We had no germs of religion, no conceptions of an unseen world.

We knew only the real world, and the things we feared were the real things, the concrete dangers, the flesh-and-blood animals that preyed.

It was they that made us afraid of the dark, for darkness was the time of the hunting animals.

It was then that they came out of their lairs and pounced upon one from the dark wherein they lurked invisible.
Possibly it was out of this fear of the real denizens of the dark that the fear of the unreal denizens was later to develop and to culminate in a whole and mighty unseen world.

As imagination grew it is likely that the fear of death increased until the Folk that were to come projected this fear into the dark and peopled it with spirits.