Laws, both civil and ecclesiastical, against witchcraft practices and beliefs were enacted quite early in ancient Spain and Gaul in the early Christian Era. Charlemagne and other Frankish rulers condemned such practices and beliefs as evil and superstitious and passed severe laws against them, involving the death penalty. Church councils and leaders sometimes inveighed against belief in witchcraft as mere superstition and illusion, a contemptible relic of paganism; at other times they declared its practice was an actual evil that must be suppressed.

On the whole, though, with a few notable exceptions, such as Augustine and Thomas Aquinas, the ancient and medieval church attempted to wean its adherents from folk beliefs in witchcraft and magic. This skepticism, maintained by such influential figures as St. Boniface and St. Agobard, was officially embodied in canon law, which was comparatively moderate and lenient in its measures against witches and witchcraft.

Between the 12th and 15th centuries a decisive transformation occurred in the church's attitude. Contact with Arabic culture in the 12th century introduced studies such as alchemy and astrology that evoked a new interest in what has been called "natural magic," which, quite apart from the weapon it provided against heresy, could no longer be dismissed as peasant superstition. It was, however, agitation against heretics that finally caused a change in official church policy. In 1484 two Dominican friars, Heinrich Kraemer and Johann Sprenger, induced Pope Innocent VIII to issue a bull authorizing them to extirpate witchcraft in Germany; and two years later these two men published the Malleus maleficarum (The Witches' Hammer), a work that became the authoritative encyclopaedia of demonology throughout Christendom. It was a synthesis of folk beliefs that had hitherto been manifested in local outbursts of witchfinding. Its authority lasted for nearly three centuries, during the time of the European witch mania.

The demonology that the Malleus enshrined became an established and systematized theory attributing witches' powers to their special links with the devil, especially their sexual relationships with him as incubus (embodiment in masculine form) if they were women or as succubus (embodiment in feminine form) if they were men. Though witches in other societies personify evil in general, in European history they became specifically identified as the earthly representatives of the Prince of Evil.

The campaign against the devil's earthly representatives was waged long and unrelentingly. The biblical injunction "You shall not permit a sorceress to live" was observed repeatedly. The fomenting of the witch mania cannot be attributed exclusively to either Roman Catholic or Protestant leaders. Although launched by Roman Catholic evangelists, it was revived and extended by their Protestant counterparts and further cultivated during the Counter-Reformation. Although throughout the centuries of its sway there were skeptics who opposed its fundamental tenets, the mania did not decline until the whole medieval cosmology was displaced by that of the less theocratic and more secular frame of reference of the modern world. A.D.J. Macfarlane, a modern British historian of witchcraft during the Tudor and Stuart eras in England, has used the insights of modern Africanist anthropology to demonstrate the link between the witch mania and the broader social changes in which it was set. This he has done by reviewing more than 1,200 cases gleaned from court records and contemporary pamphlets relating to the English county of Essex in the 120 years following 1560. The most frequent kind of accusation of witchcraft was the one in which someone who had repudiated a neighbour, usually an old woman seeking a favour, subsequently attributed some misfortune befalling him to her anger at being refused and thus to her witchcraft. Macfarlane links this typical instance with the wider changes taking place from a neighbourly, highly integrated, mutually dependent village society to a more individualistic one of the kind now prevalent. In this general setting, the belief in witchcraft provided a means, though not necessarily one consciously employed, of sundering a close but redundant relationship.

The famous Salem witch trials of 1692 may be regarded as one of the last fitful flares of the witch mania. They have been studied anew by Chadwick Hansen, an American historian, who concluded that witchcraft was practiced in Salem, that it did harm to persons claimed to be victims, and that it posed a real threat to the community. The indiscriminate accusations that resulted in the execution of innocent people were the result of a general public panic in response to the psychosocial situation, not to the exhortations of clerical bigots. This fear sprang from a system of beliefs held by most Westerners at the time and also accounted for the harm done to the "afflicted" persons. Witchcraft worked in Salem because the persons involved believed in it.