No one can deceive you unless he makes you think 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 which never deceives at all. Children are not deceived by fairy-tales; they are often and 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 us are deceived by the Odyssey, the Kalevala, Beowulf, or Malory. The real danger lurks in sober-faced novels where all appears to be very probably but all is in fact contrived to put across some social or ethical or religious or anti-religious ‘comment on life’ … To be sure, no novel will deceive the best type of reader. He never mistakes art either for life or for philosophy. He can enter, while he reads, into each author’s point of view without either accepting or rejecting it, suspending when necessary his disbelief and (what is harder) his belief.
C.S. Lewis on Fact vs. Fiction (via poydrasreview)