There’s a quote attributed to EB White that goes, “Genius is more often found in a cracked pot than in a whole one.” The list below appears to confirm that, with stories about geniuses who disappeared, geniuses who vanished, and, yes, some geniuses who seem to be some flavor of what people used to call, insensitively, “crazy.” But the plural of anecdote, as they say, isn’t data. These so-called mad geniuses aren’t a homogeneous group of crackpots. Some of these geniuses went into hiding for perfectly sensible reasons, such as to flee the Gestapo or avoid pushy and privacy-invading press.