I believe the correct answer is: He expresses the view that
marriage is a matter of custom or law rather than merely love.
In this excerpt from the novel “Monte Christo”, written by
Alexander Dumas, the cultural viewpoint which Fernand display is: the view that
marriage is a matter of custom or law rather than merely love, trying to gain
at least something in his favor, as Mercedes has declined his love for ten years.
This is best seen in Mercedes’ reply to him:
“You mistake Fernand; it is not law, but merely a custom,
and, I pray of you, do not cite this custom in your favor”.