Diogenes of Sinope

Diogenes came from Sinope on the Black Sea, exiled for 'defacing the currency', a phrase he later adopted as his philosophical programme: to restamp the values in circulation. In Athens he followed Antisthenes, a pupil of Socrates, and pushed his teacher's austerity to the limit, living in a large storage jar beside a temple with only a cloak, a staff and a begging bag. Seeing a child drink from cupped hands, he threw away his cup.

The anecdotes are his philosophy. He walked the market in daylight with a lamp, saying he was looking for a human being. When Plato defined man as a featherless biped, he plucked a chicken and tossed it into the Academy: here is Plato's man. Alexander the Great came to see him and asked what he could do for him; Diogenes asked him to stand out of his sunlight. He ate and masturbated in public, wishing that rubbing the belly could relieve hunger as easily.

Behind the performances lay a clear claim: convention is artificial and nature is the measure; wealth, fame and respectability are illusions, and only those who need none of them are free. He called himself a citizen of the world, the first recorded use of the word cosmopolitan. Cynicism had no doctrine, only a way of life, and it directly shaped Zeno, the founder of Stoicism.