Why does the creature become violent?

The creature’s violence is learned, and the book is explicit about the sequence. He begins with benevolence: he gathers wood for the De Laceys, longs to join them, and educates himself on purpose. Rejection — Felix’s blows, the rustic’s gun, Victor’s refusal of a companion — teaches him that kindness is not available to a body like his.

William’s murder is the turn from misery to policy. The creature discovers he can inflict on Victor the isolation he suffers, and he chooses that power. Shelley does not call this innocence. She does insist it is not an essence planted at the moment of animation. Nature-versus-nurture is the concept underneath the question: if readers skip the cottage chapters and start at the murders, they adopt the villagers’ verdict. The eloquent narrative exists so that verdict can be examined.