Crest

Imagine a deep calm sea, no perturbation anywhere. Now imagine that this sea is disturbed. So now there will be crests as well as troughs.

Now the question is: can there be any crest without any trough?

That means there cannot be any good without any evil;

There cannot be any love without any hate;

There cannot be any compassion without any cruelty;

There cannot be any joy without any sorrow;

There cannot be any beauty without any ugliness;

There cannot be any justice without any injustice;