This is a power-point presentation on a theory of history developed by Indian philosopher PR Sarkar. The main idea is that each era of history is dominated by a particular mentality embodied by a ruling class. There is a rotation of these classes in history, and the ups and downs of this cycle can be corrected by the emergence of spiritual revolutionaries, known as Sadvipras.

This presentation is based on Human Society Part 2 by PR Sarkar.