Diogenes of Sinope was a Greek philosopher and one of the founders of Cynic philosophy. Also known as Diogenes the Cynic, he was born in Sinope, an Ionian colony on the Black Sea, in 412 or 404 BC and died at Corinth in 323 BC.
Diogenes of Sinope was a controversial figure. His father minted coins for a living, and when Diogenes took to "defacement of the currency," he was banished from Sinope. After being exiled, he moved to Athens to debunk cultural conventions. Diogenes modelled himself on the example of Hercules. He believed that virtue was better revealed in action than in theory. He used his simple lifestyle and behaviour to criticise the social values and institutions of what he saw as a corrupt society. He declared himself a cosmopolitan. There are many tales about him dogging Antisthenes' footsteps and becoming his faithful hound. Diogenes made a virtue of poverty. He begged for a living and slept in a large ceramic jar in the marketplace. He became notorious for his philosophical stunts such as carrying a lamp in the daytime, claiming to be looking for an honest man. He embarrassed Plato, disputed his interpretation of Socrates and sabotaged his lectures. Diogenes was also responsible for publicly mocking Alexander the Great.