I find that there really are human beings who think fairy tales bad for children. I do not speak of the man in the green tie, for him I can never count truly human. But a lady has written me an earnest letter saying that fairy tales ought not to be taught to children even if they are true. She says that it is cruel to tell children fairy tales, because it frightens them. You might just as well say that it is cruel to give girls sentimental novels because it makes them cry. All this kind of talk is based on that complete forgetting of what a child is like which has been the firm foundation of so many educational schemes. If you keep bogies and goblins away from children they would make them up for themselves. One small child in the dark can invent more hells than Swedenborg. One small child can imagine monsters too big and black to get into any picture, and give them names too unearthly and cacophonous to have occurred in the cries of any lunatic. The child, to begin with, commonly likes horrors, and he continues to indulge in them even when he does not like them. There is just as much difficulty in saying exactly where pure pain begins in his case, as there is in ours when we walk of our own free will into the torture-chamber of a great tragedy. The fear does not come from fairy tales; the fear comes from the universe of the soul.
The timidity of the child or the savage is entirely reasonable; they are alarmed at this world, because this world is a very alarming place. They dislike being alone because it is verily and indeed an awful idea to be alone. Barbarians fear the unknown for the same reason that Agnostics worship it—because it is a fact. Fairy tales, then, are not responsible for producing in children fear, or any of the shapes of fear; fairy tales do not give the child the idea of the evil or the ugly; that is in the child already, because it is in the world already. Fairy tales do not give the child his first idea of bogey. What fairy tales give the child is his first clear idea of the possible defeat of bogey. The baby has known the dragon intimately ever since he had an imagination. What the fairy tale provides for him is a St. George to kill the dragon.
― G.K. Chesterton, Tremendous Trifles
I had come across a Neil Gaiman’s quote that paraphrased this above passage.
Fairy tales are not true. They are more than true. Not because they tell us that dragons exist, but because they tell us that dragons can be defeated.