When a great number of pathological descriptions, sufficiently detailed, were collected, the embarrassment of such an accumulation began to be realized. Indeed, how could such a mass of material, arranged without any order, be made serviceable '? How find in this pell-mell the record they wished to consult - the tableau which answered best the symptoms of the disease before them ? No man's memory was equal to such a task.
In proportion as clinical observations multiplied, it became every day more necessary to arrange them after a method which would impress them upon the memory, and facilitate a recurrence to them when desirable. Such was the origin of the first pathological classification. The idea was suggested, as is seen, by the necessity of relieving the memory and the desire of facilitating researches. We are ignorant of the mode of classification first employed. We only know that, from the beginning of the philosophic period, diseases were arranged by groups, according to the locality affected, descending from the head to the feet. Fevers and other affections that attack the whole economy, or a great number of parts, at the same time, were arranged in separate groups. This disposition, which is met with in the works of Hippocrates, was adopted, with improvements and variations, down to an epoch not far from our own.
The first men who reflected on the phenomena of nature, in endeavoring to solve their causes, principles, and ends, did not imagine anything better to explain the movements of bodies and their continual trans- formations, than to people the universe with spirits ; that is, with invisible and impalpable substances endowed with force, intelligence and will, in different degrees. Each body was supposed to contain at least one of these spirits. This presided over and gave impulsion to all the changes and anatomical phenomena which occurred in the body to which it was attached. Man, whose organization is so complicated and whose functions are so numerous - whose intelligence is carried to the highest abstractions, to the idea of infinity - who is lost in the interpretation of the most simple phenomena, as the movement of the finger or the formation of an atom of matter - whose will controls the surrounding elements, but who cannot prevent a hair turning white man, I repeat, appeared to the early sages as a multiplied being, a little representation of the universe : consequently, his body was divided into many regions or departments, which were supposed to be governed by spirits of different orders. The system of Pythagoras, which we shall soon describe, offers the first example of this physiological polygarchy : it is the source whence are derived a multitude of ancient and modern theories.
From History of Medicine by P.V. Renouard M.D.