If you would have your children and your wife and your friends to live forever, you are silly; for you would have the things which are not in your power to be in your power, and the things which belong to others to be yours. So if you would have your slave to be free from faults, you are a fool; for you would have badness not to be badness, but something else. But if you wish not to fail in your desires, you are able to do that. Practice, then, this which you are able to do. He is the master of every man who has the power over the things, which another person wishes or does not wish, the power to confer them on him or to take them away. Whoever then wishes to be free, let him neither wish for anything nor avoid anything which depends on others: if he does not observe this rule, he must be a slave.