"Runciman’s suggestion that political constitutions have a natural life cycle is reminiscent of Oswald Spengler… Like Runciman, Spengler employed a natural philosophy to organize world history into a series of quasi-biological trajectories. He viewed the situation of the West as being close to the end of a natural cycle of civilizational ossification. For Runciman this process is most advanced in polities like Greece and Japan. They are not dead but caught, he argues, in a post-historic state, paralyzed by fiscal constraints and demographic decline. …Runciman, like Spengler and Kojève, invites us to adopt a stance of disillusioned realism. If we can see the decline of democratic polities all around us and can diagnose the multiple causes of their eventual demise, that does not excuse us from the responsibility to make them work until the bitter end."
Interesting, especially that last clause. I'm interested in general in ways people/institutions try to act or plan with cycles of rise and decline in mind, rather than acting as if things are linear (whether you think progress is something inevitable or something that you can drive with certain measures) or waiting for the collapse to happen so we can have a 'clean slate'.
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[https://en.wikipedia.org/wiki/Social_cycle_theory](https://en.wikipedia.org/wiki/Social_cycle_theory)