The multiple narrations in Frankenstein allow the story to be passed on, like the light of knowledge, the dominant motif in the novel.
Here's how the POV breaks down:
- Walton frames the novel by writing to his sister (and us, the readers) about Victor.
- In Walton's frame, Victor tells Walton (and us) about the Monster.
- In Victor's frame, the Monster tells Victor (and us) his feelings.
- In the end, Walton is left to carry the tale (the light of knowledge) back to the community of mankind
- If we didn't have Walton, the story would never reach us. Who will deliver his letters to his sister? (Victor and the Monster essentially die chasing each other on the ice)
The embedded narrative style is the only way to get to the Monster and let the Monster speak for himself. In this way, every major character has a kind of first-person point-of-view. In this way, the audience gets all sides of the story to determine how knowledge should be handled.
The multiple perspectives also determine the fate of Walton, who is most like the reader and a foil for Victor. All the while, we are wondering if Walton will turn back in his quest for the pole. Instead, Victor's morality tale causes him to return to the community of man. Does it do the same for us? (With the advent of human cloning, I wonder)...
In the book Frankenstein the author is trying to present the picture from different points of view. By carefully setting up the story so that it shifts from person to person, it allows the reader to follow Victor's thoughts so one can see why he made the decision to create the creature, abandon the creature, his shame, his ambition from his own perspective.
The creature is given a voice by having him narrate his side of the story. This enables the readers to develop a sense of empathy for the creature. One learns to see his pain and suffering. He is a dynamic creature.
The captain is the neutral party who can look at both sides and weigh in on the issues as an outsider looking inward. It is through him that the reader is allowed to agree that Victor has treated the creature cruelly.