30. It seems the patriarchs had strictly forbidden to contract alliances with the offspring of Cain, just as, later, the Jews could not lawfully mingle with the Canaanites. Though there are not wanting those who write that incestuous marriages existed before the flood, blood-relationship being held to be no barrier, I yet infer from the fact that Peter has extolled the old world, that such incestuous atrocities did not exist at that time, but that the sin of the ancient world consisted rather in men marrying whom they pleased, and as many wives from the Cainites as they chose, ignoring parental authority and controlled alone by passion. It is, therefore, a harsh word—"All which they chose."
31. I have shown, on various occasions, that the two generations, or churches, of Adam and Cain were separate. For, as Moses clearly states, Adam expelled the murderer from his association. Without doubt, therefore, Adam also exhorted his offspring to avoid the church of the evil-doers and not to mingle with the accursed generation of Cain. And for a while his counsel or command was obeyed.
32. But when Adam died and the authority of the other patriarchs became an object of scorn, the sons of God who had the promise of the blessed seed and themselves belonged to the blessed seed, craved from the tribe of the ungodly, intercourse and espousal. He tersely calls the sons of the patriarchs the "sons of God," since to them was given the promise of the blessed seed and they constituted the true Church. Yielding to the corruptions of the Cainite church they indulged the flesh themselves and took from the tribe of Cain, as wives and mistresses, whom and as many as they chose. This Lamech and Noah saw with pain, and for that reason, perhaps, deferred entering upon marriage.
33. In reference to this point the Jews fancy foolish things. They interpret the sons of God to signify demon-lechers by whom that impious generation was begotten, and that they were called the sons of God by reason of their spiritual nature. The more moderate ones, however, refute such folly and represent the sons of the mighty. This has been aptly disproved by Lyra; for the punishment of the deluge befell, not alone the mighty, but all flesh, as shall the doom at the last day.
34. But as regards the demon-lechers and strumpets (incubi and succubi), I do not deny—nay, I believe—that a demon may be either a lecher or a strumpet, for I have heard men cite their own experience. Augustine says that he heard this from trustworthy people whom he was constrained to believe. Satan is pleased when he can deceive us in this manner, by assuming the form either of a young man or a young woman. But that anything may be begotten by a devil and a human being is simply false. We hear of monstrous births of demon-like features, and I have even seen some. I am of opinion, however, that they have been deformed by the devil, but not begotten: or that they are real devils with a human body either simulated or purloined. For if the devil, by divine permission, may take possession of the whole man and change his mind, is it strange that he may disfigure also his body, causing men to be born sightless or cripples?
35. Hence, the devil may so deceive frivolous people and such as live without the fear of God that when the devil is in bed, a young man may think that he has a girl with him, and a girl that she has a youth with her; but that anything may be born from such concubinage I do not believe. Many sorceresses have at one time or another been subjected to death at the stake on account of their intercourse with demons. If the devil can deceive eyes and ears so that they fancy they see and hear things which do not exist, how much easier is it for him to deceive the sense of touch, which is in this nature exceedingly gross! But enough! These explanations have no bearing upon the present text, and we have been led to them merely by Jewish babbling.