For years I taught children about the various cycles of nature.
The water cycle, I told them, involved the movement of water in its various forms–the rain came from clouds, which were simply vaporized water that had risen from lakes and rivers and the ocean.
I explained to them how the rock cycle involved magma erupting from the earth and cooling into rocks, some of which ended up in the ocean. Some of these, I said, were pressed into sedimentary rock which, due to pressure and heat, could become metamorphic rock. Due to the earth’s movement rock could be buried and become magma–and the cycle would begin anew.
They learned that on mountaintops were the fossilized remains of sea creatures; those mountaintops had once been the ocean floor.
Nature is in flux. Life is characterized by movement. There is no stillness, even if there appears to be on the surface. History is characterized by cycles; phenomena occur in waves. Permanence and certainty are unknown.
Never in history has there been permanence in human affairs, either. There never can or will be.