The 1967 ‘Summer of Love’ brought all sorts of unusual people and events to London but perhaps nothing so extraordinary as the Congress on the Dialectics of Liberation. The congress, organized by the American ‘anti-psychiatrist’ Joe Berke, with help from Leon Redler, R.D. Laing, David Cooper, and a host of students, ex-students, psychiatric ‘patients’, and secretaries, took place at the Roundhouse in Chalk Farm Road over two weeks during July, and was designed to ‘demystify human violence in all its forms, the social systems from which it emanates, and to explore new forms of action.’ But that bald summary of the purpose of the congress, accurate as it is, hardly does justice to its immediate achievements or to its long-term significance. Mingling with the many then famous speakers: Allen Ginsberg, Herbert Marcuse, Paul Goodman were many younger people who arrived with their own ideas and who themselves went onto distinguished and influential careers in the arts, politics and academia.