
Augustine of Hippo
Catena Aurea · Markusevangelium 7
And when he had called all the people unto him, he said unto them, Hearken unto me every one of you, and understand: There is nothing from without a man, that entering into him can defile him: but the things which come out of him, those are they that defile the man. If any man have ears to hear, let him hear. And when he was entered into the house from the people, his disciples asked him concerning the parable. And he saith unto them, Are ye so without understanding also? Do ye not perceive, that whatsoever thing from without entereth into the man, it cannot defile him; Because it entereth not into his heart, but into the belly, and goeth out into the draught, purging all meats? And he said, That which cometh out of the man, that defileth the man. For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders, Thefts, covetousness, wickedness, deceit, lasciviousness, an evil eye, blasphemy, pride, foolishness: All these evil things come from within, and defile the man.
(Lib. oct. Quæs. 73) For some things are joined to others in such a way as both to change and be changed, just as food, losing its former appearance, is both itself turned into our body, and we too are changed, and our strength is refreshed by it.b Further, a most subtle liquid, after the food has been prepared and digested in our veins, and other arteries, by some hidden channels, called from a Greek word, pores, passes through us, and goes into the draught.