Demonology is the science or doctrine concerning demons and is more often than not associated with theology—the science or doctrine about God. Along with this topic flow many false and dangerous forms of study, fitly adapted to the old words of Albertus Magnus: A daemonibus docetur, de daemonibus docet, et ad daemones ducit ("It is taught by the demons, it teaches about the demons, and it leads to the demons").

The majority of the literature placed under demonology is tainted with errors that may in fact owe their origin to ‘the father of falsehood’, and furthermore (especially the more practical portions—ascetical and mystical demonology) is designed to lead men to give theirselves to the service of Satan.
The truest doctrine about demons and evil spirits is namely Catholic theology which deals with the creation and fall of the rebelled angels, and which deals with the various ways in which these fallen spirits are permitted to tempt and afflict the children of men. These pages deal with some generally more major systems throughout the various lands and distant ages.

I hope that this will enable you to further appreciate the important part played by these ideas in human history, and their influence on religion, morals and social life. I have tried to distinguish the figments of truth from this vast weave of falsehood—truths of natural religion; recorded experience; actual facts; and a little teaching which has remained and been revealed from Jewish and Christian Scriptures or primitive tradition.

Belief in evil spirits; attempts to propitiate them and avert their wrath; securing their favour and assistance—these are many accounts which readers identify with after beginning to study Demonology.
It has started with all spirits being first conceived of as being the souls of dead men, and from this aboriginal Animism it has gradually developed into the various elaborate systems of mythology, demonology, and angelology we have today.

Assyrian and Akkadian Demonology

Iranian Demonology

Jewish Demonology

Early Christian Demonology

Medieval to Modern Demonology

The Book of Enoch

The Nephilim

Demons | Fallen Angels | Succubi