In To Kill a Mockingbird, Harper Lee uses gothic imagery to show that Boo Radley is an outsider, bird symbolism to show that both mockingbirds (innocent characters like Boo, Tom, and Dolphous) and blue jays (the Ewells) exist on the fringes of society, and she uses point of view to show that the narrator (Scout), the reader, and all visitors to Maycomb (Miss Caroline Fisher, Aunt Alexandra) are essentially alien to the small town political and social mores.
Through Scout's narration, Harper Lee shows that nearly all individuals who don't abide by conscience are outsiders in the novel:
They're certainly entitled to think that, and they're entitled to full respect for their opinions... but before I can live with other folks I've got to live with myself. The one thing that doesn't abide by majority rule is a person's conscience.
Here, Harper Lee shows that anyone ruled by "group think," "mob rule," and stereotypes is an illegitimate "insider" who make "outsiders" of those who are different: black (Tom), old (Mrs. Dubose), young (Scout), handicapped (Tom), reclusive (Boo), or learned and compassionate (Atticus).
Harper Lee juxtaposes the "outsiders" in Maycomb's society with the accepted "insiders" throughout the community to illustrate and compare their differences. Juxtaposition is a literary technique used when an author places two characters, ideas, or places side by side in order to develop comparisons and contrasts. Throughout the novel, Lee reveals how the "outsiders" in the community of Maycomb are treated in comparison to the "insiders." The "insiders" are community members who share the same prejudiced beliefs and values. They discriminate and persecute citizens with unique beliefs and situations known as "outsiders." Like Boo Radley, Tom Robinson, and Atticus, Dolphus Raymond reveals the stark contrast between the treatment of the "outsiders" and "insiders." Dolphus tells Scout and Dill,
"Some folks don't---like the way I live. Now I could say the hell with 'em, I don't care if they don't like it. I do say I don't care if they don't like it, right enough---but I don't say the hell with 'em, see?" (Lee 123).
Dolphus is an "outsider" because he interacts and lives with African Americans. The majority of Maycomb's white community views him with contempt for his taboo lifestyle, and he is discriminated against. Throughout the novel, Harper Lee uses juxtaposition to compare and contrast the lives of the "outsiders" to those of the "insiders."