Necromancy is divination by means of the spirits of the dead: from the Greek words 'necro' meaning 'dead' and `manteria', meaning divination')

The illustration to the right depicts scientist, Dr. John Dee, with his assistant Edward Kelly, communicating with the dead in a cemetery at midnight.  Dr. Dee is said to be the cornerstone of all modern occutism, spiritualism and hypnosis.
It is through its Italian form of the word, nigromancia, that it came to be known as the "Black Art". With the Greeks it originally signified the descent into Hades in order to consult the dead rather than summoning the dead into the mortal sphere again. The art is of almost universal usage. There are two clear divisions of necromancy however, that branch in which one takes the spirit within oneself (channeling) and that in which one consults directly with the corpse or spirit. The second method led to the disinterment of corpses and rifling of graves for the grisly charms which magicians and witches considered necessary for the effective performance of the magical arts.  Therefore there is much controversy among modern adepts as to the exact methods to be properly pursued in the necromantic art.

Many believe that to evoke the dead the magician needs to obtain the help of powerful spirits, both for his own protection and to compel the corpse or ghost to submit to his will. A spell from ancient Greece calls upon the powers of the mighty Kore, Persephone, Ereshkigal, Adonis, Hermes and Thoth, to bind the dead. According to a ritual described by Seneca, the Roman dramatist, the summoning of the dead involved not only a burnt sacrifice but a blood-drenched altar. 

It must be borne in mind the necromancy, which in the Middle Ages was called sorcery, shades into modern spiritualistic practice. There is no doubt, however, that necromancy is the touchstone of occultism, for if, after careful preparation the adept can carry through to a successful issue, the raising of the soul from the other world, he has proved the value of his art. It would be fruitless in this place to enter into a psychological discussion as to whether the feat is possible of accomplishment or not, and we will confine ourselves tit he material which has been placed at our disposal by the sages of the past, who have left full details as to how the process should be approached. In the case of a compact between the conjuror and the devil, no ceremony is necessary, as the familiar is ever at hand to do the behests of his masters. This, however, is never the case with the true sorcerer, who preserves his independence, and trusts to his profound knowledge of the art and his powers of command; his object therefore is to 'constrain' some spirit to appear before him, and to guard himself from the danger of provoking such beings. The magician, it must be understood, always has an assistant, and every article named is prepared according to rules well known in the black art. In the first place, they are to fix upon a spot proper for such purpose; which must be either in a subterraneous vault, hung around with black, and lighted by a magical torch; or else in the center of some thick wood or desert, or upon some extensive, unfrequented plain, where several roads meet, or amidst the ruins of ancient castles, abbeys, monasteries, etc., or amongst the rocks on the sea shore, in some private detached churchyard, or any other solemn, melancholy place between the hours of twelve and one in the night, either when the moon shines very bright, or else when the elements are disturbed with storms, thunder, lightning, wind, and rain; for, in these places, times, and seasons, it is contended that spirits can with less difficulty manifest themselves to mortal eyes, and continue visible with the least pain, in this elemental external world. When the proper time and place is fixed on, a magic circle is to be formed, within which, the master and his associate are carefully to retire. The dimensions of the circle are as follow: - A piece of ground is usually chosen, nine feet square, at the full extent of which parallel lines are drawn within the other, having sundry crosses and triangles described between them, close to which is formed the first or outer circle, then, about half-a-foot within the same, a second circle is described, and within that another square correspondent to the first, the center of which is the seat of spot where the master and associate 843 are to be placed. "The vacancies formed by the various lines and angles of the figure are filled up with the holy names of God, having crosses and triangles described between them. The reason assigned by magicians and others for this institution and use of circles, is, that so much ground being blessed and consecrated by such holy words and ceremonies as they make use of forming it, hath a secret force to expel all evil spirits from the bounds thereof, and, being sprinkled with pure, sanctified water, the ground is purified from all uncleanliness; besides, the holy names of God being written over every part of it, its force becomes so powerful that no evil spirit hath ability to break through it, or to get at the magician and his companion, by reason of the antipathy in nature they bear to these sacred names. And the reason given for the triangles is, that if the spirit be not easily brought to speak the truth, they may by the exorcist be conjured to enter the same, where, by virtue of the names of the essence and divinity of God, they can speak nothing but what is true and right. The circle, therefore, according to this account of it, is the principal fort and shield of the magician, from which he is not, at the peril of his life, to depart, till he has completely dismissed the spirit, particularly if he be of a fiery or infernal nature.