FIRST [PART]

...and [if a patient] should fall into a state of refinement original: "subtilitatem," referring here to the thinning or "subtlety" of bodily fluids, and soon, through such abundance and refinement, obstructions are created by any cause, and he is seized by a tertian fever a fever that recurs every third day, historically attributed to an excess of yellow bile; in this case, are there not two internal causes for the fever? Namely, one is the abundance of thin humors the four vital fluids—blood, phlegm, yellow bile, and black bile—that were believed to govern health, and the other is a putrid smokiness in the heart arising from those rotting humors, which actually produces the fever. The former cause Avicenna Ibn Sina (c. 980–1037), the Persian "Prince of Physicians" whose "Canon of Medicine" was the standard textbook for centuries most learnedly named the "antecedent" cause, and the latter the "conjoined" cause. But, lest I delay you with these matters, I shall proceed to my primary instruction.

Those primitive or evident causes must be considered, from which some curative intention can be drawn according to the essence or magnitude of the disease, or pertaining to the prognosis the forecast of the likely course and outcome of the disease. You shall also observe internal causes most diligently, distinguishing the antecedent from the conjoined where it is worthwhile. It is also necessary to know whether the cause is a bad "material" or "immaterial" complexion the unique balance of hot, cold, moist, and dry qualities in an individual, or an unnatural composition, or a "dissolution of unity" original: "unitatis dissolutio," a medical term for a physical break like a wound or fracture. You will also strive to recognize other differences, namely, which causes are "instrumental" and which are "fostering." All these things are understood through the senses and are better known to us, forming the principles of art and science according to the testimony of Aristotle the Greek philosopher whose logical works provided the framework for medieval and Renaissance science. For Galen Claudius Galenus (129–c. 216 AD), the most influential physician of the Roman Empire says in the second book of the Small Art original: "Artis Paruae," a nickname for his "Ars Medica" that it is beneficial to judge all things by the senses and not merely by the nature of things; otherwise, there is a danger that the patient may suffer permanent illness, which Avicenna also testifies to in the second [book] of the first [part of the Canon].

The signs known and sensed by us are those which either belong to the substance itself—which are recognized through touch and the pulse, or by quantity and number—or through "effects," such as impaired bodily functions and altered quality, or through those things called "causals," such as bowel excrement, urine, spit, sweat, and other superfluities. Galen speaks of all these in the second book of the Small Art, as does Avicenna in the second of the first. symptoms Furthermore, in the third place, one must recognize the "accidents" secondary symptoms or complications that result from a primary disease which follow a disease just as a shadow follows a body. Thus, when the disease is removed, the accidents also vanish, as is written by Galen in the eleventh book of his Method [of Healing]. Avicenna established this necessity in the first [book] of the first when he said it is necessary in medicine to know the accidents that occur in health and in sickness. For these accidents follow the disease and are removed along with it upon the disease's departure. However, sometimes by their own strength and malice, they either produce a worse disease or prostrate the patient's strength, even if this does not happen primarily or of its own accord. Therefore, since often by their own sharpness and malice...