Everything changes and nothing stands still.

Πάντα ῥεῖ | Everything flows. | This statement occurs in Simplicius' Commentary on Aristotle's Physics, 1313.11; while some sources attribute to Simplicius the coining of the specific phrase "πάντα ῥεῖ (panta rhei)", meaning "everything flows/is in a state of flux", to characterize the concept in the philosophy of Heraclitus, the essential phrasing "everything changes" and variations on it, in contexts where Heraclitus's thought is being alluded to, was current in both Plato and Aristotle's writings.

and variant translations: Everything flows and nothing stays. Everything flows and nothing abides. Everything gives way and nothing stays fixed. Everything flows; nothing remains. All is flux, nothing is stationary. All is flux, nothing stays still. All flows, nothing stays.