A well known philosopher of ancient Greece, Antisthenes was born in Athens, son of an Athenian and a woman from Thrace. Contemporary to Plato, although older, he was a student of Gorgias and a friend and faithful admirer of Socrates. After the death of his great tutor, he founded an academy near Cynosarges Gymnasium. It is from that name that his students were named Cynicals and their movement Cynism. A famous pupil was Diogenis of Sinope.
Socrates admired him for his abstinent and ascetic way of life. In his conversations he tried to falsify the definition Socrates gave to general concepts. He fought against the Platonic theory of ideas, and believed that the only real concepts are the ones we feel using our senses (aesthetic teaching, aesthisi= the greek word for senses).
General concepts according to Antisthenes do not exist (“I see a horse, but I cannot see the “horseness”). By this he concludes that we cannot give to a subject a different meaning other than what makes its identity to be such (eg, gold is gold rather than gold is yellow, mortal is mortal rather than a man is mortal)
That is why Antisthenes rejected the definition of the primary characteristics. These teachings were willingly adopted by the Cynicals, leading them to the effort of making themselves totally independent of human needs, reducing their personal needs to the least, exercising to endure every discomfort and considering pleasure as the ultimate evil.