Critical theory is a type of social theory oriented toward critiquing and changing society as a whole, in contrast to traditional theory oriented only to understanding or explaining it. Critical theories aim to dig beneath the surface of social life and uncover the assumptions that keep us from a full and true understanding of how the world works. It was developed by a group of sociologists at the University of Frankfurt in Germany who referred to themselves as The Frankfurt School, including Jurgen Habermas, Herbert Marcuse, Walter Benjamin, Max Horkheimer, and Theodor Adorno.
Two core concepts of critical theory are that it should be directed at the totality of society in its historical specificity (how it came to be at a specific point in time) and that it should improve the understanding of society by integrating all the major social sciences, including geography, economics, sociology, history, political science, anthropology, and psychology.
According to Max Horkheimer, Director of the Frankfurt School's Institute for Social Research, a critical theory is adequate only if it meets three criteria: it must be explanatory, practical, and normative, all at the same time. That is, it must explain what is wrong with current social reality, identify the actors to change it, and provide both clear norms for criticism and achievable practical goals for social transformation.
Johnson, A. (1995). The Blackwell Dictionary of Sociology. Malden, Massachusetts: Blackwell Publishers.