I'm afraid that would be down to my ignorance of those older liberal criticisms of decadence (unless you're talking about Marx).

I didn't mean to invoke the whole of Spengler's sprawling worldview, but just the concept of cultural growth and decline. Marxism has its baggage, too, right? Both Spengler and Marx are outdated in certain respects. But Spengler hammered on the key point: the comparison between individuals and states, and thus the inevitability of social decline.