Zeno of Citium (336-264): philosopher from Cyprus, founder of the philosophiocal school that is known as Stoicism or the Stoa.
After the conquests of Alexander the Great, the world was larger than ever, and the city-state had ceased to be an important political unit. Like Diogenes of Sinope and Epicurus, Zeno of Citium ignored traditional values like prestige and honor, and focused on man's inner peace.
In his view, this was reached when a person accepted life as it was, knowing that the world was rationally organized by the logos. A man's mind should control his emotions and body, so that one could live according to the rational principles of the world. This philosophy, called Stoicism, became very influential under Roman officials.
It has often been said that Zeno's ideas combine Greek philosophy with Semitic mysticism, but except for his descent from a Phoenician town on Cyprus and an interest in (Babylonian) astronomy, there is not much proof for this idea. This second aspect -the astronomy- however, needs to be taken very seriously.
Zeno was succeeded as head of the Stoic school by Chrysippus.