Nor is his book a polemic. Very little rhetoric is in here. This is hard core exegesis of the texts, with comparison across time with what has been preserved from ancient Egyptian, ancient Near Eastern, Greco-Roman, Judaic and early Christian writings. Such stuff is not everyone's cup of tea, but, hey, this is my field.
But the last chapter, where Gagnon takes on what all the scholars say who interpret the Bible in order to excuse homosexual practice, is just mind-choking. We're no longer talking linguistics, literature, textual analysis. We're talking logic. Claim and counterclaim. Begging questions, missing the point, logical fallacies. And every. single. claim raised by the scholars who have sounded off on this must be picked apart and answered, in excruciating and repetitive detail. The mind reels.
Anyway, it's an important book. It's just not an easy read, especially the last chapter.