John Michell investigates the persistent presence of eccentric beliefs and peculiar notions throughout history and across cultures. Drawing on a wide array of historical accounts, folklore, and anecdotal evidence, Michell explores the common threads and underlying psychological or societal factors that give rise to and sustain these unconventional ideas.

This work is recognized for its deep dive into the history of unconventional thought and belief systems. Michell's approach often synthesizes disparate pieces of information, presenting a compelling narrative for those interested in the fringes of human understanding. The book is noted for its thorough research and its ability to connect seemingly unrelated phenomena.