Photo by Hulton-Deutsch Collection/CORBIS/Corbis via Getty Images “Every writer should be his own censor.” Readers might be surprised to learn that this statement came from the mouth of the author Roald Dahl, in an interview given in 1989 less than a year before he died. “I don’t hold with all this ‘I’m a member of the Society of Authors’ stuff,” he went on. “They seem to think that unlike other people they have a God-given right to publish exactly what they want. All of us should exercise a degree of censorship. In my children’s books, there’s a wild degree of...