Critical theory is a school of thought that stresses the reflective assessment and critique of society and culture by applying knowledge from the social sciences and the humanities. As a term, critical theory has two meanings with different origins and histories: the first originated in sociology and the second originated in literary criticism, whereby it is used and applied as an umbrella term that can describe a theory founded upon critique; thus, the theorist Max Horkheimer described a theory as critical insofar as it seeks "to liberate human beings from the circumstances that enslave them."^[1]

In philosophy, the term critical theory describes the neo-Marxist philosophy of the Frankfurt School, which was developed in Germany in the 1930s. Frankfurt theorists drew on the critical methods of Karl Marx and Sigmund Freud. Critical theory maintains that ideology is the principal obstacle to human liberation.^[2]Critical theory was established as a school of thought primarily by five Frankfurt School theoreticians: Herbert Marcuse, Theodor Adorno, Max Horkheimer,Walter Benjamin, and Erich Fromm. Modern critical theory has been influenced by György Lukács and Antonio Gramsci as well as the second generation Frankfurt School scholars, including Jürgen Habermas. In Habermas's work, critical theory transcended its theoretic roots in German idealism, and progressed closer to American pragmatism. Concern for social "base and superstructure" is one of the remaining Marxist philosophic concepts in much of the contemporary critical theory.^[3]

While critical theorists have been frequently defined as Marxist intellectuals^[4] their tendency to denounce some Marxist concepts and to combine Marxian analysis with other sociologic and philosophic traditions has been labeled as revisionism by Classical, Orthodox, and Analytical Marxists, and by Marxist-Leninist philosophers. Martin Jay has stated that the first generation of critical theory is best understood as not promoting a specific philosophical agenda or a specific ideology, but as "a gadfly of other systems".^[5]

The Frankfurt School (German: Frankfurter Schule) is a school of neo-Marxist interdisciplinary social theory^[1] associated in part with the Institute for Social Research at the Goethe University in Frankfurt, Germany. The school initially consisted of dissident Marxists who believed that some of Marx's followers had come to parrot a narrow selection of Marx's ideas, usually in defense of orthodox Communist parties. Meanwhile, many of these theorists believed that traditional Marxist theory could not adequately explain the turbulent and unexpected development of capitalist societies in the twentieth century. Critical of both capitalism and Soviet socialism, their writings pointed to the possibility of an alternative path to social development.^[2]

Although sometimes only loosely affiliated, Frankfurt School theorists spoke with a common paradigm in mind, thus sharing the same assumptions and being preoccupied with similar questions.^[3] In order to fill in the perceived omissions of traditional Marxism, they sought to draw answers from other schools of thought, hence using the insights of antipositivist sociology, psychoanalysis, existential philosophy, and other disciplines.^[1] The school's main figures sought to learn from and synthesize the works of such varied thinkers as Kant, Hegel, Marx, Freud, Weber and Lukács.^[4]

Following Marx, they were concerned with the conditions that allow for social change and the establishment of rational institutions.^[5] Their emphasis on the "critical" component of theory was derived significantly from their attempt to overcome the limits of positivism, materialism and determinism by returning to Kant's critical philosophy and its successors in German idealism, principally Hegel's philosophy, with its emphasis on dialectic and contradiction as inherent properties of reality.

Since the 1960s, Frankfurt School critical theory has increasingly been guided by Jürgen Habermas's work on communicative reason,^[6][7] linguistic intersubjectivityand what Habermas calls "the philosophical discourse of modernity".^[8] More recently, critical theorists such as Raymond Geuss and Nikolas Kompridis have voiced opposition to Habermas, claiming that he has undermined the aspirations for social change which originally gave purpose to critical theory's various projects—for example the problem of what reason should mean, the analysis and enlargement of "conditions of possibility" for social emancipation, and the critique of moderncapitalism.^[9]