In 1950, Theodor W. Adorno published an essay entitled "Spengler after the Downfall" (in German: Spengler nach dem Untergang)[17] to commemorate what would have been Spengler's 70th birthday. Adorno reassessed Spengler's thesis three decades after it had been put forth, in light of the catastrophic destruction of Nazi Germany (although Spengler had not meant "Untergang" in a cataclysmic sense, this was how most authors after WWII interpreted it).
As a member of the Frankfurt School of Marxist critical theory, Adorno's professed project in this essay was to "turn (Spengler's) reactionary ideas toward progressive ends." Thus Adorno conceded that Spengler's insights were often more profound than those of his more liberal contemporaries, and his predictions more far-reaching. Adorno sees the rise of the Nazis as confirmation of Spengler's ideas about "Caesarism" and the triumph of force-politics over the market. Adorno also draws parallels between Spengler's critique of Enlightenment and his own analysis of Enlightenment's self-destructive tendencies. However, Adorno also criticizes Spengler for an overly deterministic view of history, ignoring the unpredictable role that human initiative plays at all times. He quotes the contemporary Austrian poet Georg Trakl: "How sickly seem everything that grows" (from the poem "Heiterer Frühling") to illustrate that decay contains new opportunities for renewal. Adorno also criticizes Spengler's use of language, which overly relies on fetishistic terms like "Soul", "Blood" and "Destiny."