Mencius (372-298 BC) was one of the greatest Chinese philosophers, focusing on political theory and practice. Mencius, like Confucius, believed that rulers were divinely placed in order to guarantee peace and order among the people they rule. Unlike Confucius, Mencius believed that if a ruler failed to bring peace and order about, then the people could be absolved of all loyalty to that ruler and were justified to revolt. D. C. Lau is a Professor at the University of Hong Kong.