This publication provides an insight into one of the 20th century's most underrated (anti-)art movements. The rather shadowy existence led by the Situationists and their Lettrist predecessors in the annals of the post-war avant-garde, and the indeterminacy of their legacy are largely of their own making: their agenda of political radicalism and negativity included a strict refusal to co-operate with the "bourgeois" mass media and enter the wider intellectual and political debate. * * Published in collaboration with Centraal Museum, Utrecht, and Museum Tinguely, Basel.