There are things which are within our power, and there are things which are beyond our power. Within our power are opinion, aim, desire, aversion, and, in one word, whatever affairs are our own. Beyond our power are body, property, reputation, office, and, in one word, whatever are not properly our own affairs.

One of the most basic tenets of Epictetus's teachings is that some things are in a person's power and other things are not. A person cannot control everything around them or everything that affects them. Choosing to focus on what you can control is what will make you happier and more content. He says that to focus on what can't be controlled will make a man angry and cause him to rail against God and other men. If, however, a person focuses on what they can control, they will be a better man. One example of this he gives is accepting it when people speak ill of you and seeing that their view is their own, not the only truth.

Never say of anything, "I have lost it"; but, "I have returned it." Is your child dead? It is returned. Is your wife dead? She is returned. Is your estate taken away? Well, and is not that likewise returned? "But he who took it away is a bad man." What difference is it to you who the giver assigns to take it back? While he gives it to you to possess, take care of it; but don't view it as your own, just as travelers view a hotel.

Another thing that Epictetus focuses on is not clinging to things. Anything can be taken from you. If you love a particular ceramic cup, for example, it can break. If, however, you love ceramic cups in general, you won't lose what you love. There are always more ceramic cups. He extends this even to beloved family members. Everything that a person has is only on loan in life; if you're prepared to lose it at any time and see it as a temporary thing, you won't be shocked and unhappy when it's gone.

The first and most necessary topic in philosophy is the practical application of principles, as, We ought not to lie; the second is that of demonstrations as, Why it is that we ought not to lie; the third, that which gives strength and logical connection to the other two, as, Why this is a demonstration. For what is demonstration? What is a consequence? What a contradiction? What truth? What falsehood? The third point is then necessary on account of the second; and the second on account of the first. But the most necessary, and that whereon we ought to rest, is the first. But we do just the contrary. For we spend all our time on the third point and employ all our diligence about that, and entirely neglect the first. Therefore, at the same time that we lie, we are very ready to show how it is demonstrated that lying is wrong.

Epictetus believes that a man should adopt his own personal rules as if they were laws to live by and never break them. This practical application of theoretical philosophical concepts is very important to him and is something that he views as a weakness in philosophy. He sees the discipline as focused on abstract rules, debate, and discussion. He believes that philosophers should instead focus on actually applying those principles to their lives. That's where he thinks they fall short. At the end of his text, he suggests that they focus more on the application and less on the discussion of theoretical concepts.