The codex is built for nonlinear reading – not the way a Web surfer does it, aimlessly questing from document to document, but the way a deep reader does it, navigating the network of internal connections that exists within a single rich document like a novel. Indeed, the codex isn’t just another format, it’s the one for which the novel is optimized. The contemporary novel’s dense, layered language took root and grew in the codex, and it demands the kind of navigation that only the codex provides.

—Lev Grossman