Sometimes the theme is at the center of the book or a central character. He often shows a man who has to work very hard to marry a female who will make him happy since her qualities are not those the world respects. Or in a way Madame Max. People sometimes ask why people carry on reading Trollope. After all the world has changed so much.
Some inner values seem to have changed too.
We seem to be in the midst of a vast social or sexual rearrangement where there are different winners and losers than there used to be.