"Stop me if you've heard this," Jim Holt's new history and philosophy of jokes, isn't a topnotch book. It jumps around, from Palamedes to Sarah Silverman, and the closest it comes to a big idea is that jokes "come and go." But there are at least 10 pages (28–38) that everyone should read. They're about Gershon Legman, a "self-taught scholar of the dirty joke," who claimed to coin the phrase "Make Love, Not War," invent the vibrating dildo and introduce origami to the West. (He wasn't kidding.) Born in Pennsylvania in 1917, Legman's life has a gripping, Forrest Gump-like quality to it. He moved to New York after high school, and found work as an erotic-book hunter for Alfred Kinsey, before breaking away to pursue his true calling. By his death in 1999, he'd amassed one of the world's largest dirty-joke collections, more than 60,000 variants filed away on index cards under amusing headers like THE BIG INCH and ZOO-PHILY. Holt's book isn't quite that funny, but the pages on Legman are seriously worth the read.