What convinces is conviction. Believe in the argument you're advancing. If you don't you're as good as dead. The other person will sense that something isn't there, and no chain of reasoning, no matter how logical or elegant or brilliant, will win your case for you.
Lyndon B. JohnsonI won't have you electioneering on my doorstep. Every time you get in trouble in Parliament you run over here with your shirttail hanging out.
Lyndon B. Johnson