Civilizations normally go through three stages; Barbaric, Vigorous and Decadent. It’s easy to find examples of barbaric and decadent civilizations.
We can find all the barbaric civilizations to suit an entire faculty’s worth of anthropologists in the Middle East. And then back home we can see the decadent civilization that employs their kind to bemoan the West. Vigorous is what America used to be when it was moving west, producing at record rates and becoming a world power.