"On Fairy-Stories" by J. R. R. Tolkien

Some of my favorite quotes so far...

"For it is man who is, in contrast to fairies, supernatural... whereas they are natural, far more natural than he."

"For the trouble with the real folk of Faerie [land] is that they do not always look like what they are; and they put on the pride and beauty that we would fain wear ourselves. At least part of the magic that they wield for the good or evil of man is power to play on the desires of his body and his heart."

"The magic of Faerie is not an end in itself, its virtue is in its operations: among these are the satisfaction of certain primordial human desires. One of these desires is to survey the depths of space and time. Another is (as will be seen) to hold communion with other living things. A story may thus deal with the satisfaction of these desires... and in proportion as it succeeds it will approach the quality and have the flavour of fairy-story."