Lack of technological progress in late Roman Empire

[Eleatic Guest]

Another invention of late Roman times - who would have thought that - is the book! Apparently, the Christian element was decisive in its spread and ultimate replacement of the roll.

During the first two centuries AD, only the roll was used for literary works. Martial (84-86 AD) is the first to mention a parchment codex.[4] He points out that it is more convenient for a traveler and how much space it saves in a library. He even gives the name and address of a publisher where one may purchase texts in codex form. However, it seems that this experiment failed, as there are no further references to the codex in this context for a whole century. In about 220 AD, lawyers began to concern themselves with the definitions for various kinds of books. In the Digest of Ulpian we find that the codex is an established and acceptable kind of book, but it was certainly not fashionable.[5] Indeed, the extant evidence from Egypt of Greek literary and scientific texts indicates that only by 300 AD did the codex achieve parity with the roll. However, if we examine the extant Christian works, a very different picture emerges. Of the surviving 172 Biblical texts that can be dated before 400 AD, 158 are in the form of the codex and only fourteen are in the form of the roll. All eleven of the second-century books are papyrus codices. As far as we know the early Bible was always written in the codex form. Of the non-Biblical Christian works, eighty-three are codices and thirty-five are rolls. Clearly the adoption of the codex was associated with the rise of Christianity.

http://web.ku.edu/~bookhist/medbook1.html