New Delhi, June 4 -- Charles Mackay's "Extraordinary Popular Delusions and the Madness of Crowds" (1841) is reviled by historians and revered among traders. The book is best known for its colourful passages on Tulip mania in the 17th century and the South Sea bubble in the 18th. But those wanting to understand business in the 21st should instead turn to Mackay's chapter on the "epidemic terror of the end of the world".

Apocalyptic thinking is the strongest impulse in American capitalism today. Elon Musk, a character who could be straight from Mackay's pages, will soon float SpaceX, a rocket company whose professed mission is to avert existential threats to humanity by establishing a colony on Mars. Mr Musk is America's richest capitalist...