Children know perfectly well that unicorns aren’t real, but they also know that books about unicorns, if they are good books, are true books. All too often, that’s more than Mummy and Daddy know; for, in denying their childhood, the adults have denied half their knowledge, and are left with the sad, sterile little fact: “Unicorns aren’t real.” And that fact is one that never got anybody anywhere (except in the story “The Unicorn in the Garden,” by another great fantasist, in which it is shown that a devotion to the unreality of unicorns may get you straight into the loony bin). It is by such statements as, “Once upon a time there was a dragon,” or “In a hole in the ground there lived a hobbit”—it is by such beautiful non-facts that we fantastic human beings may arrive, in our peculiar fashion, at the truth.
—Ursula K. Le Guin
—found in The Language of the Night (1979)