The appeal of science fiction has always been its iconoclasm . . . But in order to be an iconoclast, an author must be more than merely aware of the idol he wishes to destroy. He must be intimate with it and understand it in all its aspects. This means that he must have devoted serious thought to it, and have beliefs of his own which will stand up in the place of the broken idol. In other words, any child can complain, but it takes an adult to clash with accepted beliefs . . . an adult with ideas.