Chapter 8: The Fourth Basic Law (The Basic Laws Of Human Stupidity)

The helpless, intelligent, and the bandits all underestimate the danger posed by stupid people.

Law 4: Non-stupid people always underestimate the damaging power of stupid individuals. In particular non-stupid people constantly forget that at all times and places and under any circumstances to deal and/or associate with stupid people infallibly turns out to be a costly mistake

Carlo Cipolla, The Basic Laws of Human Stupidity

"A gilded No is more satisfactory than a dry yes" - Gracian