The Church, even in its earliest centuries, seems to have developed a distrust of them. Tertullian, in his "Treatise upon the Soul," stigmatizes the surgeon Herophilus as a "butcher," and evidently on account of his skill in his profession rather than on account of his want of it. St. Augustine, in his great treatise on the City of God, which remains to this day one of the treasures of the Church, speaks with some bitterness of "medical men who are called anatomists," and says that "with a cruel zeal for science they have dissected the bodies of the dead, and sometimes of sick persons, who have died under their knives, and have inhumanly pried into the secrets of the human body to learn the nature of disease and its exact seat, and how it might be cured!"[107] But it was not until the mixture of theology and science had begun to ferment, in the thirteenth century, and the ecclesiastical power had been aroused in behalf of this sacred mixture, that the feeling against medical science broke into open war. About the beginning of that century Pope Innocent III. forbade surgical operations by priests, deacons, or subdeacons. Pope Honorius went still further, and forbade medicine to be practised by archdeacons, priests, or deacons; in 1243 the Dominican authorities banished books on medicine from their monasteries; somewhat later, Pope Boniface VIII. interdicted dissection as sacrilege.[108] Toward the close of that great religious century came a battle which serves to show the spirit of the time. The great physician and chemist of the day was Arnold de Villa Nova. Although he has been overrated by some modern historians as a votary of the experimental method, and under-rated by others as a votary of alchemy, the sober judgment of the most thoughtful has acknowledged him as one of the most useful forerunners of modern masters in medical and chemical science. The missile usual in such cases was hurled at him. He was charged with sorcery and dealings with the devil. The Archbishop of Tarragona first excommunicated him and drove him from Spain; next he was driven from Paris, and took refuge at Montpellier; thence, too, he was driven, finally, every place in France was closed against him, and he became an outcast.[109] Such seemed the fate of men in that field who gained even a glimmer of new scientific truth. Even men like Cardan, and Paracelsus, and Porta, who yielded much to popular superstitions, were at once set upon if they ventured upon any other than the path which the Church thought sound--the insufficient path of Aristotelian investigation. We have seen that the weapons used against the astronomers were mainly the epithets "infidel" and "atheist." We have also seen that the missiles used against the chemists and physicians were the epithets "sorcerer" and "leaguer with the devil," and we have picked up on various battle-fields another effective weapon, the epithet "Mohammedan."