5 ideas
Everything that happens falls into one of two bins. Up to us are judgment, impulse, desire and aversion, our own acts of choice. Not up to us are body, property, reputation, office and other people's actions. Placing desire or aversion on anything in the second bin guarantees frustration and servility, because whoever controls that thing now controls you; freedom comes from moving all wanting and fearing into the first bin.
People are disturbed not by things but by their opinions about things: death is not terrible, but the judgment that death is terrible is. Every impression should be interrogated before assent ('You are an appearance, not the thing you appear to be'), so the gap between event and reaction becomes the place where emotional suffering is prevented or produced.
Outcomes and circumstances are like the ball in a game: players do not value the ball itself, only skill in catching and throwing it. Uncertain externals are raw material, and what counts is the quality of your handling of them. You can therefore act with full effort and care toward a result while holding the result itself as indifferent. This is how to decide well when you cannot know or control the outcome.
Vespasian told Helvidius Priscus not to attend the Senate, and Helvidius replied that Vespasian could remove him as senator, but while he remained one he must go and would say what seemed right, even under threat of death. Epictetus uses the exchange to show that an emperor could take away Helvidius's office and his life but not his choice to act and speak as his conscience required.
A thief stole the iron lamp from beside Epictetus's household shrine, and Epictetus remarked that tomorrow he would buy an earthenware one. His point was that a person loses only what he has. The thief paid for the lamp by becoming a thief, trading his character for a lamp, while Epictetus lost only a cheap object. The episode demonstrates the discipline of refusing to treat a loss of externals as injury, and of reframing possessions as things lent and returned.