As philosopher, dramatist, novelist, critic and moralist Sartre's major preoccupation was, throughout his life, always the same – freedom, its implications and its obstacles. It is a critical cliché – and Sartre himself contributed to its dissemination – to view the progression of his thought as moving away from a conception of absolute freedom towards a mature position which takes into account the constraints and conditioning of the external world. But such a picture is over-simple. Sartre was concerned from the outset with the relation between freedom and non-freedom, whether the latter be seen in terms of destiny or alienation or simply human finitude: the inescapable conditions of life, that is to say death, work, language. The early Sartre (for convenience, up to the mid-1950s) is concerned primarily with the individual, his situation and his facticity; the later Sartre with society, ‘pre-destination’ and the ‘practico-inert’ – in all cases it is against a background of inalienable ontological liberty that these limiting concepts operate. Depending on the perspective chosen, philosophical or political, Sartre may be viewed as an optimist converted to pessimism (this picture of his evolution focusses on individual freedom and its apparent progressive erosion), or as a pessimist converted to optimism (this view centres rather on Sartre's early passive descriptions of freely alienated liberty and his later activist stance which strove to ‘change the world’).