Paul-Michel Foucault was a French historian of ideas and philosopher, who was also an author, literary critic, political activist, and teacher. Foucault's theories primarily addressed the relationships between power, knowledge and liberty, and he analyzed how they are used as a form of social control through multiple institutions. Though often cited as a structuralist and postmodernist, Foucault rejected these labels and sought to critique authority without limits on himself. His thought has influenced academics within a large number of contrasting areas of study, with this especially including those working in anthropology, communication studies, criminology, cultural studies, feminism, literary theory, psychology, and sociology. His efforts against homophobia and racial prejudice as well as against other ideological doctrines have also shaped research into critical theory and Marxism–Leninism alongside other topics.