Hugo characterizes the relationship between Claude as that of a mother to a son. This is apparent when Claude adopts Quasimodo on the assumption that the good deed will pay for Jehan's sins. In return for the priest's kindness, Quasimodo develops a singular loyalty and affection for Claude. As the story unfolds Hugo uses these interpersonal dynamics to create tension and underscore the passionate feels awakened when questions of obedience arise. The priest, one of the most learned men in the city and the hunchback, perhaps the most ignorant, have a unique relationship. Though the priest does save Quasimodo's life and provides a place for him it is for the selfish motive of buying a place in heaven for his brother. Frollo does not have any real affection for the hunchback who worships him and lives only to please him. Quaismodo's interactions are limited to the bells, the statues and Frollo, the only things in his life that have not recoiled from his ugliness. Frollo's icy disposition and Quasimodo's ugliness make them both social outcasts.
The Hunchback of Notre-Dame: Novel Summary: Book IV Analysis