b. -300
The Stoics were a school of ancient Greek and Roman philosophy founded by Zeno of Citium in Athens around 300 BCE, named for the Stoa Poikile (Painted Porch) where they gathered. They developed a unified philosophical system spanning logic, physics, and ethics, with the central ethical doctrine that virtue is the only intrinsic good and that one must live in accordance with reason and nature (kata phusin). The tradition produced major figures across six centuries, including Chrysippus, Seneca, Epictetus, and Marcus Aurelius.
Established virtue as the sole intrinsic good, founding a rigorous virtue ethics independent of external outcomes
Developed natural law theory as the universal rational standard grounding moral obligation
Advanced cosmopolitanism: the doctrine that all rational beings share a common moral community
Built a systematic propositional logic through Chrysippus, anticipating modern formal logic
Distinguished 'preferred indifferents' from genuine goods, enabling nuanced practical ethics