The Tyranny of Clichés:
How Liberals Cheat 
in the War of Ideas
By Jonah Goldberg
Sentinel, 320 pages

Violence never solved anything. Diversity is strength. We're only as free as the least free among us. One man's terrorist is another man's freedom fighter. Dissent is the highest form of patriotism. It's a slippery slope. I disapprove of what you say, but I will defend to the death your right to say it.

Deploy one of these hoary, haughty pronouncements, and you may conclude you have made a watertight case and whatever discussion you are having can now come to a close, your interlocutor silenced by the unanswerable truth of your assertion.