Heraclitus of Ephesus taught that the world is an ever-living fire, kindled and quenched in measures, and that one cannot step into the same river twice. Beneath the flux is the Logos, the hidden harmony of opposites. Panta rhei is a later summary of his view.
Panta rhei
“All things flow”: the teaching attributed to Heraclitus that everything is in constant change.
Also: everything flows