The mechanism of responsibility
In this book, we see an attempt to categorize rules which if followed will lead to mental clarity, balance, and health. This description of mental health has moral responsibility at its center. The mechanism of personal responsibility is as follows: each personal choice has consequences, and by ignoring those consequences, or by pretending the consequences are different than they are, a person makes their mental health fractured by lying to themselves. This means that mental health begins for Epictetus with accepting the consequences of one's actions.
Discipline and athleticism
The Stoic life depends on a practice of discipline. Just as the athlete prepares for competition by training and practice, so also Epictetus says that a Stoic should train and practice. By learning which impulses to deny and by training one's self to do what is ethical and advantageous, he says that a person's mind can become disciplined. He uses the body's athletic ability as a symbol for this discipline, saying that mental discipline is very similar to physical skill.
Relationships and boundaries
There is a motif between relationships and boundaries. The Stoic should understand the boundaries that lie between a person's will power and various types of external reality. This is done in an attempt to fix one's desire for control. By understanding the ethical use of power, one respects boundaries which are not theirs to cross. A man should not try to manipulate other people, God, or one's self. The Stoic understands what is properly his to control and what isn't, and they masterfully manage only their own responsibilities.
Ethics and justice
Epictetus returns to the common philosophical question of justice and personal ethics. This motif might remind readers of Plato's Republic, and for good reason. Ethical life is done in an attempt to bring justice to one's soul. The concept of justice is shown to be a kind of functional order that skillfully accomplishes the right goals by correct action. This often involves self-control and empathy, because in order to properly justify one's soul, one has to align their self to their community in an empathetic, mutually beneficial manner.
The caste system
Epictetus argues that people are essentially playing roles within a caste system that he explains. He says that there are people whose lives are obviously centered around the spiritual reality, and there are those who are so embedded in their physical reality that the questions of spirit seem bizarre and irrelevant to them. This motif might remind readers of the Hindu concept of Brahma and the Buddhist interpretation of it. This is one of the many similarities between Stoicism and Buddhism.
