To master anything, one must first master themselves–one’s emotions, one’s thoughts, one’s actions. Eisenhower famously said that freedom is really the opportunity to practice self-discipline. Cicero called the virtue of temperance the polish of life. Without boundaries and restraint, we risk not only failing to meet our full potential and jeopardizing what we have achieved, but we ensure misery and shame. In a world of temptation and excess, this ancient idea is more urgent than ever.