If you can’t be sure of being right, why should you tell other people they are wrong? You can tell people they are wrong by a look or an intonation or a gesture just as eloquently as you can in words – and if you tell them they are wrong, do you make them want to agree with you? Never! For you have struck a direct blow at their intelligence, judgement, pride and self-respect. That will make them want to strike back. But it will never make them want to change their minds. You will not alter their opinions, for you have hurt their feelings.
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. If a person makes a statement that you think is wrong – yes, even if you know is wrong – isn’t it better to begin by saying: “Well, now, look. I thought otherwise, but I may be wrong. I frequently am. And if I am wrong, I want to be put right. Let’s examine the facts.”
You will never get into trouble by admitting that you may be wrong. That will stop all argument and inspire your opponent to be just as fair and open and broadminded as you are. It will make him want to admit that he, too, may be wrong. Don’t argue with your customer or your spouse or your adversary. Don’t tell them they are wrong, don’t get them stirred up. Use a little diplomacy.
*Compilation taken from “How to Win Friends and Influence People,” by Dale Carnegie