To Kill A Mockingbird deals with racial prejudice of the worst kind when Tom Robinson is accused and found guilty of a crime based solely on his race and the propensity of the Maycomb County Community to believe that Tom must have committed this crime simply because he is a black man. The facts are immaterial; the evidence against Mayella's own father is not a consideration and the hypocritical and unchristian-like attitude of the community is not even recognized.
As a single father, Atticus has always tried to teach his children to appreciate the viewpoint of "all kinds of folks." He wants his children to recognize the perspective of other people so as not to judge them too harshly or unfavorably because, as he points out to Scout, you need to "climb into his skin and walk around in it" to gain a real understanding of another person. The same goes for any derogatory comment. It is empty and inappropriate and does not lead to a better understanding of the person being called that name. "It don't mean anything...(it is) a common, ugly term to label somebody."
Atticus does not want Scout to use the word because it is "common" and serves no purpose, much like pre-judging people. A comment, therefore, tells you more about the person making it than it does about the person against whom the comment is directed. This is especially relevant as even family members such as Scout's cousin Francis use it to shock and embarrass Scout. Even without knowing what it means, Scout can tell from the tone that it is intended to be insulting.
Atticus thinks it is more important to concentrate on doing the right thing, in this instance defending Tom Robinson, than to allow "Maycomb's usual disease" to influence his decisions or affect his children.
Atticus forbids Scout from using the "N" word because it is "common," but he does admit to being a "nigger-lover."
"I certainly am. I do my best to love everybody." (Chapter 11)
Atticus begs Scout not to lose her temper when her friends insult her father because of his defense of Tom Robinson. He tells her that it is only "one of those terms that don't mean anything--like snot-nose." Atticus believes that only "ignorant, trashy people" use the term, though he admits that "some people like ourselves" occasionally fall back on it as an "ugly" way to exert their racial prejudice. Atticus despises white people who will deliberately cheat a black man, calling it "the worse thing you can do." Atticus also complains to his brother Jack about how
"... reasonable people go stark raving mad when anything involving a Negro comes up, is something I don't pretend to understand." (Chapter 9)
Atticus lives his life according to a higher code than anyone else, it seems. He is not bothered by people calling him prejudiced names because he knows that by defending Tom Robinson, he is doing what is right. Atticus would rather live by his moral code and be able to face himself each morning in the mirror than cower before a few people who call him names. The only thing that truly bothers him is when people call him names to his children. Even then, Atticus's moral code is to do nothing about it. He still considers people who call him bad words his neighbors and friends. He's just that good of a person and completely non-confrontational. The best advice that Atticus gives regarding the N-word is the following:
". . . baby, it's never an insult to be called what somebody thinks is a bad name. It just shows you how poor that person is, it doesn't hurt you" (108).
This passage shows that Atticus doesn't let verbal sticks and stones hurt him. He stays in control of his life and his emotions. He never gives anyone power over his feelings simply by calling his insulting names.