How does Atticus explain understanding another person's actions in To Kill a Mockingbird?
Atticus' explanation to Scout concerning the need to respect other people's opinions and actions illustrates this best.
"... if you can learn a simple trick, Scout, you'll get along a lot better with all kinds of folks. 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."
It is a philosophically positive and progressive point of view, especially in the ultra-conservative world of 1930s Maycomb, where racism and intolerance are the norm. Atticus believes that all people are equal, and that their opinions should be valued and respected--even Bob Ewell's. After Bob spits in Atticus' face and threatens him, Atticus suggests that Jem
"... stand in Bob Ewell's shoes a minute. I destroyed his last shred of credibility at that trial... The man had to have some sort of a comeback... he had to take it out on somebody."
In the final paragraphs of the novel, Scout recognizes that one of the characters in the book Atticus had been reading to her, Stoner's Boy, was actually "real nice," although he had been accused of things he had not done--just like Boo Radley. In typically hopeful Atticus fashion, he tells her that
"Most people are, Scout, when you finally see them."