A third condition is that the type of imagination must be persistent through fairly long periods of time, otherwise not only will there be an absence of sufficient feeling or momentum to cause the myths to be repeated and kept alive and transmitted to posterity, but the inducement to add to them and so enable them to mature and become complete and finished off and sufficiently attractive to Page 67appeal to the human mind in spite of the foreign character they often bear will be lacking. In other words, myths and legends grow. They resemble not so much the narrative of the story-teller or novelist as a gradually developing art like music, or a body of ideas like philosophy. They are human and natural, though they express the thought not of any one individual mind, but of the folk-soul, exemplifying in poetical form some great psychological or physiographical truth.