 Marxism is not just any hypothesis that might be replaced tomorrow by some other. It is the simple statement of those conditions without which there would be neither any humanism, in the sense of a mutual relation between men, nor any rationality in history. In this sense Marxism is not a philosophy of history; it is the philosophy of history and to renounce it is to dig the grave of Reason in history. (HT: 266/153) 