TREATISE ON MEDICINE, BK. I. 3

Finally, one of his successors, Themison, having reached old age, has in turn departed from his doctrine in these recent times. These are the men to whom the medical profession has owed its greatest progress up to our time.

Of the three parts of medicine, the one that heals by regimen being the most difficult and the most elevated, it is fitting to begin with it. But as we encounter a divergence of opinion from the start—since some admit only the authority of facts, while in the eyes of others experience is insufficient if one does not join to it an intimate knowledge of the body and natural things—we are going to set forth the principal reasons put forward on both sides, so as to be able to give our personal opinion more easily. The partisans of rational medicine therefore posit as a principle that the physician must know the hidden and proximate causes, then the apparent causes of diseases; then know the natural actions, and lastly the composition of the internal organs. They call hidden causes those which lead one to investigate what are the principles of bodies, and what constitutes good and bad health; for it seems to them impossible to assign a suitable treatment to diseases whose source is unknown. Nor can one doubt that the treatment will change depending on whether the disease is recognized as having as its cause—as certain philosophers have wanted—the excess or the lack of one of the four elements. It will be different if one places the morbid principle in the fluids, with Herophilus, or in the pneuma vital spirit/breath, with Hippocrates; different if, as Erasistratus says, the blood, by spilling into the veins destined to receive the spirits, excites inflammation, which the Greeks call phlegmone inflammation, and if this inflammation raises a movement which is none other than fever; it will no longer be the same, finally, if, according to the opinion of Asclepiades, the atoms in circulation stop in the imperceptible pores of the body and determine their obstruction. He will therefore cure more surely who has not been mistaken about the primary cause of the disease. The necessity of experience is also recognized by the dogmatists: only, they say, one cannot arrive at it without the help of reasoning. And indeed, the ancient physicians did not order just anything for the sick; but after having maturely weighed what was most suitable for their state, they put to the test the means to which their conjectures had led them. That these means are today for the most part consecrated by usage matters little, if reasoning preceded their application; and this is also what happens in a great number of cases. Moreover, new diseases often appear on which experience has not yet been able to pronounce anything, and of which it is nevertheless necessary to seek the origin, given that, without this, no one in the world could find the reason which must make one prefer such a remedy to another. It is according to such considerations that they apply themselves to penetrating the causes wrapped in obscurity. Among the causes they call evident, they want to know if it is to the influence of heat or cold, of abstinence or dietary excess, or any other similar circumstance

that one must report the invasion of the disease; for if one has been able to trace back to the source of the evil, they think it will be easy to prevent the consequences. Under the name of natural actions of the body, they designate the phenomena of respiration, swallowing, digestion, and nutrition. They would also like to know for what reason the pulse of the arteries rises and falls alternately, and what other reason produces sleep and waking. In the ignorance of these causes, they estimate that no one has the power to prevent or heal the diseases that they have brought to birth. As digestion seems to play the principal role among these functions, they attach themselves to it particularly; and some, taking Erasistratus as a guide, believe that it takes place by trituration grinding/breaking down into particles; others, with Plistonicus, disciple of Praxagoras, think that it is by putrefaction; others finally, followers of Hippocrates, explain it by coction cooking/digestion by internal heat. But the students of Asclepiades arrive, declaring these ideas vain and devoid of foundation: matter is not subjected to coction; it passes to the state of crudity, and such as one has taken it, into the whole body of man. They are therefore little in agreement on this point, but they agree that the dietary regimen must vary according to the hypothesis admitted regarding digestion: if the foods are ground in the stomach, one must choose those which yield most easily to trituration; and if they putrefy, those which arrive most quickly at putrefaction; if there is coction of food by internal heat, it is to those which develop the most that one must stop; but there is no need to occupy oneself with this last choice if digestion does not...