ABSTRACT
A biologist, a physicist, and a mathematician go on holidays in Scotland for the first time. While they are still in the train to Edinburgh, they see a black sheep. The biologist says: “Incredible! Sheeps are black in Scotland!” Annoyed, the physicist replies: “All that can be said is that there is at least a black sheep in Scotland”. The most influential thinker on this matter may be David Hume, an 18th century Scottish philosopher. Other philosophers of his time thought that they had proved necessary truths. For instance, Descartes seemed to have proved the existence of God, by pondering the essence of perfection. It is more perfect to exist than not to exist, he said. The heroes of the formalization of the theory of statistical errors are named Karl Pearson, Egon Pearson (his son), Jerzy Neyman, and, most importantly, Ronald Fisher.
