John concludes that many dreams are the work of demons.[479] Especially as of this sort he classifies the illusions of those who think that they have taken part during the night in witches’ Sabbats. “What they suffer in spirit they most wretchedly and falsely believe to have occurred in the body.”[480] And such dreams come mainly to women, feeble-minded men, and those weak in the Christian faith. Too much stress must not, however, be laid upon this apparent opposition to the witchcraft delusion.[481] John admits that the demons send dreams, and if he denies their verity, he merely repeats a hesitation as to the extent and reality of the power of demons over the body of men and the world of nature which we have frequently met in patristic literature and which is due to a natural reluctance to admit that their magic is as real as God’s miracles. [Sidenote: Prevalence of astrology.] From divination by dreams and demons John passes to astrology. To start with he admits the attraction which the art has for men of intellect in his own time. “Would,” he exclaims, “that the error of the _mathematici_ could be as readily removed from enlightened minds as the works of the demons fade before true faith and a sane consciousness of their illusions. But in it men go astray with the greater peril in that they seem to base their error upon nature’s firm foundation and reason’s strength.”[482] Beginning with mathematical and astronomical truths based on nature, reason and experience, they gradually slip into error, submitting human destiny to the stars and pretending to knowledge which belongs to God alone. [Sidenote: John’s attack upon it.] John ridicules the astrologers for attributing sex to the stars and stating the exact characteristics and influences of each planet, when they cannot agree among themselves whether the stars are composed of the four elements or some fifth essence, and when they are confounded by a schoolboy’s question whether the stars are hard or soft.[483] He grants that the sun’s heat and the moon’s control of humors as it waxes and wanes are potent forces, and that the other heavenly bodies are the causes of many utilities, and that from their position and signs the weather may be predicted. But he complains that the astrologers magnify the influence of the stars at the expense of God’s control of nature and of human free will. “They ascribe everything to their constellations.” Some have even reached such a degree of madness that they believe that “an image can be formed in accordance with the constellations so that it will receive the spirit of life at the nod of the stars and will reveal the secrets of hidden truth.”[484] Whether John has some magic automaton or merely an engraved astrological image in mind is not entirely clear. [Sidenote: Does astrology imply fatal necessity?]