St. Augustine On Romans 7

In regards to Romans chapter 7, how did Augustine interpret these verses?  In Augustine’s book titled Retractions we see that over his life he had two different interpretive views on this passage.  We read,
“When the apostle says: We know that the law is spiritual, but I am carnal, I did not want to understand this as in any way spoken by the apostle in his own name, because he was already spiritual, but rather with reference to a man who is subject to the law because he is not yet under grace. In this way I earlier understood these words, but later, having read several interpreters of the divine sayings whose authority impressed me greatly, I considered them more carefully and came to see that they can also be understood with reference to the apostle himself.”[1]
In other words, Augustine saw concupiscence (i.e. man's desire to sin) as the disorderly desire that remained as a punishment for Adam’s sin.  Therefore, Augustine saw Romans 7 as Paul simply showing that man’s nature is turned inward and is inclined to sin.  The Romans 7 discourse was interpreted as simple evidence of this lingering concupiscence that nags on within the believer.

[1] Saint Augustine, The Retractions (Catholic University of America Press, 1999), 104-106.