“Besides, since impotency in this act is sometimes due to coldness of nature, or some natural defect, it is asked how it is possible to distinguish whether it is due to witchcraft of not. Hostiensis gives the answer in his Summa (but this must not be publicly preached): When the member is in no way stirred, and can never perform the act of coition, this is a sign of frigidity of nature; but when it is stirred and becomes erect, but yet cannot perform, it is a sign of witchcraft.”