A Revisionist Marxist social theory developed in Frankfurt, Germany in the 1930s. It sought to explain the failure of Marxism to bring about a social revolution, to challenge the Base-Superstructure model promoted by Marx and conduct wide-ranging research into social forms and processes in order develop more successful ways of bringing about social transformation.  Its chief characteristic is its challenge to received notions of reality, seeking to demonstrate the ways in which our conceptions are socially constructed. Critcal theory is reflexive that is, it is aware that the “reality” that we experience “out there” does not exist independently of ideology, but that it is shaped (along with our perceptions of it) by forces of power and hegemony that have a human agency. See: Held, D., Introduction to Critical Theory, University of California Press, 1980.