No number of sightings of white swans can prove the theory that all swans are white. The sighting of just one black one may disprove it.
Karl PopperA rationalist, as I use the word, is a man who attempts to reach decisions by argument and perhaps, in certain cases, by compromise, rather than by violence. He is a man who would rather be unsuccessful in convincing another man by argument than successful in crushing him by force, by intimidation and threats, or even by persuasive propaganda.
Karl Popper