With everything which entertains you, is useful, or of which you are fond, remember to say to yourself, beginning with the very least things, “What is its nature?” If you are fond of a jug, say, “I am fond of a jug”; for when it is broken you will not be disturbed. If you kiss your own child or wife, say to yourself that you are kissing a human being; for when it dies you will not be disturbed.