How does Harper Lee present good and bad in the society of Maycomb? Which techniques does she use?

One of the ways that Harper Lee shows the difference between good and bad is through her characters. Some characters seem good, but when faced with issues such as racism, they are bad. On the other hand, some people who might be considered bad are actually good. Then there are the characters who are either all good or all bad. For a character who seems good, but who is actually a hypocritical bigot, there's Miss Gates. Another character who is frowned upon by the community, but turns out to be a good person is Dolphus Raymond. And for the characters who are all good or all bad there's Atticus representing the good side and Bob Ewell representing the bad.

First, there's Miss Gates who seems good, but she's got a hypocritical heart. Gates is Scout's third grade teacher who, while discussing Hitler's discrimination and mistreatment of Jews in Germany in class one day, does not teach her students that there is a parallel problem with Whites mistreating African Americans in the South. She herself says a very racist thing while coming out of the courthouse after the Tom Robinson trial. Scout tells Jem what she heard Miss Gates say as follows:

"I heard her say it's time somebody taught 'em a lesson, they were gettin' way above themselves, an' the next thing they think they can do is marry us. Jem, how can you hate Hitler so bad an' then turn around and be ugly about folks right home--" (247).

This passage shows that a white teacher who is respected in the community can also be a hypocrite. She may seem like a great example for young people because she has a reputable job in the community, but her true racist colors are discovered by a clever little girl.

Next, there's Dolphus Raymond who has children with an African American woman, which is a big social no-no. He also walks around drunk all of the time, so the community sees that as strike two. Scout and Dill discover that Mr. Raymond isn't really drunk, but drinks cola wrapped in a brown paper bag to make people think he's drinking. When the kids ask him why he does that, he explains the following:

"I try to give 'em a reason, you see. It helps folks if they can latch onto a reason. When I come to town, which is seldom, if I weave a little and drink out of this sack, folks can say Dolphus Raymond's in the clutches of whiskey--that's why he won't change his ways. He can't help himself, that's why he lives the way he does" (200).

In a way, Mr. Raymond is a hypocrite, too, but he does it to protect himself and probably his mixed children from the full wrath and prejudices of the white community. 

Then there's Atticus who is the epitome of goodness, patience, kindness, and everything Bob Ewell is not! Bob Ewell, for example, pays for his alcohol with welfare checks and lets his children rummage in the dump for their dinner. Atticus is educated and fulfills his parental and community responsibilities by going to work each day, teaching his kids good values, and being a good example to the citizens of the county. Bob Ewell spits in Atticus's face, doesn't take care of his children like he should, and lives a selfish and disgusting life. For both of these men, what you see is what you get, basically. They are the same everywhere they go. In fact, Miss Maudie and Scout discuss this fact about Atticus as follows:

"'Atticus don't ever do anything to Jem and me in the house that he don't do in the yard. . .'

'Atticus Finch is the same in his house as he is on the public streets'" (46).

In a way, Bob Ewell is also the same at his home as he is in the streets--bad and mean. Atticus on the other hand is good and kind. Then with Mr. Raymond and Miss Gates, there are people who do the right things for the wrong reasons and those who to the wrong things for the right reasons. People are complicated and Harper Lee does a good job showing through her characters the many different levels of good and bad that we all might experience in life.