And those characters [in a fairy tale] dwell in a moral world, whose laws are as clear as the law of gravity. That too is a great advantage of the folk tale. It is not a failure of imagination to see the sky blue. It is a failure rather to be weary of its being blue- and not to notice how blue it is. And appreciation of the subtler colors of the sky will come later. In the folk tale, good is good and evil is evil, and the former will triumph and later will fail. This is not the result of the imaginative quest. It is rather its principle and foundation. It is what will enable the child later on to understand Macbeth, or Don Quixote, or David Copperfield.
