Early Christianity, from the outset, was subjected to the influence of ancient false ideas on the subject of demons. Without making any modifications whatever, it had appropriated this false doctrine, and had deduced from it the same medical notions as paganism had done. The New Testament exhibits numerous examples of a prevailing belief that supernatural beings—_i.e._, demons—were frequently the cause of bodily ailments; and as Christ and His disciples had often cured such patients, it follows that the belief in demons and their relations to pathology must have been widely disseminated among the Christians of that period. The Church Fathers also bear witness to this fact, as they, in their writings, acknowledge, in plain terms, the belief in demons as causes of disease. Justin Martyr, Tatian, Tertullian, Origen, Augustin, all mention demons and their power over the human body (compare Harnack, Chapter V., page 68, etc., where these conditions are most lucidly depicted). Thus, for instance, St. Augustine says: “_Accipiunt (scilicet dæmones) enim sæpe potestatem et morbos immittere et ipsum aerem vitiando morbidum reddere._” And, indeed, early Christianity not only accepted pagan demonology unchanged, it even increased the therapeutic aspect of this delusion in a most regrettable manner. This belief in demons, under the influence of Christian doctrines, developed into an epidemic of insanity which prevailed unrestrictedly for two or three centuries, and which was again awakened in the late middle ages, to grow at last into one of the most terrible aberrations of the human mind—into the belief in witches.