In the fifteenth century, Christian demonology came to the consensus that witches could not perform magic without demonic assistance: History Essay, TCD, Ireland

In the fifteenth century, Christian demonology came to the consensus that witches could not perform magic without demonic assistance, but they had to promise to serve the devil if they wanted demons to carry out their designs

If witches were in league with the devil, they must also work with one another in covens, so the idea of a night flight to the witches’ sabbat was widely debated – could demons really make witches fly? Were they that powerful? What else could they achieve? Why did God let them? And what were good Christians to do about it?

Between 1450 and 1700 there were between 100,000 and 200,000 witch
trials. Between 40,000 and 60,000 were executed. Before and after these dates, there were very few trials, though people did believe in the existence of witches. The biggest challenge for historians is to work out what changed.

Already in 1324, a witch trial in Kilkenny reflected the idea that witchcraft was a form of heresy or demon-worship, but this notion seems only to have become widespread in the fifteenth century, owing to conspiracy theories
spread by learned demonologists.