
The idea that history is cyclical in some sense is an ancient one found in many cultures, not least the ancient Greeks, harbingers of modern science. But it's only in the last three decades — since Jack Goldstone's "Revolution and Rebellion in the Early Modern World" was published in 1991 — that this ancient idea has been given a testable scientific foundation, based on relationships between the general population, elites and the state, and how they vary over time with demographic changes.
Turchin has played a leading role in refining and testing this model. His 2009 book "Secular Cycles," co-authored with Sergey Nefedov, used Goldstone's model to examine England, France and Russia during the medieval and early modern periods, as well as the Roman Republic and Roman Empire. His widely read and 2016 workbook "Ages of Discord" (Salon review here) did the same for American history.