Pierre Clastres was a French anthropologist and ethnologist. He is best known for his contributions to the field of political anthropology, with his fieldwork among the Guayaki in Paraguay and his theory of stateless societies. An anarchist seeking an alternative to the hierarchized Western societies, he mostly researched indigenous people in which the power was not considered coercive and chiefs were powerless.
With a background in literature and philosophy, Clastres started studying anthropology with Claude Lévi-Strauss and Alfred Métraux in the 1950s. Between 1963 and 1974 he traveled five times to South America to do fieldwork among the Guaraní, the Chulupi, and the Yanomami. Clastres mostly published essays and, because of his premature death, his work was unfinished and scattered. His signature work is the essay collection Society Against the State (1974) and his bibliography also includes Chronicle of the Guayaki Indians (1972), Le Grand Parler (1974), and Archeology of Violence (1980).