Stoicism, founded in the early 3rd century BCE by Zeno of Citium, remains one of the most influential philosophies in Western history. It emerged in a period of great instability following the death of Alexander the Great, offering a psychological "inner citadel" against the chaos of the external world. While it began as a comprehensive system of logic, physics, and ethics in Greece, it eventually morphed into a practical manual for leadership and endurance in the Roman Empire. The Greek Foundation: Virtue as the Only Good

The early Greek Stoics—Zeno, Cleanthes, and Chrysippus—built a rigorous framework based on the idea that the universe is a rational, organized whole governed by Logos (divine reason). For the Greeks, the goal of life was eudaimonia (flourishing), achieved by living in accordance with nature.

A playwright and advisor to Emperor Nero, Seneca’s writings focus on the brevity of life and the management of emotions like anger and grief. His Letters from a Stoic are masterpieces of practical advice, showing how a person can maintain integrity even while living in the corrupting influence of high politics.

The Fortress of the Mind: Evolution and Legacy of Greek and Roman Stoicism