On the Virginal Conception, and On Original Sin: Chapter 17
BASIC WRITINGS
own causes.Therefore,since these people were generated by means of the natural propagation granted to Adam,they neither can nor should at all be assimilated to the one whose miraculous conception we are now discussing, in such a way that it could be shown that they are free from the bondage of original sin.
Chapter 17 Why God was incarnate, given that he could have made from Adam a sufficient number of non-divine human beings without sin
Perhaps someone will say, "If a mere human being who was not God could have been made from Adam without any contagion of sin, as you claim, why was it necessary for God to be incarnate? God could have redeemed sinners through one such sinless man, or else, by a similar miracle, he could have created as many as were necessary to complete the heavenly city."
I shall respond to this briefly. God became a human being because a human being who was not God would not have been sufficient to redeem others, as I showed in the work I have mentioned so often.32 And he did not create as many human beings as were necessary because if no one who came about through natural propagation were saved, the nature that God had created in Adam would have been in vain; it would have seemed as if God were correcting a mistake that he had made.And it is not fitting for the highest wisdom to do this for any nature.
A little earlier33 I set out to investigate how we can understand that the seed received from the Virgin, in which (as has been shown) there was no sin, was free from all the necessities in which all other human beings are conceived. I was confident that if I could first establish by reason that it was exempt from the necessity of the sin and debt of Adam and of its more immediate ancestors, I would be able to show that it was free from all the other necessities— the inability to recover by one's own effort the justice that human nature abandoned, and the soul's being weighed down by the body that is corrupted, especially in infants—on the grounds that this human being was God.And so I began by asking how we could understand this to be true regarding the necessity of Adam's sin and debt, so that afterwards I might more easily discover what I was looking for in those other cases.And by the abundant grace of him whose sinless conception is our theme, not only have we come to know that he was free from all sin and debt and the necessities I have described, but in addition we have proved by intelligible reasoning that the human being
32 See Cur Deus Homo, Book 2, Chapter 6.
33 See Chapter 8.