Hippocrates, a Greek physician, is known as ‘the father of medicine’. He was born on the island of Cos where he later founded the first school of medicine. He lived between 460 BC to 377 BC. Modern medical students make a promise to be ethical in their work which is known as the Hippocratic Oath.
Doctors at the Hippocratic School of medicine were taught that diseases were the result of improper functioning of parts of the body, rather than of possession by demons as was believed superstitiously in those days. But Hippocrates and his followers did not know about the structure of the human body. They believed that diseases were caused by the imbalance of four vital fluids — blood, bile, phlegm and black bile. Hippocrates also pointed out that malaria and certain other diseases were associated with particular localities or climate conditions.
Hippocrates and other members of the school have written more than 50 books on medicine. Some of the descriptions of diseases in these books are very clear and accurate. In his writings, some of which may in fact be by other members of his circle, is found the important theory which tells that every disease is related to the natural law just like everything else and therefore should be carefully observed and treated accordingly. But this theory is not wholly accepted in modern medical science. However, no other medical books as scientific as these were written until modern times.