Stoicism, founded in 3rd century BC Greece by Zeno of Citium, is a philosophy focusing on personal ethics, self-control, and fortitude to overcome negative emotions. It advocates for living virtuously, in alignment with logic and nature, and teaches that true happiness comes from accepting life’s moments as they are, without succumbing to pleasure or fear. Prominent Stoics like Seneca, Epictetus, and Marcus Aurelius emphasized achieving tranquility by practicing self-control, thus aligning with the universe’s rational order.