In nine cases out of ten the speaker or writer who, seeking to influence public opinion, descends from calm argument to unfair blows hurts himself more than his opponent.
The Chinese have a story on this—a story based on three or four thousand years of civilization: Two Chinese coolies were arguing heatedly in the midst of a crowd. A stranger expressed surprise that no blows were being struck. His Chinese friend replied: "The man who strikes first admits that his ideas have given out."

Fireside Chat in the night before signing the Fair Labor Standards (June 24, 1938)