The title of To Kill a Mockingbird has very little literal connection to the plot, but it carries a great deal of symbolic weight in the book. In this story of innocents destroyed by evil, the “mockingbird” comes to represent the idea of innocence. Thus, to kill a mockingbird is to destroy innocence. Throughout the book, a number of characters (Jem, Tom Robinson, Dill, Boo Radley) can be identified as mockingbirds—innocents who have been injured or destroyed through contact with evil. This connection between the novel’s title and its main theme is made explicit several times in the novel: after Tom Robinson is shot, Mr. Underwood compares his death to “the senseless slaughter of songbirds,” and at the end of the book Scout thinks that hurting Boo Radley would be like “shootin’ a mockingbird.” Most important, Miss Maudie explains to Scout: “Mockingbirds don’t do one thing but . . . sing their hearts out for us. That’s why it’s a sin to kill a mockingbird.” That Jem and Scout’s last name is Finch (another type of small bird) indicates that they are particularly vulnerable in the racist world of Maycomb, which often treats the fragile innocence of childhood harshly.
As the novel progresses, the children’s changing attitude toward Boo Radley is an important measurement of their development from innocence toward a grown-up moral perspective. At the beginning of the book, Boo is merely a source of childhood superstition. As he leaves Jem and Scout presents and mends Jem’s pants, he gradually becomes increasingly and intriguingly real to them. At the end of the novel, he becomes fully human to Scout, illustrating that…