- Zeno of Citium (/ˈziːnoʊ/; Koinē Greek: Ζήνων ὁ Κιτιεύς, Zēnōn ho Kitieus; c. 334 – c. 262 BC) was a Hellenistic philosopher from Citium (Κίτιον, Kition), Cyprus. He was the founder of the Stoic school of philosophy, which he taught in Athens from about 300 BC. Based on the moral ideas of the Cynics, Stoicism laid great emphasis on goodness and peace of mind gained from living a life of virtue in accordance with nature. It proved very popular, and flourished as one of the major schools of philosophy from the Hellenistic period through to the Roman era, and enjoyed revivals in the Renaissance as Neostoicism and in the current era as Modern Stoicism.