The codex — multiple sheets of paper or parchment sewn together — the book as we know it, has been around for 2,000 years. It made reading easier; you needn’t use both hands to unroll and roll a scroll. You could go quickly to any page; numbering made that even easier.

Over the years, all sorts of additional reading tools have been built into books. Heads and subheads make information more accessible, as in the Bible: even today, when we want to characterize precise information we speak of “giving chapter and verse.”

Once books were divided up, it made sense to list the contents; to construct a table. And when there came to be lots of books, stacked up and then shelved in rows, a title on the spine made life easier.

Prefaces, introductions, and acknowledgements help us to understand authors, and decide whether to read their books. Plot summaries, praise from famous women or men; often they’re an indication of whom authors consulted, which libraries they ransacked, how authorship affected their homes and families.

Publication data: when, where, by whom. An appropriate date and respectable publisher tells us something, as, when provided, does cataloging information: how experts categorize a book, and where to find similar works on library shelves.

Footnotes do a lot of work. They tell us where an author got his information, his ideas; and how hard he worked, perhaps. Some authors comment incisively on their sources. Footnotes also tell us where to go next, beyond the author’s words. Here, long before computing, lie the origins of hypertext: one text leads to others. Slowly, because one couldn’t just click, but scholars have always assembled the books they need most often.

The index is another great tool. (There’s a new book by Duncan: “Index, a history of the…”.) And its alphabetical arrangement leads toward whole books that are reading tools: most obviously, dictionaries.

Digital media have adopted and adapted some of these reading tools; they developed over centuries, and new ones take time. The big problem with new media is permanence: remember magnetic tape, or floppy discs? We can hope that flash drives and clouds will last out this millennium. Meanwhile, we still have books.

For David R. Jones, books and their tools matter.