The Canon Episcopi, recorded about 900 AD, was used in witchcraft trails. Needless to say the Canon created about as many problems as it solved since it defined “witchcraft as Devil-worship but declared it to be nothing more than a foolish delusion.”
The Canon denied that witches could physically fly through the night, and said, “Whoever was ‘so stupid and foolish’ as to believe such fantastic tales was an infidel.” It claimed people believing such tales were deluded by the Devil. However, even though such flights and other feats were physically impossible, they could be achieved in spirit. And, whoever did such things in spirit were just as guilty as if they had done them physically.
By the 12th century the Canon was creating all sort of problems for demonologists. These men were accepting the validity of physical metamorphosis and transvection. The Canon pronounced these phenomena to be illusionary. “It was reasoned that even if witches flew with Diana and demons in spirit or imagination only, they were just as guilty as if they had done so in the flesh.”
From these deductions it was a simple thing to say all heretics including witches, whether physically or spiritually, formed pacts with the Devil. However, there were no defenses against such accusations for who can prove what he does or does not think or imagine? It was easy to accuse women of riding through the night upon beasts to sabbats and charging that lurid and demonic acts took place at such meetings.
Toward the mid-15th century the inquisitors and demonologists were beginning to dismiss the Canon Episcopi. It was presenting to many problems, however, it influence lingered on another 200 years. A.G.H.
Source: 4.