Knowing the cycles of history is nothing more than understanding the yin-yang of the universe; being able to spot peaks and troughs; when a field or industry or stock or mindset is out of balance. In investing this is called contrary opinion theory.
When opinion is too far in one direction-- 99% agreement-- then it has nowhere to go but the other direction. In the face of extreme opinion-- or extreme stagnation-- it will flip over, almost overnight. This is called revolution.
Literature is at this reversal point.