It is just a bit tiresome to have to make the same points over and over again about early Christians and the codex, but it seems necessary. I laid out some matters in an earlier posting here, for example. So in this posting I will simply list some key points briefly.

Christian preference for the codex is readily demonstrable from data that can be obtained open-access from the Leuven Database of Ancient Books (here).

This Christian preference was especially, notably strong for copies of texts used/read as scripture (copies of Old Testament writings, and Christian texts so used, over 95% codices). For other texts (theological treatises, and other kinds), early Christians were comparatively more ready to use the bookroll (about 1/3 of copies of these sorts of texts are on bookrolls).

Modern references to the supposedly “obvious” advantages of the codex aren’t matched by any statements of Roman-era writers. If the advantages of the codex were so obvious, why were the early Christians the only ones to perceive them? It seems counter-intuitive to me. The only ancient comments about the usefulness of the codex that I know are in Martial’s Epigrams, where he mentions a local bookseller who produced small codex-copies of his poetry, which he commends for taking on your travels. We have examples of such small/miniature codices, and equivalent bookrolls too. But the early Christian codices aren’t typically such small/miniature ones. So, the Christian preference for the codex doesn’t seem to be explained as deriving from a preference for pocket-sized editions.

And the supposedly “obvious” superiority of the codex for finding particular passages in larger literary texts seems to me shaped too much by our greater ease with the leaf-book and our lack of ease with the bookroll. Ancient Jews likewise pored over their sacred texts in minute detail and made reference to specific passages, but steadfastly preferred the bookroll.

Likewise, speculations about the relationship of the codex and the emerging Christian canon are typically misinformed and so erroneous. The NT canon isn’t the product of preference for the codex. In about the same period, Judaism established a canon, all the while firmly preferring bookrolls for their scriptures. And the earliest fragments of codices seems to be from single-text ones, such as P52, a remnant of a copy of GJohn.

Well into the 3rd century, Christians were experimenting with developing ways to construct codices to accommodate multiple texts, such as P46 (Chester Beatty Library & University of Michigan), a copy of Pauline epistles, or P45 (Chester Beatty Library), a copy of the four Gospels and Acts. That they were still working at how to construct codices to accommodate multiple works shows that the collecting of writings came first and the concern to copy multiple texts in one book came subsequently. In short, the codex didn’t shape the emerging canon; instead, the emerging canon drove and shaped the development of codex technology among Christians. And, by the way, Christians of the 2nd/3rd centuries seem to have been at the “leading edge” in codex technology.

So, the big question: Why did early Christians so firmly and concertedly opt for the codex? They left us no comments on the matter, so we scholars have to devise the best guesses that we can. Personally, I side with the great papyrologist, Colin H. Roberts, in thinking that it was likely deliberate, to give early Christian copies of texts a marked form that distinguished them from the larger book-culture of the time.