“Happiness and freedom begin with a clear understanding of one principle: Some things are in our control, and some things are not. It is only after you have faced up to this fundamental rule and learned to distinguish between what you can and can’t control that inner tranquility and outer effectiveness become possible.
“Within our control are our opinions, aspirations, desires, and the things that repel us. These are quite rightly our concern, because they are directly subject to our influence. We always have a choice about the contents and character of our inner lives.
“Outside our control, however, are such things as what kind of body we have, whether we’re born into wealth or strike it rich, how we’re regarded by others, and our status in society. We must remember that these things are externals and are therefore not our concern. Trying to control or change what we can’t only results in torment.
“Remember: The things within our control are naturally at our disposal, free from restraint or any hindrance; but those things outside our control are weak, dependent, or determined by the whim and actions of others. Remember, too, that if you think that you have free rein over things that are naturally beyond your control, or if you attempt to adopt the affairs of others as your own, your pursuits will be thwarted and you will become a frustrated, anxious, and fault-finding person.”
– Epictetus, Sharon Lebell, The Art of Living
Mind / Purpose / Truth 