In their book The Fourth Turning, William Strauss and Neil Howe argue that American history has moved in cycles that last roughly as long as a human lifetime, within which are four distinct two-decade eras, or turnings. They say that although we think our time is unique, the way people feel today—or at any time—echo the feelings and attitudes and behaviors of past times. Mark Twain’s quote “History doesn’t repeat itself, but it often rhymes,” is a good summation.
These four turnings are like seasons. The first is spring, the birth of a new order, followed by