Cynicism (Ancient Greek: κυνισμός) is a school of thought in ancient Greek philosophy, originating in the Classical period and extending into the Hellenistic and Roman Imperial periods. According to Cynicism, people are reasoning animals, and the purpose of life and the way to gain happiness is to achieve virtue, in agreement with nature, following one's natural sense of reason by living simply and shamelessly free from social constraints. The Cynics (Ancient Greek: Κυνικοί, Latin: Cynici) rejected all conventional desires for wealth, power, glory, social recognition, conformity, and worldly possessions and even flouted such conventions openly and derisively in public.
The first philosopher to outline these themes was Antisthenes, who had been a pupil of Socrates in the late 400s BC. He was followed by Diogenes, who lived in a ceramic jar on the streets of Athens. Diogenes took Cynicism to its logical extremes with his famous public demonstrations of non-conformity, coming to be seen as the archetypal Cynic philosopher. He was followed by Crates of Thebes, who gave away a large fortune so he could live a life of Cynic poverty in Athens.