The extravagant credulity of the Milanese, and the fury and crimes which sprung from that credulity, may be partially excused on the ground that in that age even learned men believed in the possibility of exciting pestilence by means half–medical, half–magical, and that evil spirits exercised a malign influence over the air, and interfered visibly in diffusing the evil. More than thirty years later, the Jesuit Kircher, a man of various and extensive knowledge, but of a mystic temper, and a firm believer in the power of magic and occult influences, speaks of this plague as produced by the arts of evil men. Nor does he want authorities to strengthen his belief, among whom we may mention Theophrastus, who speaks of a terrible plague produced by poisoners in his own time, and gives the receipt for the pestiferous mixture, the ingredients of which are the putrid bodies of men deceased of the plague, and the bones, marrow, and poison of angry toads, approximating nearly to the receipt given by Ripamonte. To prove that demons may act as the ministers of God’s wrath to scatter the seeds of pestilence, he quotes Gregory of Nyssa, a father of the church in the fourth century, who relates in his Life of St. Gregory Thaumaturgus (the wonder–worker), that in a city of Greece, the people being collected in the theatre were much inconvenienced for want of room and made loud complaints, on which the evil spirit was to reply that there should soon be room enough in the city. And before the audience dispersed, so fierce a pestilence broke out among them, that in brief space a populous city was changed into a desert. Here the drift of the story is evident—it was a warning against theatrical amusements, which the Christians abhorred not only as profane, but as idolatrous, and a proof of the power of the devil over those who frequented them. The Pythagorean philosophers maintained similar doctrines as to the agency of spirits. Apollonius of Tyana, being at Ephesus during a pestilence, observed a demon under the habit of a fisherman busily employed in spreading the infection. He commanded that the fisherman should be stoned, and immediately the plague ceased. Similar stories are told of Pythagoras by Iamblichus. And the monkish writers helped mainly to encourage a belief of the interference of the devil in human affairs, by the many legends in which the spiritual adversary was introduced, to his own discomfiture and to the glory of some favourite saint.