Paul Lafargue was a Cuban-born French revolutionary Marxist socialist, political writer, economist, journalist, literary critic, and activist; he was Karl Marx's son-in-law, having married his second daughter, Laura. His best known work is The Right to Be Lazy. Born in Cuba to French and Creole parents, Lafargue spent most of his life in France, with periods in England and Spain. At the age of 69, he and 66-year-old Laura died together by a suicide pact.

Karl Marx was a German-born philosopher, economist, political theorist, historian, sociologist, journalist, and revolutionary socialist. His best-known works are the 1848 pamphlet The Communist Manifesto and the three-volume Das Kapital (1867–1894); the latter employs his critical approach of historical materialism in an analysis of capitalism and is the culmination of his intellectual efforts. Marx's ideas and theories and their subsequent development, collectively known as Marxism, have exerted enormous influence on modern intellectual, economic and political history.