G O E C I A
"Frequently, and in several societies, evil is seen as a conscious strength, and felt as if it were personified. Out of a matter of simplicity and clearness, I have called this personification "the Devil". Evil is never abstract. It should be always understood in terms of a person's suffering(passage of Ivã's speech to Aliosha in Dostoiewski's Karamazov Brothers.).
"Imagine a shaking mother with her son in her arms, and a circle of turkish invaders nearby. They have plotted an aniusement: They play with the baby, they laugh to make him laugh. They succeed, the child's face. She laughs with contentment, puts out the litle hands to the pistol, and the turk pulls the trigger on the child's face, blowing out his brains. I think that if the devil doesn't exist, but was created by man, was after his image and likeness." (passage of the book the Devil by Jefrey Burton Russel)
Goecia is a greek termination for black magic, necromancy, arts of malefactions, sortileges and spells. However, a priori, Magic is the great science. Mother of all.
"The magic consists in adoring the gods and it is obtained through this adoration", says Plato.
Gods, which in fact, are the Nature's hidden powers, personified by the learned and lighted priests - hierophants - ,in which is venerated only the First cause's attributes, to which, in locom are given several names, including God.
Magic is the science of communicating with supreme and supramundane powers and direct them, as well as dominating those from inferior spheres; it is a practical Knowledge of Nature's hidden mysteries only Known by a few, just because it is difficult to learn without running into mistakes, producing psychic troubles and disastrous failures to those who aren't qualified or without an inspired's guidance.
The middle Age's mystics, according to concepts of the Church, divided the magic into three categories: Theurgy, Goecia and Natural Magic. As a matter of fact, all three form as unity.
The Goecia(black magic) and the Natural(white magic) raised themselves to the highest levels of precise and progressive learning. The material and realistic desires of modern times have added to discredit magic, and to submit it to myth, in some cases in a ridiculous manner.