Could you tell night from day? No, I regard all such distinctions as logically impossible.
There is nothing peranent except change.
There is harmony in the tension of opposites, as in the case of the bow and lyre.
You cannot step into the same river twice.
All things flow, nothing abides.
There is nothing permanent except change. [Therefore enjoy what good you have while you have it and endure and outlast what bad you can't cure immediately]