Simone de Beauvoir presents a considerable challenge to anyone attempting to identify the crucial influences in her life and work since in a very important sense they can be summarised by naming Jean-Paul Sartre. This is not, as it might first appear, the suggestion that this brilliant (and productive) woman writer only achieved prominence because of a relationship with a man. This was far from the case (and there is some evidence to lead us to speculate on what de Beauvoir gave to Sartre rather than the reverse) but what we have to acknowledge is the close association (both social and intellectual) between these two figures and the dialogue between them that was so crucial to both. In biographical terms, there is little doubt that Sartre led de Beauvoir away from idealist philosophy and towards existentialism; at the same time de Beauvoir’s work was organised around (and here the idea of dialogue is central) the working out, in both fiction and non-fiction, of Sartre’s ideas on morality and the limits of personal responsibility. Both individuals, it must be emphasised, have to be located firmly within European modernism. In terms of both philosophy, and politics, de Beauvoir and Sartre entirely endorsed, for most of their adult and working lives, the Enlightenment’s expectations of the rule, indeed the possibilities, of the rational. In de Beauvoir’s case this discourse made her profoundly sceptical of all religions and of psychoanalysis: the world, as far as she was concerned, could be rationally understood and rationally organised. That emotional life did not always lend itself to such rational principles was a constant theme of de Beauvoir’s fiction: from her first published novel She Came to Stay she was preoccupied with the problems of subjectivity and the irrational.1