US, Nov. 9 -- Two American historians, William Strauss and Neil Howe, wrote The Fourth Turning in 1997. Since then, it has been used as a manual of how to cope with uncertain times. The book claims that all of Anglo-American history follows a recurring pattern, in which history repeats itself in eighty-year cycles. In each eighty-year cycle, history is divided into four distinct periods, or 'turnings', which last about twenty years each.

These periods start with a High (of faith in institutions), move to an Awakening (of consciousness and morals), then to an Unraveling (a breakdown of confidence), and finish with a Crisis (a total collapse of the old order). This framework accounts for the American Revolution, the Civil War and the Seco...