When Herbert Marcuse's essay entitled “Repressive tolerance” was published in the mid-1960s it was trenchantly criticised because it was anti-democratic and defied the academic canon of value neutrality. Yet his argument is attracting renewed interest in the 21st century, particularly when, post 9/11, the thresholds or limits of tolerance are being contested. This article argues that Marcuse's original essay was concerned to problematise the dominant social understandings of tolerance at the time, which were more about insisting that individual citizens tolerate (...) government policy than governments encourage debate and dissent. The article shows how Marcuse attempted to demonstrate the social production of knowledge about tolerance, and how he diagnosed the social function performed by “impartiality” and “relativism”, and by “neutrality” and “objectivity”, which contributed to tolerance being repressive. In the sense that he was concerned about what counted socially as tolerance, and how it was socially defended and justified, his article can helpfully be conceived as an exercise in social epistemology. (shrink)