I've given up trying to make sense of Pelléas et Mélisande, and instead sees it as a emotional journey of Golaud, the only character that matters in this opera. People tend to characterize old Arkel as the wise one -- he's old, he's blind, and he doesn't involve himself in the affairs, but I think Golaud, despite his frequent fits of anger and jealously, manages to put his finger to the whole affair: Pelléas and Mélisande are mentally children, and it is their childish, self-centered behavior that brought their destruction and Golaud's torment.