Book 1
2
As to whether we are to suppose that the substances as well as their qualities undergo this intimate mingling, as Zeno of Citium afterwards declared, I do not think it necessary to go further into this question in the present treatise;Note characteristic impatience with metaphysics. To Galen, as to Hippocrates and Aristotle, it sufficed to look on the qualitative differences apprehended by the senses as fundamental. Zeno of Citium was the founder of the Stoic school; on the further analysis by this school of the qualities into bodies cf. p. 144, note 3. for immediate purposes we only need to recognize the complete alteration of substance. In this way, nobody will suppose that bread represents a kind of meeting-placeA rallying-ground: lit. a place where two glens meet. for bone, flesh, nerve, and all the other parts, and that each of these subsequently becomes separated in the body and goes to join its own kind;Thus according to Gomperz (Greek Thinkers ), the hypothesis of Anaxagoras was that the bread...already contained the countless forms of matter as such which the human body displays. Their minuteness of size would withdraw them from our perception. For the defect or 'weakness' of the senses is the narrowness of their receptive area. These elusive particles are rendered visible and tangible by the process of nutrition, which combines them. before any separation takes place, the whole of the bread obviously becomes blood; (at any rate, if a man takes no other food for a prolonged period, he will have blood enclosed in his veins all the same).Therefore the blood must have come from the bread. The food from the alimentary canal was supposed by Galenn to be converted into blood in and by the portal veins. cf. p. 17. And clearly this disproves the view of those who consider the elementsBy elements is meant all homogenous, amorphous substances, such as metals, &c., as well as the elementary tissues.unchangeable, as also, for that matter, does the oil which is entirely used up in the flame of the lamp, or the faggots which, in a somewhat longer time, turn into fire.
