The philosophy asserts that virtue (meaning, chiefly, the four cardinal virtues of self-control, courage, justice, and wisdom) is happiness, and it is our perceptions of things—rather than the things themselves—that cause most of our trouble. Stoicism teaches that we can’t control or rely on anything outside what Epictetus called our “reasoned choice”—our ability to use our reason to choose how we categorize, respond, and reorient ourselves to external events.
