Martin Luther, as is well known, was a firm believer in the doctrine which held that the Devil was the originator of all diseases. No ailment, maintained the great reformer, comes from God, who is good, and does good to every one. It is the Devil who causes and performs all mischief, who interferes with all play and all arts, and who brings about pestilences and fevers. Luther believed that he himself was compelled, when his physical condition was out of order, to have a scuffle with the Evil One, and thereby obtain the mastery over him.[210:1] Tatian, the Syrian writer, of the second century, declared that the profligacy of demons had made use of the productions of nature for evil purposes. The demons, he wrote, do not cure, but by their art make men their captives. In that age, everybody, of whatever class or station in life, believed in the existence of demons, who were thought to be omnipresent, infesting men and the lower animals, as well as trees and rivers. At the time of the Reformation the same belief prevailed and was an important factor in influencing men's actions.[210:2] A belief in the personality of the Evil One is amply warranted by Scripture. What is not warranted, says a writer in "Social England,"[210:3] by anything in Holy Writ, is the medieval conception of Satan, ruling over a kingdom of darkness, in rivalry with God. Ignorance is guided by terror, rather than by love. To the undisciplined mind, whatever is supernatural or unexpected, makes a stronger appeal than the familiar phenomena of daily life. We cannot understand the motives and acts of our forefathers, wrote Henry C. Lea, in a "History of the Inquisition of the Middle Ages," unless we take into consideration the mental condition engendered by the consciousness of a daily and hourly personal contact with Satan. Charlatans were not unknown in the fifth century B. C. For the great Hippocrates inveighed against those who relied on amulets and charms as curative agents. In his view, the physician should possess a mind of such serenity and dignity as to be superior to superstition, for the latter is incompatible with a knowledge of the truth.[211:1] The Romans of old, who drove nails into the walls of the Temple of Jupiter, in the hope of warding off the Plague, employed thereby a quack remedy.