You are quite astray if you desire your wife and children and friends to live for ever, for then you are desiring things that are not of yourself to be of yourself, and to control that which is not in your power. So also if you desire that your servant never should display any shortcomings, you are a fool; for that is as much as to desire that imperfection should not be imperfection, but something else. But If you wish never to fall short of your desires, this indeed is possible to you; this therefore practice, namely, the practicable.
You own a master when another has power over the things that are pleasing or displeasing to you, to give them or to take them away. Whosoever then would be free, let him neither desire nor shun any of the things that depend not upon himself; otherwise he must needs be enslaved.