The Basic Laws of Human Stupidity
by Carlo Maria Cipolla.

 

Always and inevitably everyone underestimates the number of stupid individuals in circulation.

The probability that a certain person will be stupid is independent of any other characteristic of that person.

A stupid person is a person who causes losses to another person or to a group of persons while himself deriving no gain and even possibly incurring losses.

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 always turns to be costly mustake.