Frederick William I ruled Prussia in the early eighteenth century. Frederick walked the streets of Berlin unattended, and when anyone displeased him, he did not hesitate to use his walking stick to thrash them. Berliners tried to keep their distance. One time, as Frederick William was pounding down the street, a citizen spied him but too late, and his attempt to slide quietly into a doorway proved a failure.

"You," called out Frederick William, "where are you going?"

"Into the house, Your Majesty," said the citizen, trembling violentl…