There was once a man from Linnorm. As Linnorm is so far away, I can say whatever I want about it, and my readers will be none the wiser; so I say that in Linnorm, there were no laws at all, not even a law against murder. In this land was born a man who loved murder greatly, who is the subject of this (assuredly real) story.
Every morning, the man would rise and murder one of his neighbors; every day, the man would accept money for services as an assassin; every night, the man would slay five innocent children before he slept.
But one day, as the man went to murder a child, the child called out to him. "Don't you know that murder is Evil?"
The man was greatly surprised, for in all his long years as a murderer, it had never once occurred to him that murder might be Evil. "What do you mean?" said the man.
"I mean," said the child, "that it hurts people, and you shouldn't do it."
In shock and horror, the man realized that murder was Evil. "I cannot believe that I have done such an Evil thing!" said the man. "Nevermore will I murder anyone!"
Then the man went home and did not do any more murder. The end!