Epictetus, like Socrates, expressed his thoughts out loud, and his “Discourses” were recorded by his student, the historian Arrian. His philosophy emphasizes the importance of kindness and purity of the soul, and it urges respect for all people. The goal of philosophy is to learn to distinguish what is within our power and what isn’t. The outside world and circumstances cannot be controlled by us, and therefore it is not things that make us happy or unhappy, but our perceptions of them. Our thoughts and desires are subject to our influence, and therefore our happiness depends on us ourselves.