To the ancient Greeks daemons, from the Greek word daimon meaning 'divine power', 'fate' or 'god', were intermediary spirits between the gods and humankind, rather like guardian spirits. They could be either good or evil. Good daemons were supportive and encouraging but evil daemons could lead people astray with bad counsel.

The Christian Church labeled all such pagan spirits as evil, which is why daemons, better known to us today as demons, are traditionally associated with evil. For centuries demons have been blamed for a host of ills and misfortunes including demonic sexual molestation, where a demon masquerades as a man or woman to molest its victim. Many possession cases in the Middle Ages involved sexual molestation by demons, although this may have been more to do with repressed humans than supernatural activity. In many cultures and religions demons have been exorcised. In Catholicism cases of demonic possession - in which demons battle for a person's soul - are dealt with by formal exorcism rites that date back to 1614.