The other area, in which the Greek developments had a parallel in India, was medicine, although encouragement for this development in the two cases came from diametrically different sources. The Carukas and Susruras in India were roaming physiciarls who went about healing ordinary rural folk and fostered democratP: thinking and world views. Greek medicine, on the other hand, could continue its older -s because of the support it received from the aristocracy. In the era when Greek society was declining from the highest point of its achievement, wealthy citizens could not do without doctors as they led an increasingly unhealthy life of pleasure and abundance. We find that the Museum of Alexandria encouraged much research in anatomy and physiology. HippoeT;ites of Cos is a legendary figure in Greek medicine. His works, probably written sometime between 450 to 350 B.C., contain a clinical account of many diseases based on careful observations. Magical or religious causes or cures for diseases are not mentioned. However, the practice of medicine of the original Hippocratic school was superseded by the doctrine of four humours, firstly put'fonvard by EmpedocIes, an Ionian philosopher (see Fig. 3.16). His ideas proved very damaging to the practice and theory of medicine. A great doctor of those times, Herophihs (about 300 B.C.) based his work on observation and experiment. He was the first to understand the working of the nerves, distinguish between sensory and motor nerves, and make clinical use of the pulse. Erasistratics (about 280 B.C.) went further and noted the significance of the peculiar structure of the human brain. Unfortunately, most of the fine work of this period has been lost in its original form. But the essence of these findings was picked up and further developed by Galen (1 30-200 A.D.) who was born in Asia Minor but practised in Rome. Galen became a great founder of Arabic and medieval medicine with authority as great as that of Aristotle. He dissected animals and gained much anatomical knowledge. Galenical physiology described the ebbing and flowing of spirits, and blood in arteries and nerves, with the heart as the origin of heat, and the lungs as cooling fans. It provided a comprehensive, though rather unreal, view of human body. In terms of providing explanation of the phenomena, even Galen could not break out of the old doctrine of three spirits and souls, a doctrine which blocked any substantial advance in man's knowledge of his own body for another 1500 years.