Although it is customary to use the terms religion and science in any discussion about the interrelationships between these two broad subjects during the Middle Ages (c. 500-1500), it would be more accurate to substitute theology and natural philosophy, reserving science for the exact sciences that were dependent on mathematics: astronomy, optics, and mechanics. To these, the very inexact science of medicine might be added, since it was regarded as an independent discipline from the days of the great Greek physician Hippocrates in the fifth century BCE. If we confined our attention to the relations between religion and the exact sciences and medicine, there would be little to say, largely because there were no significant issues involving these subject areas during the Middle Ages.