Invocation of the supernatural is emphatically not an attempt to anticipate and prepare ourselves for ideas beyond our day to day experience, but rather an attempt to neutralize the horrors of the natural and the commonplace by casting the aspersion of non-reality upon them. Elements in the manifest world that disturb us are undermined by the invention of a supernatural correlate or substitute, which much less worrying to us, because it is supernatural and implausible, even if we still find it very frightening. Indeed the process of being frightened may be an important part of the reassurance it gives.
Ghosts, for example, do not address the question of survival, but rather the fear of the near approach of individuals whom we have failed to detect. By suggesting that the only way we can be approached in the security of our locked rooms is by walking supernaturally through a wall we are somehow reassured, even if we think we believe in the possibility. Similarly, the vampire may be a way of suggesting that human predation is not a normal but a supernatural event, whereas in fact it is all too commonplace. Indeed, in tales of the supernatural the everyday world is unusually benevolent, whereas the supernatural is usually very hostile to man. The function of the supernatural, then, is to make the natural seem by comparison at worst indifferent and at best positively charitable.