Heraclitus

Heraclitus lived around 500 BC in Ephesus, then under Persian rule, and wrote a single work now lost except for scattered pieces. Even in antiquity his paradoxes and cryptic epigrams made him hard to parse; his temperament didn't help — contemporaries thought him arrogant, depressed, misanthropic, earning him the nickname "the weeping philosopher" in contrast to Democritus the laughing one. His philosophy turned on the unity of opposites and the primacy of change: the world constantly in flux, always becoming, never static being, with harmony found in strife itself. He believed fire was the fu…