Heraclitus
c. 535 – c. 475 BCE · Ephesus, Ionia
The philosopher of change, who held that everything flows and that the world is held together by the tension of opposites.
Key ideas
Heraclitus taught that the world is in constant flux. Things that seem stable, a river or a body or a city, are really patterns held steady by continuous change, the way a flame keeps its shape while its fuel is replaced. The famous river fragment makes the point: the water you step into is never the same water twice. This makes him the ancient ancestor of every puzzle about identity over time, including the Ship of Theseus.
He also held that opposites belong together. The road up and the road down are one and the same; health is pleasant only because there is sickness. Behind the strife he saw an ordering principle he called the logos, a rational structure most people fail to notice even though it is right in front of them.
His style was compressed and riddling, and later Greeks nicknamed him 'the Obscure'. Only around a hundred short fragments survive, quoted by other writers, which is why every interpretation of him is partly a reconstruction.
“You cannot step twice into the same rivers; for fresh waters are ever flowing in upon you.”
Heraclitus, Fragment 41, trans. John Burnet (1892)
Life, briefly
Heraclitus came from an aristocratic family in Ephesus, a Greek city on the coast of what is now Turkey. Ancient biographies say he gave up a hereditary office to his brother and lived apart, scornful of both the public and earlier thinkers. Most of the colourful stories about him, including the account of his death, are later inventions and should be read as legend.
Major works
- A single book, usually called On Nature, surviving only in fragments
Appears in
Further reading
- EncyclopediaStanford Encyclopedia of Philosophy: Heraclitus
- WikipediaHeraclitus