This, the final volume of the Cambridge History of Political Thought, attempts to provide an overview of the main currents of twentieth-century social and political thinking. It is difficult to narrate the history of political thought in any period; but to attempt to survey the history of twentieth-century political theorising in all its variety and diversity presents particular difficulties, if only because the century just ended was marked by a pervasive scepticism about the ways in which histories are narrated and an acute awareness of the many and alternative ways in which they may be constructed. The influence of Marx and Freud, amongst other theorists, has fostered ‘the hermeneutics of suspicion’, according to which nothing is ever as it appears to be, and this suspicion extends to the writing of histories, including the present one. For a start, suspicions about ideological bias are bound to arise, and these are only compounded because our contributors are narrating the history of their own time.