The question is whether it is possible to distinguish between fantasy and true science fiction. I remember the analogy, attributable I believe to Theodore Sturgeon, of the elf climbing vertically along a brick wall. In a science fiction story, the elf's knees would be bent, his center of gravity projected forward, his hat hanging down to his neck, and his feet would most likely be equipped with some sort of suction cups. In a fantasy, on the other hand, the elf would simply climb the wall in a normal walking posture, with his stocking cap raised straight up on his forehead. What is the difference between these scenarios? The typical answer is that the science fiction story must respect the implicit rules of the universe; in this case, gravity. However, fantasy does not need to “doff its hat” to the law of universal gravitation; the story can bend the rules that give it the fantasy genre. But what happens if, for a specific reason, near the elf on the wall? , the gravitational force vector is simply perpendicular to the side of the wall rather than parallel to it? In this case, the behavior of the elf in the fantasy would be in perfect agreement with physical law. We could then say that the fantasy is actually science fiction since we have provided a “scientific” explanation of the elf’s behavior. Science fiction and mainstream fiction explore the political and social implications of religion. The main difference is in the setting. Science fiction considers what religion can become under significantly changed circumstances. Leigh Brackett, The Long Tomorrow (1955), suggests the possibility that one religion may better prepare its followers for post-Holocaust existence than others. Kate Wilhelm Let the Fire Fall (1969) takes place in a future United States swept by millennial fanaticism. Frank Herbert's Dune stories examine in depth the effects of political power wielded by figures considered divine (Martin 1981). This is certainly not a comprehensive list of how science fiction authors treat the topic of religion. But it suggests a much deeper and broader interest in the theme than many have wanted to acknowledge. Until now, literary criticism has not sufficiently taken this fact into account. In light of the cultural influences already mentioned, these essays overall take a generally Christian and theological approach to the subject..