The most important theme of To Kill a Mockingbird is the book’s exploration of the moral nature of human beings – that is, whether people are essentially good or essentially evil. The novel approaches this question by dramatizing Scout and Jem’s transition from a perspective of childhood innocence, in which they assume that people are good because they have never seen evil, to a more adult perspective, in which they have confronted evil and must incorporate it into their understanding of the world. As a result of this portrayal of the transition from innocence to experience, one of the book’s important sub-themes involves the threat that hatred, prejudice, and ignorance pose to the innocent people such as Tom Robinson and Boo Radley are not prepared for the evil that they encounter, and, as a result, they are destroyed. Even Jem is victimized to an extent by his discovery of the evil of racism during and after the trial. Whereas Scout is able to maintain her basic faith in human nature despite Tom’s conviction, Jem’s faith in justice and in humanity is badly damaged, and he retreats into a state of disillusionment.
The moral voice of To Kill a Mockingbird is embodied by Atticus Finch, who is virtually unique in the novel in that he has experienced and understood evil without loosing his faith in the human capacity for goodness. Atticus understands that, rather than being simply creatures of good or creatures of evil, most people have both good and bad qualities. The important thing is to appreciate the good qualities and understand the bad qualities by treating others with sympathy and trying to see life from their perspective. He tries to teach these ultimate moral lessons to Jem and Scout to show them that it is possible to live with conscience without losing hope or becoming cynical. In this way, Atticus is able to admire Mrs. Dubose’s courage even while deploring her racism. Scout progress as a character in the novel i...