The causes of this change (of which I think an explanation is due) are as follows. […] Many changes in the natural world have also been effected by the Saints, according to the popular creed in most parts of Europe. […] Priests, philosophers, and poets combined to vary, change, and modify them. […] Finally, the change of religious ideas gradually affected Erebos, the abode of the dead. […] It is thus that mythology changes with modes of life.