An illuminating exploration of reference books through time and across cultures, from the Babylonian Code of Hammurabi to Wikipedia.
Knowledge is of two kinds, said Samuel Johnson in 1775. We know a subject ourselves, or we know where we can find information upon it. Today we think of Wikipedia as the source of all information, the ultimate reference. Yet it is just the latest in a long line of aggregated knowledge-reference works that have shaped the way we've seen the world for centuries.