Jean-Francois Lyotard was one of the most influential European thinkers in recent decades. He was a leading participant in debates about post-modernism and the decline of Marxism, and he made important contributions to ethics, aesthetics and political philosophy. In this authoritative introduction, Williams tracks the development of Lyotard's thought from his early writings on the libidinal economy to his more recent work on the post-modern condition. Williams argues that despite the wide-ranging character of Lyotard's writings, they are animated by a long-standing concern to develop a new theory of political action. Lyotard's productive use of avant-garde art and the aesthetics of the sublime are interpreted within this context. In the final chapters some of the main criticisms that have been levelled at Lyotard's work are outlined and assessed. A challenging but also accessible book, it will be welcomed by students and researchers in continental philosophy, literary theory and the humanities generally.