Despite the fact that not all traditional literature has characters such as elves and fairies, it's still a very common element. Modern fantasy literature borrows from this tradition as well. For example, in "The Lord of the Rings," elves, dwarfs, trolls, orcs, goblins and hobbits all inhabit the world of man. The advantage using supernatural beings is that like the superhero comics, they allow the reader to explore difficult themes of self and society, but at a distance that feels safe.