There is nothing permanent except change.

Heraclitus of Ephesus (fl. c. 500 BCE) is known through fragments of a lost work (often titled On Nature) preserved by later authors. His philosophy emphasized flux and becoming: reality is not a fixed set of stable substances but an ongoing process governed by logos (an underlying rational order). The popular English sentence “There is nothing permanent except change” is a later paraphrase that condenses this Heraclitean outlook, closely associated with his river imagery (we cannot step into the same river twice) and his insistence that apparent stability is produced by continuous transformation and tension between opposites.

The line expresses the core Heraclitean claim that change is not an occasional disturbance of an otherwise stable world; it is the world’s basic condition. What seems permanent—objects, identities, institutions—persists only through ongoing alteration, like a river that remains “the same” only because new waters continually flow. The paradox (“permanence” consists in “change”) challenges common sense and invites a shift from thinking in static categories to thinking in processes and relations. In Heraclitus, this flux is not mere chaos: it is patterned by logos, so change is intelligible and structured even when it unsettles human expectations.

“The only constant is change.”
“Nothing endures but change.”
“Everything flows” (often given as the Latin tag “panta rhei,” used to summarize Heraclitus).