- Lived:
- c. 412–323 BCE · born in Sinope, a Greek port on the Black Sea; lived in Athens and Corinth
- Tradition:
- Classical Greek; Cynicism — philosophy as a way of life, performed in public
- The Big Idea:
- Almost everything you think you need — money, status, comfort, approval, even shame — is a social invention, and a human being who trains themselves to need almost nothing is freer than a king.
- In their words:
- "I am a citizen of the world."
- If you remember one thing:
- He wrote almost nothing and built no system; instead he lived his philosophy in the street, in a ceramic jar, with a lamp lit at noon — and the performance was the argument.