Antisthenes, a student of Socrates, taught at a gymnasium outside Athens called Cynosarges, “the place of the white dog”. That is one story for the name. The other is that Athenians called Diogenes “the dog”, kyon, for eating, sleeping and relieving himself in public, and that he took the insult as a title. Both stories are probably true.
Diogenes came from Sinope on the Black Sea, exiled after a scandal over the city’s coinage. In Athens he made his home in a large storage jar, carried a lamp in daylight looking for an honest man, and when Alexander the Great offered him anything he wanted, asked him to step out of the sun. Crates of Thebes gave away a fortune to follow him. Hipparchia of Maroneia gave up a good marriage to marry Crates instead, and became the first woman in the school. Nearly everything we know is anecdote. The Cynics would not have minded; the anecdote was the lesson.
Virtue is enough. Happiness needs no money, no status and no permission. Anything else you think you need is a habit.
Train for it. Askesis meant hardship on purpose: cold, hunger, walking barefoot in snow. A body that wants nothing cannot be bribed.
Say it to their face. Parrhesia, frank speech, was the Cynic’s one luxury, and it was spent on kings.
Nature over convention. Anaideia, shamelessness: what is natural is not shameful, and what is merely customary has no claim on you.
Deface the currency. The oracle told Diogenes to do it, and he took it to mean every coin of accepted value: test it, and if it is counterfeit, say so.
Hipparchia is usually a footnote to Crates. She should not be. When a dinner guest mocked her for leaving the loom for philosophy, she asked whether he thought she had done wrong to spend on her education the time she would otherwise have spent weaving. He had no answer, and the story survived because nobody else did either.
The school was Anatolian and Syrian more than Athenian. Diogenes came from Sinope on the Black Sea, Menippus from Gadara, and Lucian, who wrote the best surviving Cynic portraits, from Samosata on the Euphrates.
Stoicism is the Cynics’ respectable child: Zeno learned from Crates, kept the ethics and dropped the jar. The Epicurean Garden shared the simple life but preferred it private. Diogenes heckled Plato in person, famously plucking a chicken to mock the definition of man as a featherless biped. And the Contrarian temperament described elsewhere on this site is Cynicism with its shoes on.
The English word “cynical” now means the opposite of what Diogenes meant. He assumed people could be better and said so to their faces; the modern cynic assumes they cannot and says nothing. Minimalism, anti-consumerism and the protest sign all borrow the pose. Diogenes remains the most quoted philosopher who left no writing at all.