F. Godet, in yet another dusty volume left to me from my grandfather's library that I cracked into last night, on a helpful distinction between Galatians and Romans:
So little is it the object of the Apostle in the Epistle to the Romans to emphasize the contrast between Judeo-Christian legalism and his Gospel, that he begins with a description of the corruption of the pagan world, which would be altogether irrelevant on such a supposition. It is not, as in the Epistle to the Galatians, the powerlessness of the law to save man, which is the prevailing thought in the Epistle to the Romans, though that comes in incidentally. It is the powerlessness of man, as such, to save himself, whether with or without the law, and the necessity of salvation by Christ, which is the great theme of the Epistle to the Romans.
--Studies on the Epistles of St. Paul (London: 1889), 137-38