Diogenes of Sinope c. 412 BC – 323 BC

Diogenes of Sinope was an ancient Greek philosopher and one of the founders of the Cynic school. After his exile from Sinope on the Black Sea coast he settled in Athens, where he lived in deliberate poverty and used public spectacle to expose what he took to be the folly of conventional values. He is said to have lived in a large ceramic jar and to have walked through Athens in daylight with a lighted lamp claiming to look for an honest man. He left no writings of his own; his teachings and many famous anecdotes survive in the Lives of Eminent Philosophers by Diogenes Laertius. His radical asceticism and his concept of a cosmopolitan citizenship of the world were taken up and softened by the Stoics.

Diogenes of Sinope (c. 412–323 BC) was the founding philosopher of the Cynic tradition and one of the most distinctive moral exemplars of antiquity. Born in Sinope on the Black Sea coast, he was exiled — the surviving accounts cite his involvement in defacing the local coinage — and settled in Athens, where he attached himself to the Socratic philosopher Antisthenes.

Diogenes wrote nothing — at least, nothing that has survived — and is known almost entirely through anecdote in Diogenes Laertius and other later sources. The image is consistent across the sources: he lived in a wine jar, owned almost nothing, slept in temple porticos, performed bodily functions in public to demonstrate the artificiality of social conventions, and treated philosophy as the public performance of natural virtue against civilized pretense. The famous encounter with Alexander the Great — Alexander asks what Diogenes wants and Diogenes asks him to step out of the sun — captures the philosophical attitude.

Diogenes's Cynicism shaped the broader Hellenistic moral landscape. Crates of Thebes, Diogenes's most famous student, taught Zeno of Citium, and Stoicism preserved the Cynic ethical core within a more systematic philosophical framework. The Cynic tradition itself continued for centuries in the figures of Bion, Menippus, and the imperial Cynics. He died in Corinth, traditionally on the same day as Alexander, around 323 BC.