Max Horkheimer was a German philosopher and social scientist. He was the founder of critical theory. Horkheimer's intellectual sources included the philosophies of the French Enlightenment, Immanuel Kant, Georg Wilhelm Friedrich Hegel, Friedrich Nietzsche, and Karl Marx. He also drew on ideas from sociology and psychoanalysis. Between 1931 and 1958, Horkheimer served as the director of the Institute of Social Research of Frankfurt am Main, Germany (also known as the Frankfurt School). The 1933 National Socialist takeover forced Horkheimer, who was of Jewish origin, to immigrate to America, where the institute was temporarily set up. He returned to Germany in 1948. Horkheimer ranks as one of Europe's most prominent twentieth-century social thinkers. His work has shaped the projects of Theodor Adorno, Herbert Marcuse, Jürgen Habermas, ...