Do we fear things that aren't actually harmful? No. Do we fear things that are harmful but still under our control so we can prevent them? Of course not. If external things are neither good nor bad, and everything that depends on our will is within our power — and no one can take these things from us or give them to us unless we let them — then what's left to worry about? But we worry about our weak body, our little bit of money, what Caesar thinks of us. We don't worry about what's inside us.
Is any man then afraid about things which are not evils? No. Is he afraid about things which are evils, but still so far within his power that they may not happen? Certainly he is not. If then the things which are independent of the will are neither good nor bad, and all things which do depend on the will are within our power, and no man can either take them from us or give them to us, if we do not choose, where is room left for anxiety? But we are anxious about our poor body, our little property, about the will of Cæsar; but not anxious about things internal.