Violence is the last refuge of the incompetent. It is the only resort by which incompetent men can thrive. The bully, the brute, the dictator.
Isaac Asimov, Foundation, Astounding Science-Fiction, May 1942, (This appears three times in "Bridle and Saddle" which is titled "The Mayors" in the 1951 novelization). It plays on the famous quote by Samuel Johnson (1775): "Patriotism is the last refuge of a scoundrel."