Let Them At Least Have Heard of Brave Knights
A far more serious attack on the fairy tale as children's literature comes from those who do not wish children to be frightened. I suffered too much from night-fears myself in childhood to undervalue this objection. I would not wish to heat the fires of that private hell for any child. On the other hand, none of my fears came from fairy tales. Giant insects were my specialty, with ghosts a bad second. I suppose the ghosts came directly or indirectly from stories, though certainly not from fairy stories, but I don't think the insects did. I don't know anything my parents could have done or left undone which would have saved me from the pincers, mandibles, and eyes of those many-legged abominations.
And that, as so many people have pointed out, is the difficulty. We do not know what will or will not frighten a child in this particular way. I say 'in this particular way' for we must here make a distinction. Those who say that children must not be frightened may mean two things. They may mean (1) that we must not do anything likely to give the child those haunting, disabling, pathological fears against which ordinary courage is helpless: in fact, phobias. His mind must, if possible, be kept clear of things he can't bear to think of. Or they may mean (2) that we must try to keep out of his mind the knowledge that he is born into a world of death, violence, wounds, adventure, heroism and cowardice, good and evil. If they mean the first I agree with them: but not if they mean the second. The second would indeed be to give children a false impression and feed them on escapism in the bad sense. There is something ludicrous in the idea of so educating a generation which is born to the Ogpu and the atomic bomb. Since it is so likely that they will meet cruel enemies, let them at least have heard of brave knights and heroic courage. Otherwise you are making their destiny not brighter but darker. Nor do most of us find that violence and bloodshed, in a story, produce any haunting dread in the minds of children. As far as that goes, I side impenitently with the human race against the modern reformer. Let there be wicked kings and beheadings, battles and dungeons, giants and dragons, and let villains be soundly killed at the end of the book.
~C.S. Lewis, Of Other Worlds, "On Three Ways of Writing for Children" (1966)