"Zeno of Citium, Cyprus (334-262 BC) or Zenon Zenone ", 300 unknown Roman artisan - copy of a Greek original Capitoline Museums, Rome, Italy

Zeno of Citium (not to be confused with other philosophers also so called) belonged to a wealthy merchant family; he abandoned trade in late adulthood to become a student of philosophy with Crates, the most famous Cynic living at the time in Greece. Zeno established the school of Stoicism (his teaching was done at a Stoa or porch). His philosophy can be summarized by "tranquility can best be reached through indifference to pleasure and pain ..." and by "reason permeates nature and all things ... virtue is to live according to nature.". Zeno stressed "always to do what is appropriate or "kathekon" (as in catechism) ... when facing old age he decided to strangle himself. Zeno's impact on sciences and ethics is enduring and can be grasped from his aphorisms.