Chapter IX.--How Demons Get Power Over Men.
"Since, on the other hand, you are oppressed by strange sufferings inflicted by demons, on your removal from the body you shall have your souls also punished for ever; not indeed by God's inflicting vengeance, but because such is the judgment of evil deeds. For the demons, having power by means of the food given to them, are admitted into your bodies by your own hands; and lying hid there for a long time, they become blended with your souls. And through the carelessness of those who think not, or even wish not, to help themselves, upon the dissolution of their bodies, their souls being united to the demon, are of necessity borne by it into whatever places it pleases. And what is most terrible of all, when at the end of all things the demon is first consigned to the purifying fire, the soul which is mixed with it is under the necessity of being horribly punished, and the demon of being pleased. For the soul, being made of light, and not capable of bearing the heterogeneous flame of fire, is tortured; but the demon, being in the substance of his own kind, is greatly pleased, becoming the strong chain of the soul that he has swallowed up.
Chapter X.--How They are to Be Expelled.
"But the reason why the demons delight in entering into men's bodies is this. Being spirits, and having desires after meats and drinks, and sexual pleasures, but not being able to partake of these by reason of their being spirits, and wanting organs fitted for their enjoyment, they enter into the bodies of men, in order that, getting organs to minister to them, they may obtain the things that they wish, whether it be meat, by means of men's teeth, or sexual pleasure, by means of men's members. Hence, in order to the putting of demons to flight, the most useful help is abstinence, and fasting, and suffering of affliction. For if they enter into men's bodies for the sake of sharing pleasures, it is manifest that they are put to flight by suffering. But inasmuch as some, [1114] being of a more malignant kind, remain by the body that is undergoing punishment, though they are punished with it, therefore it is needful to have recourse to God by prayers and petitions, refraining from every occasion of impurity, that the hand of God may touch him for his cure, as being pure and faithful.
[1114] The gender is here changed, but the sense shows that the reference is still to the demons. I suppose the author forgot that in the preceding sentences he had written daimones (masc.) and not daimonia (neut.).
Chapter XI.--Unbelief the Demon's Stronghold.
"But it is necessary in our prayers to acknowledge that we have had recourse to God, and to bear witness, not to the apathy, but to the slowness of the demon. For all things are done to the believer, nothing to the unbeliever. Therefore the demons themselves, knowing the amount of faith of those of whom they take possession, measure their stay proportionately. Wherefore they stay permanently with the unbelieving, tarry for a while with the weak in faith; but with those who thoroughly believe, and who do good, they cannot remain even for a moment. For the soul being turned by faith, as it were, into the nature of water, quenches the demon as a spark of fire. The labour, therefore, of every one is to be solicitous about the putting to flight of his own demon. For, being mixed up with men's souls, they suggest to every one's mind desires after what things they please, in order that he may neglect his salvation.
Chapter XII.--Theory of Disease.
"Whence many, not knowing how they are influenced, consent to the evil thoughts suggested by the demons, as if they were the reasoning of their own souls. Wherefore they become less active to come to those who are able to save them, and do not know that they themselves are held captive by the deceiving demons. Therefore the demons who lurk in their souls induce them to think that it is not a demon that is distressing them, but a bodily disease, such as some acrid matter, or bile, or phlegm, or excess of blood, or inflammation of a membrane, or something else. But even if this were so, the case would not be altered of its being a kind of demon. For the universal and earthly soul, which enters on account of all kinds of food, being taken to excess by over-much food, is itself united to the spirit, as being cognate, which is the soul of man; and the material part of the food being united to the body, is left as a dreadful poison to it. Wherefore in all respects moderation is excellent.