Book XIV. 638
Argument—Augustin again treats of the sin of the first man, and teaches that it is the cause of the carnal life and vicious affections of man. Especially he proves that the shame which accompanies lust is the just punishment of that disobedience, and inquires how man, if he had not sinned, would have been able without lust to propagate his kind.
This book is referred to in another work of Augustins (contra Advers. Legis et Prophet, i. 18), which was written about the year 420.