The "father of medicine" is a title well-earned by Hippocrates. Defying priests' assumption in Greece (circa 430 BC) that the Gods caused various diseases, Hippocrates established as fact that medical science was the appropriate means to assist the ill and infirm. "Men believe only that it is a divine disease because of their ignorance and amazement." (The Sacred Disease).
Starting with Hippocrates as originating author, the ancient Greeks created the Hippocratic Collection of medical references (> 60 tomes). At the base of this learning was the realization that shrewd observation of symptoms and deductive reasoning were key fundamentals of medical practice. "First of all the doctor should look at the patient’s face. If he looks his usual self this is a good sign. If not, however, the following are bad signs – sharp nose, hollow eyes, cold ears, dry skin on the forehead, strange face colour such as green, black, red or lead coloured. If the face is like this at the beginning of the illness, the doctor must ask the patient if he has lost sleep, or had diarrhoea, or not eaten." (On forecasting diseases).
Hippocrates insistence on what would later be termed "clinical observation" was profound. Today all practitioners are required to take the Hippocratic Oath, in remembrance of his efforts. Courageous, focused and dedicated, Hippocrates was a remarkable individual, helping separate the supernatural from the practice of medicine.
Numerous example readings are available on-line).