Why does Mary use to form her narrative in "Frankenstein"?

Instead of beginning with Victor's point of view, Shelley introduces us to Walton first. Using a frame device, in which the tale is told to us by someone who reads it or hears it from someone else, Shelley invites readers to believe Victor's story through an objective person. Shelley also uses an important literary device known as the epistolary form—where letters tell the story—using letters between Walton and his sister to frame both Victor's and the creature's narrative. Before the novel's first chapter, Walton writes to his sister about the "wretched man" he meets, building suspense about the "demon" Victor mentions at the beginning of his narrative. Once Victor begins telling his story, we slowly learn about his childhood and the eventful moments leading up to his studies at the University. Then, the creature interrupts Victor, and we get to hear all the significant moments leading up to his request for a partner. Since the theme of listening is so central to this novel, Shelley makes sure, by incorporating three different narratives, that readers get to hear all sides of the story . Walton's letters introduce and conclude the novel, reinforcing the theme of nurturing.