The Frankfurt School, from the Institute for Social Research, took up the task of choosing what parts of Marx's thought might serve to clarify social conditions which Marx himself had never seen. They drew on other schools of thought to fill in Marx's perceived omissions. Max Weber exerted a major influence, as did Freud. In the Institute's extensive (ed. Max Horkheimer, Paris 1936), Erich Fromm authored the social-psychological part. Another new member of the institute was Herbert Marcuse, who would become famous during the 1950s in the US.