J.R.R. Tolkien
The author of this nonfiction essay, J.R.R. Tolkien is the well-known author of The Hobbit and The Lord of the Rings, an academic who also wrote many essays on literary criticism, fantasy, and Christianity. In this essay, he puts forward some of his views on fantasy and the particular literary form of the 'fairy-story,' giving an extensive definition and explanation as well as considering various examples and measuring them up to his standards. Tolkien's Christian beliefs have clearly influenced his philosophy concerning Fantasy, especially his theories of Creation and Sub-creation; his messages, however, are universally applicable, and they should be necessary reading for anyone interested in reading or writing fantasy.
God
As a Christian, Tolkien believes in God, and He figures into Tolkien's overarching philosophy about fantastic literature in a major way. Tolkien believes that God has created Man, and creation is an essential aspect of His nature. When humans engage in creative acts, therefore, they are exercising their faculties and participating in the nature of God, one of the truest forms of worship. By creating using the raw materials already created by God (physical and intellectual), Man therefore becomes a Sub-creator, acting in the image of God by the nature of the creative act.
Andrew Lang
Andrew Lang was a late 19th-century Scottish poet and literary critic who compiled many books of fairy-tales, which Tolkien references throughout "On Fairy-Stories." Lang is of particular significance to Tolkien's essay, as the essay was originally given as a speech for the annual Andrew Lang Lecture at the University of St. Andrews in 1939. Lang's legacy on the fairy-tale genre is extensive, but Tolkien takes his view and alters it slightly, presenting perhaps a more complete and compelling argument for the value of fairy-stories.
Aesop
Aesop was an ancient Greek storyteller who used anthropomorphic animals to teach lessons to children, using talking beasts to give listeners a moral lesson with each tale. Tolkien takes issue with Aesop, arguing that his works are no 'fairy-stories,' but are merely 'beast-fables,' a lesser form of art that ignores the transformative power of Faërie and limits the audience to children, rather than making them applicable to adults as well.
Jesus
In Christian tradition, Jesus is the Son of God who came down to Earth in human form, lived a perfect life, was executed, and rose back to life, redeeming sinful mankind through the shedding of his blood. In the Epilogue, Tolkien argues that this crucifixion/resurrection of Jesus was the greatest eucatastrophe of history: it seemed that Death had conquered God, but Jesus triumphed over the grave, resurrecting and saving humanity. All eucatastrophes are modeled after this one, as the desire for such stories is naturally infused into humanity as a result of this universal, divine paradigm.