The typical science fiction writer will take a concept he finds interesting—say, nanotechnology—explore and build an architecture of plot around the theme and if it all goes well something entertaining will be the end product. Not so with Neal Stephenson. Everything he has written is a heady mix of half a dozen complex ideas: cryptography, currency, philosophy, the history of science, memetics, computer viruses, and so on. (Stephenson brought our present meaning for the word “avatar” into common usage.) If he weren’t often seen in public, it would be possible to argue that Stephenson was some sort of composite, a synthesis of assorted futurists, historians, philosophers, and fiction writers, all writing as a team.