The central idea of "The Fourth Turning" is that history is not linear but cyclical. Strauss and Howe identify a recurring pattern of four "turnings" that repeat every 80-100 years. Each turning has its own characteristics and societal mood, ranging from periods of growth and stability to times of upheaval and crisis. This cyclical view challenges the conventional understanding of history and offers a new framework for interpreting past events and anticipating future developments.

The authors introduce the concept of generational archetypes, suggesting that each generation falls into one of four categories: Prophet, Nomad, Hero, and Artist. These archetypes play specific roles during each turning, influencing societal behavior and outcomes. For example, Baby Boomers are seen as Prophets who lead during times of crisis, while Millennials are Heroes who come of age during these periods. Understanding these archetypes helps explain generational behaviors and interactions.

"The Fourth Turning" is notable for its predictive insights. By analyzing historical cycles and generational archetypes, Strauss and Howe make bold predictions about America's future. They argue that we are currently in the midst of a Fourth Turning, a period of crisis that will reshape society. This predictive power makes the book not just a historical analysis but also a guide for navigating future challenges, offering strategies for individuals and communities to prepare for and thrive during times of upheaval.