Book 2
3
Thus, every hypothesis of channels Or ducts, canals, conduits, i.e. morphological factors. as an explanation of natural functioning is perfect nonsense. For, if there were not an inborn faculty given by Nature to each one of the organs at the very beginning, then animals could not continue to live even for a few days, far less for the number of years which they actually do. For let us suppose they were under no guardianship, lacking in creative ingenuityOr artistic skill, artistry. cf. Book I., chap. xii. and forethought; let us suppose they were steered only by material forces, Only; cf. Introd., p. xxviii. and not by any special faculties (the one attracting what is proper to it, another rejecting what is foreign, and yet another causing alteration and adhesion of the matter destined to nourish it); if we suppose this, I am sure it would be ridiculous for us to discuss natural, or, still more, psychical, activities — or, in fact, life as a whole.Note how Galen, although he has not yet clearly differentiated physiological from physical processes (both are natural) yet separates them definitely from the psychical. cf. p. 2, footnote. A psychical function or activity is, in Latin, actio animalis (from anima =psyche ).
3
For there is not a single animal which could live or endure for the shortest time if, possessing within itself so many different parts, it did not employ faculties which were attractive of what is appropriate, eliminative of what is foreign, and alterative of what is destined for nutrition. On the other hand, if we have these faculties, we no longer need channels, little or big, resting on an unproven hypothesis, for explaining the secretion of urine and bile, and the conception of some favourable situation (in which point alone Erasistratus shows some common sense, since he does regard all the parts of the body as having been well and truly placed and shaped by Nature).
