A person's fear of the dark is not a manifest of the darkness itself but a certain characteristic about the darkness. This characteristic is that it alludes to the absence of a number of things that include: light, awareness, and comfort. Underneath all of the things that darkness is the absence of, it does create one thing, which is "the unknown". In essence people are afraid of the darkness because it instills that fear of the unknown, of not being in control and thereby those things whatever it may be can't be understood. Throughout history people have prosecuted and abominated things that they don't know or can't understand, like the witches in Salem for example. The same kind of human commonality (and some would say flaw) is present in the Anglo-Saxon heroic poem known as Beowulf. This specific misunderstanding is most prevalent with the monster Grendel, but is also noted with Grendel's mother and the Dragon.