Cuncta fluunt is the Latin rendering of
Heraclitus's famous doctrine of universal flux, expressed in Greek as panta rhei (everything flows). Ovid gives the most extended Latin poetic treatment of this doctrine in the Metamorphoses (XV), where the Pythagorean philosopher Pythagoras expounds on universal change. Students should note that the Heraclitean doctrine is subtler than mere change: Heraclitus also argued that
there is a logos (rational principle) governing the flux, so that
the universe is not merely chaotic but ordered change. This combination of flux and logos is important for understanding how poets use the theme of change: the elegy is not just about the fact of change but about the logos — the meaning — that can be found
within it. Related terms include
tempus fugit (
time flies), mutatio (change), the river as a symbol of time, and the Ovidian theme of metamorphosis.