fortune. The ancient Hebrews, Greeks and Romans believed that spirits of the dead could return to haunt the living.
During the Dark Ages people believed in all manner of apparitions: demons, vampires and devil dogs. Around this time the Christian Church taught that ghosts were souls trapped in purgatory until they expiated their sins. The only apparitions that were holy and permitted by God were apparitions of religious figures, such as angels, saints and Jesus. All other apparitions, including spirits of the dead, were delusions created by Satan to confuse the living.
In seventeenth-century Europe apparitions of the dead played an important role as advisors to the living. Belief in ghosts fell out of favour in the eighteenth century, returning in the nineteenth with spiritualism, which espouses survival after death and mediumistic contact with the dead. Many motifs of apparitions appear in the folklore of different cultures, such as the Flying Dutchman or the ankou.
According to a study of apparitions by American psychical researcher Hornell Hart, published in 1956, there is no significant difference between apparitions of the living and of the dead. Apparitions can move through solid matter and appear and disappear abruptly. They can cast shadows. Some are corporeal and lifelike in their movement and speech while others are luminous or limited in movement and speech. Apparitions are typically dressed in clothing of their time. The majority of apparitions are thought to manifest for a reason, for instance, to communicate a crisis or death, give a warning, offer comfort or convey important information. Some haunting apparitions appear in places where emotional traumas have taken place, such as murders or battles, but other hauntings seem to be aimless.
Systematic studies of apparitions began with the Society for Psychical Research, London, in the late nineteenth century. By the 1980s polls in the Unites States conducted by the University of Chicago’s National Opinion Research Council showed a dramatic increase - around 78 per cent - in reported apparitions, perhaps due in part to changing public attitudes towards acknowledging paranormal experiences.
Although many ghost investigators have their own categories, the following are the most typical types:
A large number of theories have been put forward to explain apparitions, but none explain all the different types. Society for Psychical Research founders Edmund Gurney and Frederick Myers at first believed apparitions were mental hallucinations that had no physical reality either produced by telepathy from the dead to the living or projected out of the percipient’s mind in the form of an image. Gurney also believed that collective apparitions were a product of telepathy among the living, projected by the primary percipient to others around him or her. However, telepathy among the living does not explain why witnesses in collective sightings notice different details.
Myers, who believed strongly in survival after death, began to doubt the telepathic theory as early as 1885. In his landmark book Human Personality and Its Survival after Death (1903), he suggested that the apparitions consisted of a ‘phan-tasmogenic centre’, a locus of energies that could be perceived by the most psychically sensitive people. He conceived of a ‘subliminal consciousness‘ as the basis from which the consciousness springs and which survives the body after death. He theorized that the subliminal consciousness was receptive to extrasensory input and that apparitions appeared to psychically receptive people.
Other theories that have been advanced subsequently about apparitions suggest they are:
It is unlikely that any one theory can explain all apparitions,
