Because the list of canonical books is itself not found in Scripture—as one can find the Ten Commandments or the names of Christ’s Apostles—any such list, whether Protestant or Catholic, would be an item of extra-Biblical theological knowledge.There is a rather obvious problem with this claim. Given Scripture (as Beckwith does for the Ten Commandments or the names of Christ's apostles) a list of canonical books is readily derivable from the Scriptures. As a thought experiment, one could imagine receiving a Bible with the table of contents accidentally smudged beyond recognition. That table of contents could be easily restored from the text in a matter of moments. Given Scripture the list of canonical books, while not found as such, is easily derived.
Of course, if one doesn't grant that we already have the Scriptures, as such, the matter of creating a list becomes more difficult. But that's not a challenge facing sola Scriptura. Sola Scriptura begins with the reader possessing the Scriptures. It is a given of the system.
After his initial reflection, Beckwith provides an historical anecdote:
Take for example a portion of the revised and expanded Evangelical Theological Society statement of faith suggested by the two ETS members following my return to the Catholic Church. (The proposed change failed to garner enough votes for passage, losing by a 2-1 margin). It states that “this written word of God consists of the 66 books of the Old and New Testaments and is the supreme authority in all matters of belief and behavior.”I think we all understand the intent behind this sort of amendment, whether or not it was needed for the ETS statement of faith. But let's see what Beckwith's reflection on this anecdote is:
But the belief that the Bible consists only of 66 books is not a claim of Scripture—since one cannot find the list in it—but a claim about Scripture as a whole.One cannot find the list in it, only in the sense that one cannot find the list of Psalms in the book of Psalms. In other words, the list is not given as such. However, a list may readily be generated from the Bible or from the book of Psalms.
That is, the whole has a property—“consisting of 66 books”—that is not found in any of the parts.At this point, Beckwith is actually discussing something different than his initial claim. Even if Revelation stated, "And by this book I mean these sixty-six books," and then proceeded to list them, it would still be the case that the book of Revelation would not have the property consisting of sixty-six books.
In fact, it is frequently the case that the whole set of anything has a property relating to multiplicity that the parts individually lack. Thus, for example, the set of all breeds of cats has the property "consisting of X number of breeds" whereas no individual breed has that property.
To take a more topical example, "consisting of 150 psalms" is a property of the Psalter, but not of any individual psalm. This reflection of Beckwith's may be an interesting pastime for his students. On the other hand, for the reasons explained above (i.e. since it would be true even if the Bible had an explicit table of contents) it is actually irrelevant.
In other words, if the 66 books are the supreme authority on matters of belief, and the number of books is a belief, and one cannot find that belief in any of the books, then the belief that Scripture consists of 66 particular books is an extra-biblical belief, an item of theological knowledge that is prima facie non-Biblical.This has essentially been addressed above. Given the Bible, we can easily sit down and count the number of books. The fact that it is not explicitly part of the text of the Bible is actually a quite trivial point, if we are given the Bible.
What Beckwith's argument essentially asks the reader to do is to derive the belief about the number of books of Bible without the Bible. Then having taken away the Bible, Beckwith claims that the number of books can't be determined. But this is simply a game of bait and switch. Beckwith lures the reader in with a proposal to derive something from the Bible but then takes away the Bible.
Finally Beckwith asks:
Where have I gone wrong in this reasoning?To which we may reply that he went wrong when he made the switch from letting us have the Bible to taking it away from us. If we have the Bible, we can easily tell you the number of books, even if the table of contents is missing. If we don't have the Bible, we're not dealing with Sola Scriptura any more.