The best way to get someone to accept an idea in the long-term, is to show the reasonableness of the idea.
Another way is to show the unreasonableness of all other ideas.
“Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.”
— Arthur Conan Doyle
The philosophy of reasonableness precludes arrogance.
Don’t trust those that won’t admit when they are wrong.