Olin Wright (1947-2019) was Vilas Distinguished Professor of Sociology at the University of Wisconsin. Author of many books, including Clase, crisis y Estado (Siglo XXI de España, 1983) and Clases (Siglo XXI de España, 1994), he also directed Real Utopias, a project initiated in 1991 that explores a wide range of proposals and models for radical social change.