In order to be interesting, a nonfiction book must flirt with—but NEVER cross—the Textbook Axis.

I was recently thinking about Scott McCloud’s seminal work on how comics work: Understanding Comics. It’s a comic book that explains all sort of stuff about comics: the tradeoff between a cartoony style and a realistic style; how panels are arranged for effect; the types of panels; the history of comics—everything you never thought about while you read …