Mary Shelley's Frankenstein opens with Robert Walton, an ambitious explorer, finding and immediately bonding with an emaciated, frozen Victor Frankenstein. As Victor proceeds to tell his life story to Walton, we might assume that his first-person perspective will lead readers to empathize with him and take his side in the conflict between creator and creature. However, Victor's own account of his project to create life emphasizes his short-sighted and self-centered nature.
He mentions that he wants to create life so that
a new species would bless me as its creator and source; many happy and excellent natures would owe their being to me.
He wants to be treated as a god by his creations, and he wants to earn fame and notoriety in his field. He does not, however, consider how a sentient being will react to him—that it might not be grateful and that it might become resentful or destructive. Even worse, though, is that once Victor succeeds in bringing the creature to life, he immediately abandons it, disgusted by its appearance and in shock at what he has done. After Victor's brother is murdered by the creature (Victor is aware of the murderer's identity), Victor allows Justine to take the fall, even though she is completely innocent. He even claims to be suffering more than she is, since she is going to her execution with a clear conscience, while he is ridden with guilt.
Although Victor is not particularly sympathetic as a character in the early part of the novel, once the creature relays his own narrative, it is easy for the reader to empathize with the "monster." The creature recalls being brought to life by Victor, completely unaware of the world around him and overwhelmed by sensory overload. He seeks help from people who reject him for his hideous appearance. The creature poignantly recalls his time observing the DeLacey family and trying to approach their blind patriarch to win him over and join their community (since he cannot judge the creature based on looks).
When the creature is rejected by the DeLacey children, he feels that he has experienced enough pain, and although he is sensitive, articulate, and inherently good, the creature lashes out with violence. Having read Victor's account of his own creation, the creature knows that his maker abhors him, so the creature is utterly alone. Even his plea to Victor for a mate ultimately fails. Shelley's inclusion of the creature's perspective sways the reader to the creature's side, despite his violent and murderous acts. Hearing about his repeated experience of rejection despite his good nature, readers empathize with the creature's plight.