When any person harms you, or speaks badly of you, remember that he acts or speaks from a supposition of its being his duty. Now, it is not possible that he should follow what appears right to you, but what appears so to himself.
Then bring to your mind both points of time: that in which you will enjoy the pleasure, and that in which you will repent and reproach yourself after you have enjoyed it; and set before you, in opposition to these, how you will be glad and applaud yourself if you abstain.
take notice, you will behave like children who sometimes play like wrestlers, sometimes gladiators, sometimes blow a trumpet, and sometimes act a tragedy when they have seen and admired these shows. Thus you too will be at one time a wrestler, at another a gladiator, now a philosopher, then an orator; but with your whole soul, nothing at all.