Extraordinary Popular Delusions and the Madness of Crowds

The first volume begins with a discussion of three economic bubbles, or financial manias: the South Sea Company bubble of 1711–1720, the Mississippi Company bubble of 1719–1720, and the Dutch tulip mania of the early seventeenth century. According to Mackay, during this bubble, speculators from all walks of life bought and sold tulip bulbs and had even declared futures contracts on them. Allegedly, some tulip bulb varieties briefly became the most expensive objects in the world during 1637.[6] Mackay's accounts are enlivened by colorful, comedic anecdotes, such as the Parisian hunchback who supposedly profited by renting out his hump as a writing desk during the height of the mania surrounding the Mississippi Company.

Two modern researchers, Peter Garber and Anne Goldgar, independently conclude that Mackay greatly exaggerated the scale and effects of the Tulip bubble,[7] and Mike Dash, in his modern popular history of the alleged bubble, notes that he believes the importance and extent of the tulip mania were overstated.[8]

• The Mississippi Scheme
• The South Sea Bubble
• The Tulip Mania
• Relics
• Modern Prophecies
• Popular Admiration for Great Thieves (cf hybristophilia)
• Influence of Politics and Religion on the Hair and Beard
• Duels and Ordeals
• The Love of the Marvellous and the Disbelief of the True
• Popular Follies in Great Cities
• Old Price Riots
• The Thugs, or Phansigars

Mackay describes the history of the Crusades as a kind of mania of the Middle Ages, precipitated by the pilgrimages of Europeans to the Holy Land. Mackay is generally unsympathetic to the Crusaders, whom he compares unfavourably to the superior civilisation of Asia: "Europe expended millions of her treasures, and the blood of two millions of her children; and a handful of quarrelsome knights retained possession of the Kingdom of Jerusalem for about one hundred years!"

Witch trials in 16th- and 17th-century Western Europe are the primary focus of the "Witch Mania" section of the book, which asserts that this was a time when ill fortune was likely to be attributed to supernatural causes. Mackay notes that many of these cases were initiated as a way of settling scores among neighbors or associates, and that extremely low standards of evidence were applied to most of these trials. Mackay claims that "thousands upon thousands" of people were executed as witches over two and a half centuries, with the largest numbers killed in Germany.

• The Crusades
• The Witch Mania
• The Slow Poisoners
• Haunted Houses

The section on alchemysts focuses primarily on efforts to turn base metals into gold. Mackay notes that many of these practitioners were themselves deluded, convinced that these feats could be performed if they discovered the correct old recipe or stumbled upon the right combination of ingredients. Although alchemists gained money from their sponsors, mainly noblemen, he notes that the belief in alchemy by sponsors could be hazardous to its practitioners, as it wasn't rare for an unscrupulous noble to imprison a supposed alchemist until he could produce gold.

• Book I: The Alchemysts
• Book II: Fortune Telling
• Book III: The Magnetisers