In Harper Lee's 1960 Pulitzer Prize winning To Kill a Mockingbird, Boo Radley at first seems to be a small character, however Jem, Scout and Dill all want to see him. He is veiled in secrecy. All of three of the children try to get Boo to come out. They use their own imaginations to form an opinion about Boo. The whole book itself is about racial injustice and prejudice. As you can see Harper Lee wanted the reader to get a taste of it from the children's point of view first by adding Boo to the mix.
Boo is the one who saves Jem and Scout. When Atticus tells Jem "I'd rather you shot at tin cans in the backyard, but I know you'll go after birds. Shoot all the blue jays you want, if you can hit them, but remember it's a sin to kill a mockingbird" and when Jem says that it was the first time he had heard his father ever say anything was a sin and asked about it he was told "Mockingbirds don't do one thing but make music for us to enjoy. They don't eat up people's gardens, don't nest in corncribs, they don't do one thing but sing their hearts out for us. That's why it's a sin to kill a mockingbird" are two of the greatest lines in the book. Both of these lines tell you about a person not just a bird. After Boo saves them, Scout tells her father that if the police knew what really had happened when Boo saved them, it would be like killing a mockingbird. The reality of who Boo really was turned out to be far greater than their imaginations could ever have come up with.
In Harper Lee’s To Kill a Mockingbird, the next door neighbor Radleys form an important subplot. The secretive and mysterious Boo Radley captures the imaginations of Scout, Dill, and Jem in a profound way. Since they never actually see Boo, they imagine all sorts of terrible things about him. They believe he has a terrifying appearance, a penchant for eating cats, and a violent nature.
Part of Lee’s purpose with this subplot is to give emphasis to the powerful imaginations of youngsters. All three of them attempt to lure Boo out of his house. These escapades are amusing and create a minor series of conflicts with their father, Atticus Finch, who implores the kids to leave Boo alone. But they have begun to believe their own fantasies.
Ironically, it is Boo who saves the lives of Scout and Jem at the end of the story. The kids learn that the real danger in their lives isn’t their shy neighbor, it’s the hatred and ignorance represented by Bob Ewell, who is killed by Boo when he attacks the kids in a nearby wooded area. By the time the novel ends, the kids have learned that there are real monsters in the world apart from the monsters they have created in their own minds. On the last half page of the book, the narrator, Scout Finch is speaking to Atticus about Boo when she says,
An’ they chased him ‘n’ never could catch him ‘cause they didn’t know what he looked like, and Atticus, when they finally saw him, why he hadn’t done any of those things . . . Atticus, he was real nice . . .
To which Atticus responds,
Most people are Scout, when you finally see them.