[+/-] Certitude leads to violence

The lesson [Oliver Wendell] Holmes took from the war can be put in a sentence. It is that certitude leads to violence. This is a proposition that has an easy application and a difficult one. The easy application is to ideologues, dogmatists, and bullies--people who think that their rightness justifies them in imposing on anyone who does not happen to subscribe to their particular ideology, dogma, or notion of turf. If the conviction of rightness is powerful enough, resistance to it will be met, sooner or later, by force. There are people like this in every sphere of life, and it is natural to feel that the world would be a better places without them.

-- Louis Menand's The Metaphysical Club: A Story of Ideas in America (Winner of the 2002 Pulitzer Prize for History)

Sounds like Holmes was thinking of modern-day reTHUGlican fundies.