Has de humoribus theses

8. Hippocrates ingeniously divided nutrition into three species: that which nourishes τὸ τρέφον, that which is like food οἷον, and that which is destined to be food μέλλον τροφὴν. From this source, that common division of the Arabs into primary and secondary humors seems to have flowed.

9. We call the primary χυμὸν humor, that is, that juice which still flows in the veins and arteries, which Hippocrates, as we said, calls that which is destined to be food, because it is not made fit for nourishing except through the intervention of many changes.

10. Chyle should not be considered as a primary humor, not only because it is in itself inept for nourishing the body or any part, as Avicenna’s commentators think (for by this reasoning, blood itself would not have to be considered a humor, which, unless it is greatly thickened and whitened, cannot nourish bones), but perhaps because it is not yet truly fluid, and is still very far from the act of nutrition.

11. The primary humor is unique, namely blood, which alone is contained in the veins, not mixed with other humors, as Montuus asserts, and by which alone all parts of the animal are nourished: The remaining humors are excrementitious, hostile to the parts, and therefore inept for nutrition, which Plato also affirms provide no food to the body ἀδεμίαν τροφὴν τῷ σώματι παρέχειν. Whence, if they are carried into the body with the blood, they infect it with a foul color and become the causes of diseases.

12. This opinion, besides being very ancient, is also sufficiently fortified with its own reasons, so that it cannot be easily refuted: Which Galen himself admits, and that this also pleased Galen can be a sign that Avicenna reproaches him for it.

13. This must be understood, however, regarding bodies enjoying complete health: For in an animal affected contrary to nature, it is most certain that those morbid excrements νοσερὰ πειττώματα, as Aristotle calls them, can be collected in the veins.