London: Richard Bentley, 1841. In three volumes. First edition. 8vo. vi, (ii), 400; (iv), 406; (iv), 404 pp; each volume lacking half-titles and rear ads. Illustrated with engraved portrait frontispiece in each volume, and two engraved portrait plates in third volume. Full polished tan calf, stamped in gilt, green and red morocco spine labels; first and third volumes, all boards detached, but present; second volume front board detached, but present, rear boards starting on same; spines dry and chipped on each volume, extremities rubbed on each volume; by J. Larkins for E.W. Stibbs; frontispiece in first volume lightly foxed and darkened; dampstaining in upper gutter of frontispiece in third volume; with the book-plate of physician and historian George Clinton Fairchild Williams (1857-1933) on front paste-down of each volume.

An early study of crowd psychology, Mackay's popular work is divded into three broad categories: "National Delusions", "Peculiar Follies", and "Philosophical Delusions," and discusses a wide range of subjects including the Crusades, witch-hunts, alchemy, poltergeists, and the political and religious influence on hair and beards. The chapters on economic bubbles and financial mania has proven especially influential and is now considered a key text in the field of economics.