Overview
Heraclitus of Ephesus (fl. c. 500 BCE) was a Pre-Socratic who wrote a famously obscure book of aphorisms on logos, flux, and the unity of opposites. Ancient nicknames called him the obscure and the weeping philosopher. Only fragments survive via later quotation. Handbook floruit is around 500 BCE. He rivaled Parmenides as a pole of early Greek metaphysics.
Main ideas
All things flow; you cannot step into the same river twice—identity persists through change. Conflict is justice; opposites cohere in hidden harmony. Logos is common, yet many live as if they had private understanding. Fire symbolizes ordered transformation of the cosmos. Character is fate for a human; insolence should be quenched more than a blaze. Sleepers miss the shared world the waking logos discloses.
Major works
- On Nature (fragments)
- River fragments
- Logos fragments
- Political/ethical fragments
Legacy
Heraclitus inspired Stoics, Hegel’s dialectic imagery, and process philosophies. Poets prize his density; analysts reconstruct argument from shards. He remains flux’s classical spokesman.