On the Sacred Disease
Hippocrates comments on the "sacred" disease declaring that it is no more sacred than other diseases. He stresses the importance of the disease having no relation with the divine whatsoever, but instead being purely of human origin. The author of On the Sacred Disease argues that even the most mysterious of diseases was still of natural cause and not of divine origin.
On the Sacred Disease is a work of the Hippocratic Corpus, written in 400 BCE. The authorship of this piece can not be confirmed and is therefore regarded as dubious. The treatise is thought to contain one of the first recorded observations of epilepsy in humans. The author explains these phenomena by the flux of the phlegm flowing from the brain into the veins rather than assigning them a divine origin. This turn from a supernatural to a naturalistic explanation is considered a major break in the history of medicine.
By these veins we draw in much breath, since they are the spiracles of our bodies inhaling air to themselves and distributing it to the rest of the body, and to the smaller veins, and they and afterwards exhale it. For the breath cannot be stationary, but it passes upward and downward, for if stopped and intercepted, the part where it is stopped becomes powerless. In proof of this, when, in sitting or lying, the small veins are compressed, so that the breath from the larger vein does not pass into them, the part is immediately seized with numbness; and it is so likewise with regard to the other veins.
ON THE SACRED DISEASE