Necromancy is the act of conjuring the dead for divination. It dates back to Persia, Greece and Rome, and in the Middle Ages was widely practiced by magicians, sorcerers, and witches. It was condemned by the Catholic Church as "the agency of evil spirits," and in Elizabethan England was outlawed by the Witchcraft Act of 1604.
Necromancy is not to be confused with conjuring devils or demons for help. Necromancy is the seeking of the spirits of the dead. The spirits are sought because they, being without physical bodies, are no longer limited by the earthly plane. Therefore, it is thought these spirits have access to information of the past and future which is not available to the living. It has been used to help find sunken or buried treasure, and whether or not a person was murdered or died from other causes.
The practice of necromancy has been compared by some to modern mediumistic or practiced spiritualism. Many consider it a dangerous and repugnant practice. Dangerous because it is alleged that when some spirits take control of the medium they are reluctant to release their control for some time.
Necromancy is not practiced in Neo-pagan Witchcraft, but it is practiced in Voodoo.
There are two noted kinds of necromancy: the raising of the corpse itself, and the most common kind, the conjuring or summoning of the spirit of the corpse.