopardize any attempt at turning around and claiming this fallibly collected list of books to be an infallible and binding authority. But does the Orthodox or Catholic have it any better?
As White points out, each individual Orthodox or Catholic must choose, by his own fallible reasoning faculties, to accept that the church is infallible. But this decision itself is necessarily fallible. And a fallible decision cannot then produce infallible certainty.
This applies not only to the church's proclamation of the canon, but to the very claim of church infallibility itself. Can the Orthodox or Catholic be absolutely certain that the church is infallible? Not at all, for once again their belief in church infallibility is itself a fallible belief.
If the Protestant lacks assurance in his Bible, the Orthodox and Catholic must likewise lack assurance not only in the Bible, but also in the church that produced it. Unless, of course, we accept that our own fallible understanding of God's infallible Word is the best we can hope for in this life, as we look forward to that day when we shall at last know fully.