Heraclitus of Ephesus
535–475 BC
Pre-Socratic·Graecia
Heraclitus wrote in fragments — deliberately obscure, demanding active interpretation. He believed the logos, a rational principle underlying all change, was the true nature of reality. His central insight: opposites are necessary to each other. Day requires night. Life requires death. The river is always the same river and never the same river.
Key Ideas
01
Panta rhei — everything flows, nothing stands still
02
The unity of opposites — tension as the source of all existence
03
Fire as the primary substance — always transforming
04
The logos — universal reason that most people cannot hear