Antisthenes

Antisthenes was a pupil of the sophist Gorgias of Leontini and the philosopher Socrates. He taught at the gymnasium of Kynosarges in Athens and was the teacher of Diogenes of Sinope.

He mainly developed asceticism and self-control. He also distinguished between external goods (sensual pleasure) and internal goods (truth, knowledge of the soul). For these he rejected their balance and, on the contrary, argued that inner goods can only grow if outer goods diminish. He also rejected the Platonic doctrine of ideas.

His writings, however, have not survived.