Hippocrates of Kos (cir.460 BC-380 BC) was an ancient Greek physician is often called "the father of medicine", and is know for writings an collection of writings of his name the Corpus Hippocraticum. The corpus was attributed to Hippocrates in antiquity, and its teaching followed principles of professionalism, natural theory, and rigorous practice of applying general diagnoses and passive treatment which was aimed to aid nature in restoring the sick to health. Hippocrates argued that diseases were caused by natural process within the body and not as a result of supernatural action or Gods and his natural philosophy and treatment approaches were emulated and idealized for centuries later.
The principle of naturalistic causes of disease and relying on natural philosophy was forcibly forwarded in the treatise 'Sacred Disease' which described the Hippocratic approach to epilepsy. The title, 'Sacred Disease' , is counter to the authors premise that epilepsy was in no way a sacred disease, but was simply a disorder of natural origin like other diseases. The writing opens with the assertion:
I do not believe that the 'Sacred Disease' is any more divine or sacred then any other disease but, on the contrary has specific characteristics and a definite cause. Nevertheless, because it is completely different from other disease, it has been regarded as a divine visitation by those who, being only human, view it with ignorance and astonishment.1
This strict application of science or natural philosophy toward the understanding of disease is present throughout the Hippocratic writings and is clearly stated in other treatise 'Tradition in Medicine'
Medicine has long possessed the qualities necessary to make a science. These are a starting point and a known method according to which many valuable discoveries have been made over a long period of time. By such method, too, the rest of the science will be discovered if anyone who is clever enough is versed in the observations of the past and makes these the starting point of his researches. If anyone should reject these and, casting them aside, endeavor to proceed by a new method and then assert that that he has made a discovery, he has been and is being deceived. 2
Basing the origin of disease on a understanding of the observable world as opposed to gods or spiritual possession made use of unyielding aspect of a natural philosophy and the idealized Hippocratic physician. This is because Galen's view of an ideal physician would be a practitioner that would apply scientific understanding to all processes and not set aside when dealing with hidden or poorly understood processes.