Diexodus medica de hepatis

is the chief one that resides in the flesh of the liver; but others provide assistance: the attracting, the retaining, and the expelling faculties.

37. These faculties exert their acts through the fibers of the veins; for that which is succulent in the intestines is attracted, and that by the heat of the liver drawing it out, where the fibers rightly provide the service through their own contraction.

38. The material of the blood, led into its workshop, is fixed there by oblique fibers until it is elaborated by the heat therein and rendered as similar as possible to the substance of the liver through alteration. By itself, however, the heat produces a substance homogeneous in act, and simultaneously performs the secretion of residues, but by an adventitious force.

39. And a triple genus occurs here: two redundant in quantity: yellow bile, which is carried to the gallbladder; and feculent blood, which is carried to the spleen by its own paths, by a composite motion, with the expelling faculty of the liver and the attracting faculty of the receptacles concurring.

40. The third genus is of serous humor, which otherwise differs in kind from blood; but since with its mixture the blood becomes thinner—of the consistency that is needed in the subsequent narrowings—it is not separated until the blood has been carried into the vena cava.

41. Although, therefore, an organic form is required in number and the remaining accidents of the parts for the generation of nourishment, we nevertheless conclude that the ἀλλοίωσιν alteration, insofar as it is made into the species of blood, proceeds solely from the faculty of the flesh, and is effected only by its heat.

42. But the faculty of the soul, which exerts its act through the substance of the liver, seems to be defined only by that ἐντελεχεία actuality/fulfillment which is the completion of nourishment, not also that by which nutrition is actually performed; for this is the θρεπτικὴ δύναμις nutritive faculty which is wholly in every part of the whole.