It is a wave however, rather than a circle. There are oscillations, back and fourth between all sorts of things. It is inevitable because the competing ideas and systems are oscillating, all the way down. Nature is not perfectly in sync, and that is indeed what makes things interesting.
Usually the most apt metaphor is a spiral. We’ve gone round in a big circle, it feels like we’re back in the same place, except everything is completely different due to movement in a dimension which we didn’t even perceive.
And, well, you know, “words”... whatever works :-D
