But while, on the one hand, the Christian church through the instrumentality of the monasteries was lending its aid to the preservation of the sources of medical knowledge, it was, on the other, doing its best to arrest all further evolution of that branch of science; not consciously, it must be admitted, but through a mistaken sense of its duty to God. Thus it came about that the Emperor Justinian I. (527–567 A. D.), acting under the narrow-minded advice of his ecclesiastical counsellors, closed the medical schools at Athens and Alexandria and at the same time withdrew the regular allowance of money which up to that time had been paid to the state physicians and to special scholars. A few years later, however (_i.e._, in the early part of the seventh century A. D.), some of the more highly educated physicians of Alexandria got together and made the attempt to organize a school of medicine in that city. A course of lectures was planned and sixteen of Galen’s works, carefully chosen for the purpose, were made the basis of the new course of instruction. The books selected were first carefully edited and simplified, and then commentaries were added in order that in their final shape these treatises might be better suited to the uses of students. The invasion of Alexandria by the Arabs, however, soon put an effectual stop to this promising attempt to revive Greek medicine. In this brief sketch I have thus far mentioned only the more direct effects produced by the new religion upon the evolution of medicine. The indirect effects, however, were also in some cases of very great importance. At the beginning of her history there developed in the Christian church, among her chief men, a strong disposition to quarrel over dogmas. To apply the term quarrelsomeness to this tendency may easily convey a wrong impression. It was, more strictly speaking, a highly developed conscientiousness on the part of men whose minds were deeply imbued with the idea that they were rendering God a service by keeping what they believed to be the true and only religion free from errors of all kinds. It took many centuries to impress the leaders of the church with the fact that the religion of Jesus Christ, like the science of medicine or the natural sciences, was capable of development to an almost indefinite extent; and it is owing to our appreciation of this important fact that we moderns look with so much more lenient eyes upon the distressing, not to say cruel, events of mediaeval ecclesiastical history. At the time of which I am now writing, however, it was considered highly unchristian--especially for one holding authority in the church--to believe otherwise than as her doctrines taught; and accordingly, in the early part of the fifth century A. D., Nestorius, the Patriarch of Constantinople, was deposed from his high office by a Council of the church and imprisoned because he was unwilling to teach the doctrine of the miraculous birth of Jesus Christ.