After a long period of neglect, the works of Edgar Zilsel (1891–1944) experienced a late renaissance at a Vienna Symposion in 1991. The book under review contains a selection of nine essays written bei Zilsel, all but one published between 1929 and 1933 in the social-democratic journal of interwar Austria, Der Kampf The editor presents Zilsel as an original sociologist of science and knowledge, as a philosopher and an advocate of scientific socialism, as a naturalistic methodologist of the social sciences, and finally as a polemical, but analytically profound critic of ideologies.