[Translated in The works of Saint Augustine: a translation for the 21st century, Brooklyn, 1990.]
18, 19. When all this has been discussed and considered, it has to be concluded that those who listen to these things with faith should say to us what the Lord said: If that is how it is for someone who has a wife, it is better not to marry. And what answer shall we give them, except the answer he himself gave? What you say is not accepted by everyone, but only by those to whom it is granted. There are some who are born eunuchs; and there are others who are made eunuchs by man; and there are eunuchs who have made themselves eunuchs for the kingdom of heaven. Let anyone who is able to accept this accept it. So let anyone who is able to do so accept what is not accepted by everyone. It is able to be accepted by those to whom God in his mercy, mysterious but not unjust, grants the gift. Among all these who make themselves eunuchs for the kingdom of heaven, however, there are some, of both sexes, who have not known sexual union, and others who have experienced it and then turned away from it, in some cases indeed because it was an illicit experience, but also in others when it was licit. Moreover, among those whose experience was licit, there are some who only had experience that was licit, and others who had experience both licit and illicit. There are some whose experience has only been with their wives, but others who have had experience of other women and all kinds of perversions. Those, however, who make themselves eunuchs for the kingdom of heaven after the intimacy of marriage, do so either because they lose their partners through death, or because they practice celibacy together by agreement, or because it is made necessary by divorce. In this last case they make themselves eunuchs for the kingdom of heaven to avoid committing adultery by entering into a union with someone else while their husbands or wives are still alive. It is not to have greater glory in that kingdom, but because they cannot be there any other way. Those who are celibate not because of that necessity, but because they aspire to greater perfection, could be there also by maintaining marital chastity; even though it would be with less glory, they would still be there. Those, however, who stay celibate because they are afraid to marry again while their first husband or wife is still alive, ought to be more careful about their salvation than those who have chosen celibacy to obtain a greater reward. They will attain it if they are not guilty of adultery; but they will be guilty of adultery if they do not remain celibate, since any union with other persons while their first husband or wife is alive is not marriage but adultery. And if they are not in the kingdom of heaven, where will they be except in the place where they are not saved?