You may think you know everything about Greek comedy, but a new book, Greek Laughter, by Stephen Halliwell, tells you how it was really done. Reviewed by Mary Beard in the Times of London, the book describes the central role of comedy in Greece and analyzes ancient correspondence for clues. While it was hard to please the Greeks, they were occasionally afflicted with a violent case of the giggles. The philosopher Chrysippus and the dramatist Polemon both keeled over after finding a donkey munching on figs that had been prepared for their own meal. Caligula, on the other hand, loved pranks, and placed inflated pillows (perhaps the original whoopee cushion) on his guests’ seats. He laughed as they gradually sank under the table as the air deflated. Beard thinks the book could have expanded on the causes (instead of just the theories) behind Greek laugher, to help us stone-faced moderners understand a little more about our predecessors. Laughter may be cheap, but this book is not: it’s going for $60 on Amazon.