From the perspective of the reader, the covers precede the pages of a book. As we open a book, we first experience its covers and only then, upon flipping them aside, do we retrieve the bundle of pages, the book’s various quires. Subjectively speaking, the covers come first.
Objectively speaking, however, the covers come after. Historically speaking, they come last. In the development of the bound book, the covers proved to be the last constitutive element to emerge. In fact, a book doesn’t need covers to be a book. A codex is a codex by virtue of its bound pages, not its protective covering.
In the medieval West, most books didn’t have covers. In some ways, adding covers to a book was a statement of both status and survival. A book rich with covers was a book meant to last, as the covering makes the book less prone to loss, decay and destruction. Only a fraction of the books (i.e. bound books) produced during the Middle Ages has been preserved, and that is partially due to the fact that most of these books never featured any covers. Many of them weren’t even sown together, but were allowed to exist as quires in a bundle, forever on the cusp of binding, but not quite making it there.