The Bones of Avalon

Superstition requires credulity, just as true religion requires faith. Deep-rooted credulity is so powerful that it may even, in false beliefs, be thought to perform miracles. For if anyone believes most firmly that his religion is true, even if it is in fact false, he raises his spirit by reason of that very credulity until it becomes like the spirits who are the leaders and princes of that religion and seems to perform things which are not perceived by those in a normal and rational state.

Cornelius Agrippa (1486-1535),