Max Horkheimer was a German philosopher and sociologist best known for his role in developing critical theory as director of the Institute for Social Research, commonly associated with the Frankfurt School.
Advancing a materialist theory of reason and society, Horkheimer analyzed the rise of instrumental reason, the erosion of the concept of truth, the decline of individual autonomy, the social-psychological roots of authoritarianism, and the reproduction of domination under modern capitalism. These concerns became fundamental to critical theory.
His most influential works include Eclipse of Reason (1947), Dialectic of Enlightenment (1947, with Theodor W. Adorno), and a series of foundational essays written in the 1930s for the Zeitschrift für Sozialforschung, later collected in Between Philosophy and Social Science and Critical Theory: Selected Essays. He also composed aphoristic reflections between the late 1920s and the 1960s, published posthumously as Dämmerung (Dawn and Decline). As director of the Institute, Horkheimer planned, supported, and made possible many other significant works.