In chapter 3, after Scout has told Atticus about her difficult first day at school and her problems with the new teacher, Miss Caroline, Atticus reveals his best advice for understanding people.
You never really understand a person until you consider things from his point of view . . . until you climb into his skin and walk around in it.
This is advice that Atticus certainly lives by, and he strives to make his children understand it throughout the novel. There are many things that Scout is trying to understand—the new teacher, the hatefulness of the townspeople toward her father, Boo Radley, etc.
Harper Lee uses this idea to show Scout’s development at the end of the book. After Boo Radley has saved Jem and Scout, killing Bob Ewell in the process, Scout reconsiders her assessment of Boo. Previously, the kids had looked at him like a sort of secluded monster, to be feared. But in the last several pages, Scout says:
Atticus was right. One time he said you never really know a man until you stand in his shoes and walk around in them. Just standing on the Radley porch was enough.
Scout’s understanding of this advice demonstrates that she has grown, and that Atticus has been able to help her see that there is more to understanding people than just watching them and listening to them.
Chapter 3, an argument between Cal and Scout about Walter Cunningham: "There's some folks who don't eat like us...but you ain't called on to contradict 'em...Don't matter who they are, anybody sets foot in this house's yo' comp'ny, nd don't you let me catch you remarkin' on their wys like you was so high and mighty!"
Chapter 3, Atticus explaining that you have to look beyond a person and understand what they are going through..."You never really understand a person until you consider things from his point of view...until you climb into his skin and walk around in it." "Atticus and i had learned many things today, and Miss Caroline learned several things herself. She learned not to hand something to a Cunningham, for one thing, but if Walter and I had put ourselves in her shoes we'd have seen it was an honest mistake on her part. We could not hold her responsible when she knew no better"