The first of these theories, that of coction and crisis, is founded on the capital observation that there exists in the organized body an intrinsic force, diffused in all its parts, creating a mutual sympathy, and harmonizing their various functions for a common end, by a kind of instinct. One of the most distinct characters of this force is its
intermittence in regard to some of these functions, which is never seen in brute forces. These intermissions, which are seen in certain diseases.
produce in them periods, more or less regular, named critical periods or crises. But there are also many diseases in which these periods do not occur, or are not appreciable ; and the fault of the ancient Hippocratists consisted in extending the theory of crisis to all pathology.
Force, or vital forces, would appear to be inherent to the organs, being dependent entirely or in part on the constitution of these ; it was then essential to study that constitution ; but the Asclepiadae were prevented from proceeding to that study, by contemporaneous prejudices.
On the other hand, the vital or organic forces act upon the substances, liquid, solid, or gaseous, whether existing in the body or coming from without. These substances, endowed with properties more or less energetic, modify the functions of the organs, which made it necessary for the physician to be acquainted with their properties. Now, as physics and chemistry, which alone can furnish this knowledge, were too incomplete to afford the ancient physiologists but vague or false notions, the medical theories varied much in this respect.
The greater part of the naturalists of antiquity, recognised four primary forms of matter, and pretended to derive from them all the physical properties of the body. In like manner, the majority of the physicians supposed four cardinal humors, on which depended all the physiological and pathological phenomena.
Again, a small number of naturalists recognized but two. or even one element ; and also, following their example, a few physicians would only admit two physiological elements, and again, others only one.
In the midst of this conflict, a few men, more attentive, and less prejudiced, made the observation, that there is no proof that all material substances proceed from one or two, or four elements only, and that no one has ever seen the combination of a given dose of heat, cold, dryness, and humidity, engender either bitter, acid, sweet, or any other pretended secondary quality. They concluded that this division of the physical properties of bodies into primitive and secondary, was false, or at least hypothetical, and were desirous that only dogmas, which are experimentally demonstrated, should be admitted into the science. This was calculated to provoke a theoretic reform, for which the age was not yet prepared. We shall see its advent in the next period.
From History of Medicine by P.V. Renouard M.D.