THE BEGINNINGS OF MEDICAL STUDY. The Greeks had made some progress in the beginnings of the study of disease (p. 47). Aristotle had given some anatomical knowledge in his writings on animals, and had theorized a little about the functions of the human body. The real founder of medical science, though, was Hippocrates, of the island of Cos (c. 460-367 B.C.), a contemporary of Plato. He was the first writer on the subject who attempted to base the practice of the healing art on careful observation and scientific principles. He substituted scientific reason for the wrath of offended deities as the causes of disease, and tried to offer proper remedies in place of sacrifices and prayers to the gods for cures. His descriptions of diseases were wonderfully accurate, and his treatments ruled medical practice for ages. [20] He knew, however, little as to anatomy. Another Greek writer, Galen [21](131-201 A.D.), wrote extensively on medicine and left an anatomical account of the human body which was unsurpassed for more than a thousand years. His work was known and used by the Saracens. Avicenna (980-1037), an eastern Mohammedan, wrote a _Canon of Medicine_ in which he summarized the work of all earlier writers, and gave a more minute description of symptoms than any preceding writer had done. These works, together with a few minor writings by teachers in Spain and Salerno, formed the basis of all medical knowledge until Vesalius published his _System of Human Anatomy_, in 1543. The Roman knowledge of medicine was based almost entirely on that of the Greeks, and after the rise of the Christians, with their new attitude toward earthly life and contempt for the human body, the science fell into disrepute and decay. Saint Augustine (354-430), in his great work on _The City of God_, speaks with some bitterness of "medical men who are called anatomists," and who "with a cruel zeal for science 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." [22] During the early Middle Ages the Greek medical knowledge practically disappeared, and in its place came the Christian theories of satanic influence, diabolic action, and divine punishment for sin. Correspondingly the cures were prayers at shrines and repositories of sacred relics and images, which were found all over Europe, and to which the injured or fever-stricken peasants hied themselves to make offerings and to pray, and then hope for a miracle.