It is now thirty years ago since Sartre died – it was on 19 April 1980 that Simone de Beauvoir in the last of existentialist gestures threw a white rose on Sartre’s coffin. A recent, somewhat sensationalist, biography of the couple by Carole Seymour-Jones bears the title A Dangerous Liaison, referring to the open marriage between the two, into which ‘contingent loves’ were allowed insofar as they did not interfere with the ‘essential’ commitment of the one to the other. However successful this project may have been – on Seymour-Jones’s account, not very – my concern here is with another kind of dangerous liaison, that between literature and philosophy, and with what is involved in the project of being true to both.

Sartre is virtually unique in being equally acclaimed for his literary work and for his philosophical work. One suspects that if his novels such as Nausea and plays such as Huis Clos are more widely read than Being and Nothingness this reflects the fact that, even in Paris, more people find fiction to their taste than works of philosophy. But nonetheless there is no such rigid demarcation between the two in Sartre. His work is all of a piece: he is exploring his philosophical ideas first in one form, then in another. In Sartre there is an essential relationship between literature and philosophy.

Compare this with the case of Bertrand Russell who wrote many works of philosophy and many works on politics – ...