Never begin by announcing “I am going to prove so-and-so to you.” That’s bad. That’s tantamount to saying: “I’m smarter than you are. I’m going to tell you a thing or two and make you change your mind.” That is a challenge. It arouses opposition and makes the listener want to battle with you before you even start. It is difficult, under even the most benign conditions, to change people’s minds. So why make it harder? Why handicap yourself? If you are going to prove anything, don’t let anybody know it. Do it so subtly, so adroitly, that no one will feel that you are doing it.
