I am a philosopher, economist, historian, sociologist, political theorist, journalist, critic of political economy, and socialist revolutionary. The 1848 pamphlet The Communist Manifesto and the four-volume Das Kapital (1867–1883) are my best-known titles. My political and philosophical thought enormously influenced subsequent intellectual, economic, and political history. My name has been used as an adjective, a noun, and a school of social theory.