Nicene and Post-Nicene Fathers, Vol. II:
City of God: Chapter 21

Chapter 21.—That Man’s Transgression Did Not Annul the Blessing of Fecundity Pronounced Upon Man Before He Sinned But Infected It with the Disease of Lust.

Far be it, then, from us to suppose that our first parents in Paradise felt that lust which caused them afterwards to blush and hide their nakedness, or that by its means they should have fulfilled the benediction of God, “Increase and multiply and replenish the earth;” 750 for it was after sin that lust began.  It was after sin that our nature, having lost the power it had over the whole body, but not having lost all shame, perceived, noticed, blushed at, and covered it.  But that blessing upon marriage, which encouraged them to increase and multiply and replenish the earth, though it continued even after they had sinned, was yet given before they sinned, in order that the procreation of children might be recognized as part of the glory of marriage, and not of the punishment of sin.  But now, men being ignorant of the blessedness of Paradise, suppose that children could not have been begotten there in any other way than they know them to be begotten now, i.e., by lust, at which even honorable marriage blushes; some not simply rejecting, but sceptically deriding the divine Scriptures, in which we read that our first parents, after they sinned, were ashamed of their nakedness, and covered it; while others, though they accept and honor Scripture, yet conceive that this expression, “Increase and multiply,” refers not to carnal fecundity, because a similar expression is used of the soul in the words, “Thou wilt multiply me with strength in my soul;” 751 and so, too, in the words which follow in Genesis, “And replenish the earth, and subdue it,” they understand by the earth the body which the soul fills with its presence, and which it rules over when it is multiplied in strength.  And they hold that children could no more then than now be begotten without lust, which, after sin, was kindled, observed, blushed for, and covered; and even that children would not have been born in Paradise, but only outside of it, as in fact it turned out.  For it was after they were expelled from it that they came together to beget children, and begot them.

Footnotes

Gen. 1.28.

Ps. 138.3.