Here's an excerpt (please refer to the original for sources, citations, and footnotes):
The Literature of Demonology and Witchcraft
By Edward Peters, Professor of History, University of Pennsylvania © 1998 Edward Peters
The literature of demonology and witchcraft produced between 1440 and 1750--some of the most important works of which are included on this website--constitutes a substantial source for the intellectual and cultural history of late medieval and early modern Europe and the Americas.
No longer considered as merely incidental to witch trial records, this literature has been integrated into the study, not only of demonology and witchcraft, but of an entire dimension of thought--what Sidney Anglo once characterized as, "a complex of interrelated magical ideas which informs many aspects of medieval and Renaissance thought."1 Among those aspects are women's and gender history, legal history--particularly of crime and punishment--theology, folklore, historical anthropology, sociology, and literature. Many writers of tracts on demonology and witchcraft also wrote on other subjects, some ostensibly far removed from witchcraft. Thus, the literature is connected not only to a variety of topics in early modern European and American history, but to the other intellectual interests of its authors that touch many disciplines.
THE ORIGINS OF THE OFFENCE OF WITCHCRAFT IN EUROPE
In European Christian cosmology as it developed from the epistles of Paul to the late seventeenth century, human nature was generally believed to be innately weak, sinful, and vulnerable to demonic temptation and deception. Although human reason--to the extent that it received divine grace and was properly instructed--could distinguish right from wrong, human will might not always choose the right.
Human ability to perceive and understand the world was also limited by the Fall. Those aspects of nature that humans could not perceive or understand could be manipulated, it was believed, by demons. Because these demons operated in natural realms beyond human intelligence, they could appear to work "wonders" and in doing so tempt humans, sometimes with God's permission. This was how the devil elicited homage of a kind properly paid only to God, and entered agreements with humans: by exhibiting and granting powers over nature and others not attainable by any other means, by performing acts that were not miracles,miracula, but rather mira, "wonders." All of these were ways of winning support from humans whose flawed perceptions and flexible wills would allow them to be led astray.
Servants of the devil could, on their own or with the devil acting through them, harm or illicitly influence other people or property by occult (meaning "hidden from humans," not "supernatural") means. Pact with the devil presumed the sins and crimes of idolatry and apostasy (renunciation of faith), because it constituted both a willful rejection of Christian baptism and the paying of sinful homage to the devil. The Latin word that designated harm caused to others by these means was maleficium, and it constituted the crime of witchcraft, establishing a link between it and demonology.
In addition to committing such acts, witches, it was said, evidenced other characteristics. They were thought to be identifiable (differently in different parts of Europe) because they might bear the mark of the devil on their bodies, have demonic companions (familiars), gather collectively to pay homage to the devil (at assemblies that came to be called the "synagogue" or "sabbath"), sacrifice infants, engage in acts of sexual promiscuity, and to be capable of flight and shapeshifting. Although not all writers on demonology and witchcraft subscribed to all of the aspects of the model for the offense of witchcraft here sketched, most did. The doctrines of demonology and witchcraft as they developed between 1300 and 1500, moreover, were consistent with the cosmology of the Church Fathers and later theologians and so appeared to be confirmed by scripture.
FROM MAGIC TO WITCHCRAFT
Until the fifteenth century witchcraft was not clearly distinguished from general sorcery or magic. Linguistically, this is still the case in French. In German Hexerei (witchcraft) was differentiated from Zauberei (magic, sorcery) in the early fifteenth century, and in Spanish this distinction was reflected in the terms hechicerÃa (sorcery) and brujerÃa (witchcraft). In English witchcraft--from the Old English wiccecraeft, which once meant divining, foretelling the future--was distinguished from magic/sorcery somewhat earlier.
Sorcery was consistently described and condemned in scripture, in the writings of the church fathers, especially St. Augustine [354-430] and Isidore of Seville [ca. 569-636], and later in theology, such as the work of Thomas Aquinas [ca. 1227-1274] and in canon law. Although sorcery was never the primary concern of the Church Fathers or medieval theologians before the fifteenth century, their work provided a comprehensive and contextual view of its function in the universe and in Christian cosmology.
Beginning in the twelfth century magic tended to divide into two types: learned magic, which was natural--and arguably neither sinful nor demonic--and sorcery proper, which was both. The division was shaped by the twelfth century influence of much Arabic (and much Greek via Arabic) learning into Latin learning. Under this influence, European thinkers began to view learned or natural magic as diabolical. From the twelfth through the seventeenth centuries, in fact, scholars undertook a vigorous debate concerning the validity of learned/natural magic. This raised some of the most important questions about spiritual causality that the period knew. As a consequence, sorcery, necromancy (the raising of the spirits of the dead), divination, and other forms of congress with the spirit world were all uniformly labelled as diabolical and came to be associated with a number of practices: healing, recovering lost or stolen objects, and harming one's neighbors. Witchcraft, learned demonology and other kinds of demonic magic became objects of widespread popular belief and were the charges behind most trials and condemnations during the period of the most intense persecutions, roughly from 1560 to 1660 ....