C.S. Lewis: Children Are Never Deceived by Fairy-Tales

"Those who wish to be deceived always demand in what they read at least a superficial or apparent realism of content...[Without] at least some degree of realism in content...no deception will occur at all. No one can deceive you unless he makes you believe he is telling the truth. The unblushingly romantic has far less power to deceive than the apparently realistic. Admitted fantasy is precisely the kind of literature that never deceives at all. Children are not deceived by fairy-tales; they are often gravely deceived by school-stories. Adults are not deceived by science-fiction; they can be deceived by the stories in the women's magazines. None of is deceived by The Odyssey, the Kalevala, Beowulf, or Malory. The real danger lurks in sober-faced novels where all appears to be very probable but all is in fact contrived to put across some social or ethical or religious 'comment on life.'" 

--C.S. Lewis, An Experiment in Criticism (1961 A.D.)