Of all existing things, some are in our power, and others are not in our power. So begins the Enchiridion or Manual on the Art of Living of Epictetus, a collection of precepts that together provide a powerful philosophy for daily life. With practical grace and wisdom, the Manual addresses living with integrity, self-management, and personal freedom. The Manual is considered to be the pinnacle of Stoic philosophy, a school of Greek thought originating in the early third century BC, that holds that destructive emotions are the result of errors in judgement and taught an active relationship between individual will and cosmic determinism.