"Never combat any man's opinion; for though you reached the age of Methuselah*, you would never have done setting him right upon all the absurd things that he believes." - German philosopher Arthur Schopenhauer (1788-1860)
* In the Hebrew bible, Methuselah is purportedly the oldest person to have ever lived. He died at the age of 969.
I have seen some strange things in my time.
I have seen a bird chase a cat. I have seen a fireball streak across the night sky. I have seen a river boil.
But there is one thing that I have never seen.
I have never - not even once - seen anyone stop himself in the middle of an argument and say: "You know what? You've convinced me. I had it all wrong."
I have seen atheists argue with believers, Republicans argue with Democrats, psychics argue with sceptics and so on and so on, ad nauseum.
But I do not recall ever having seen anyone actually change his mind as a result.
The futility of argument
It is really quite remarkable. Arguments are, on the face of it, free and frank exchanges of ideas; rational investigations into the reasons for accepting or rejecting certain viewpoints.
So you would expect that, at least some of the time, they would bring about changes of opinion.
But they never do.
On the contrary, nine out of 10 times, arguments leave the opposing sides more deeply entrenched in their positions than they were to begin with.
It took me a long time to realise that. For most of my life, I believed that if someone had formed an opinion based on faulty reasoning and you were able to point out his mistake, then you could get him to rethink his position and perhaps change his mind.
But long experience has taught me that this is not so.
People cling tenaciously to their opinions. And the most ill-informed and ill-judged opinions are clung onto every bit as tightly as the rest.
In his classic self-help book, How To Win Friends And Influence People, American writer and public speaker Dale Carnegie recounted how, as a young man, he loved to argue.
So much so that he took courses in logic and argumentation at college and later went on to teach those subjects to others.
After years of engaging in arguments, studying arguments, listening to arguments and criticising arguments, he concluded: "There is only one way under high heaven to get the best of an argument - and that is to avoid it."
When you try to argue someone out of a cherished notion, you may succeed in annoying or upsetting him, but you will not succeed in convincing him.
Not even if you are right. People are surprisingly impervious to reason.
Carnegie put it like this: "When dealing with people, let us remember that we are not dealing with creatures of logic.
"We are dealing with creatures of emotion, creatures bristling with prejudices and motivated by pride and vanity."
This includes everyone. However logical we believe ourselves to be, we are all "creatures of emotion".
All of us, too, are "bristling with prejudices and motivated by pride and vanity".
When it comes to our most cherished ideas, we, too, are surprisingly impervious to reason.
This is not to say that people never change their minds about important matters.
Clearly, they sometimes do.
But such changes take place slowly and gradually and cannot be forced.
American writer Marilyn Ferguson once wrote: "No one can persuade another to change.
"Each of us guards a gate of change that can only be opened from the inside.
"We cannot open the gate of another, either by argument or emotional appeal."
You cannot browbeat people into changing their opinions.
The most you can do is to drop seeds into their minds and hope that eventually they might bear fruit.
Gary Hayden is a philosophy and science writer.
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