After passing through a stage when he was too preoccupied with his material cares and wants to consider whether he was haunted or not, early man in the Celtic world as elsewhere, after long epochs of vague unrest, came to realise that he was somehow haunted in the daytime as well as at night, and it was this sense of being haunted that impelled his intellect and his imagination to seek some explanation of his feelings.

Primitive man came to seek a solution not of the Universe as a whole (for of this he had no conception), but of the local Universe, in which he played a part.

In dealing with Celtic folk-lore, it is very remarkable how it mirrors the characteristic local colouring and scenery of the districts in which it has originated.

In a country like Wales, for example, it is the folk-lore of springs, caves, mountains, lakes, islands, and the forms of its imagination, here as elsewhere, reflect unmistakably the land of its origin.

Where it depicts an 'other world,' that 'other world' is either on an island or it is a land beneath the sea, a lake, or a river, or it is approachable only through some cave or opening in the earth.