What do financial bubbles and religious millenarianism have in common? They both involve collective delusion. When Charles Mackey wrote a book on the Madness of Crowds in the 19th century, he could not have imagined that religious and financial bubbles will continue to reappear, but as Willam Bernstein points out, the world has not gotten any saner. William Bernstein is an investment manager and the author of a number of books including, The Delusions Of Crowds: Why People Go Mad in Groups and The Birth of Plenty: How the Prosperity of the Modern World was Created. And before his work in finance, he spent more than 30 years practicing medicine. William and Greg discuss the difference between intelligence and rationality, how human nature is rooted in imitation and mimicry, and the end of the world. Gregory LaBlanc is a lifelong educator with degrees in History, PPE, Business, and Law, Greg currently teaches at Berkeley, Stanford, and HEC Paris. He has taught in multiple disciplines, from Engineering to Economics, from Biology to Business, from Psychology to Philosophy. He is the host of the unSILOed podcast. unSILOed is produced by University FM. Learn more about your ad choices. Visit megaphone.fm/adchoices Support our show by becoming a premium member! https://newbooksnetwork.supportingcast.fm/sociology