The Psychology of Revolution is a discussion of religious, political, mental and emotional characteristics of the leaders of revolutions, with special consideration taken from French history. Examples of revolutionary movements also include political upheavals in Portugal, China, and Turkey. Gustave Le Bon was a French social psychologist, sociologist, anthropologist, inventor, and amateur physicist. His writings incorporate theories of national traits, herd behavior and crowd psychology. He is best known for his work The Crowd: A Study of the Popular Mind.