What role does Boo (Arthur Radley) play in To Kill a Mockingbird and how does he affect the story?
Arthur (Boo) Radley is a central symbolic figure in Harper Lee's To Kill a Mockingbird. He represents mockingbirds, actually, because he never makes trouble for anyone; he never hurts anyone; and, he minds his own business--unlike many others in Maycomb. Atticus tells his children that it is a sin to kill mockingbirds, so if Boo is like a mockingbird, he is peaceful, yet vulnerable, to social predators. The way people treat Boo Radley helps to determine their own quality of character. For example, Miss Stephanie Crawford uses information on Boo Radley's past to spread rumors and make herself feel important. As a result, she adds rumors that he looks into people's windows at night, which hurts his reputation.
Boo Radley affects the story at the beginning because he is mysterious and spooky for Scout, Jem, and Dill. For two summers, the children's games and behavior are influenced by him and the mystery surrounding his life. When Boo makes an effort to befriend the children by placing gifts in the knothole of his oak tree, Jem and Scout slowly learn that people aren't what rumors make them out to be. He also gives Scout a warm blanket on the cold night of Miss Maudie's house fire, which is not the behavior of a bad man.
In the end, the ironic twist is that Boo Radley saves the children's lives from a deadly attack by Bob Ewell. The mysterious man of Maycomb is actually a hero and friend rather than a spooky boogieman. Without Boo Radley in the story, there wouldn't be a strong symbolic figure for the children to learn tolerance from. Sure, Tom Robinson also represents a mockingbird, but Boo Radley is closer to the children in proximity and lifestyle because he is a neighbor. Boo Radley's life and presence in the story also add a special type of mystery and suspense for the reader, so that by the time he saves the children in the end, the surprise is comforting and welcome.