Spengler was educated at various universities, and gained his doctorate with a thesis on Heraclitus. His fame depends entirely on Der Untergang des Abendlandes (1918, trs. as The Decline of the West, 1932), whose oracular pessimism captured the mood of Germany after the First World War. Spengler saw history not as a linear progression, but as the flowering of a number (either nine or ten) of self-contained cultures, each with a characteristic spiritual tone, or conception of the space within which they are to act. The work was important in making a decisive break with the Hegelian concept of history as a process governed by reason. Instead Spengler’s metaphors are biological: cultures go through a self-contained process of growing, going through their seasons, and perishing. There are no historically intelligible laws to this process. His speculations have been extensively criticized as insensitive to the interactions of cultures and to the thoughts and intentions of agents involved in the process.