Jean-Paul Sartre famously wrote, nearly 50 years ago, that Marxism "remains the philosophy of our time. We cannot go beyond it." In his critic Raymond Aron's words, Marxism was for Sartre the "insurpassable [or, in other translations: unsuperable] philosophy of our time.¹" Taken in context, Sartre's pronouncement was at once descriptive and prescriptive: it was, according to him, neither objectively possible for the philosopher to leave the confines of Marxism, nor ethically permissible to attempt to do so.