Charles Mackay's Memoirs of Extraordinary Popular Delusions and the Madness of Crowds, published in 1841, is the history of popular folly in three parts: "National Delusions", "Peculiar Follies", and "Philosophical Delusions". These break down into: economic bubbles, alchemy, crusades, witch-hunts, prophecies, fortune-telling, magnetisers (the influence of one's imagination in curing disease), shape of a person's hair or beard (in its influence on politics and religion), murder by poisoning, haunted houses, collective foolishness of great cities, popular admiration of great thieves, duels, and relics.

Given our current economic tribulations, the section on economic bubbles is especially pertinent. The section "tulipomania," in which tulips were the focus of massive speculation in Holland was also the focus of a section in Michael Pollan's book and documentary "Botany of Desire." This book is hilarious at parts, and is a keen insight into human nature and collective idiocy.