Everything is disputable. I am willing to entertain arguments in support of any proposition whatsoever.  
If you want to defend theft, mayhem, adultery, or murder, state your case, bring on your reasons; for in endeavoring to prove an indefensible thing you discover for yourself how foolish is your thesis.
 
But it is essential to any controversy, if it is to be of any use, first, that the issue be clearly understood by both sides.
 
Most contentions amount merely to a difference of definition. Agree, therefore, exactly upon what it is you are discussing. If possible, set down your statements in writing.
 
127
Most argument is a wandering from the subject, a confusion of the question, an increasing divergence from the point. Stick to the matter in hand.
 
When your adversary brings in subjects not relevant, do not attempt to answer them. Ignore them, lest you both go astray and drift into empty vituperation.
 
For instance, President Wilson, in the “Lusitania” incident, called Germany’s attention to the fact that her submarines had destroyed a merchant ship upon the high seas, the whole point being that this had been done without challenge or search and without giving non-combatant citizens of a neutral country a chance for their lives. Germany’s reply discussed points that had no bearing upon this issue, such as various acts of England. Mr. Wilson, in his reply, wisely refused to discuss these irrelevant 128 things, an example of intelligent controversy.
 
Keep cool. The worse your case, the louder your voice.
 
Be courteous. Avoid epithets. Do not use language calculated to anger or offend your opponent. Such terms weaken the strength of your position.
 
A controversy is a conflict of reasons, not of passions. The more heat the less sense.
 
Keep down your ego. Do not boast. Do not emphasize what you think, what you believe, and what you............