Where do the characters show wisdom?

To Kill A Mockingbird is a great story where the principal characters often show great wisdom.

One of the most memorable lines in the novel comes from Atticus:

The one place where a man ought to get a square deal is in a courtroom, be he any color of the rainbow, but people have a way of carrying their resentments right into a jury box. As you grow older, you’ll see white men cheat black men every day of your life, but let me tell you something and don’t you forget it— whenever a white man does that to a black man, no matter who he is, how rich he is, or how fine a family he comes from, that white man is trash.

Atticus stands ready to defend Tom Robinson even though he knows that his decision will never win the support of the Maycomb populace. Nevertheless, his unswerving faithfulness to his conscience crowns his actions with dignity and wisdom. He is single-minded in the face of public displeasure. Because of his words of wisdom, Scout later arrives at her own wisdom regarding Boo Radley:

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.

After Boo Radley saves Jem from Bob Ewell, Scout comes to realize that she has unfairly judged her shy neighbor. Boo Radley has always been in the background, retiring and mysterious, but when it counts the most, he is there for both Jem and Scout. Like her father, Scout has learned the wisdom of understanding and self-awareness. Her new-found wisdom allows her to leave her fears behind and to walk Boo Radley home with grace and acceptance after Boo visits with Jem.

Jem, young as he is, also demonstrates wisdom in the story. Although often brash and mercurial as only a big brother can be, he displays surprising tenderness towards his sister after the Maycomb jail episode. When men come ready to lynch Tom Robinson, Jem resolutely stands beside his father and refuses to go home. He disobeys Atticus' direct order and remains faithfully by his side. Even though it is Scout who ultimately defuses the situation with her innocent banter, it is Jem who comforts her when she later realizes the full impact of the evening's tension-laden drama.

Jem took me to his room and put me in bed beside him. "Try to go to sleep," he said, "It'll be all over after tomorrow, maybe."

The full meaning of the night's events hit me and I began crying. Jem was awfully nice about it: for once, he didn't remind me that people nearly nine years old didn't do things like that.

Jem exhibits great wisdom in staying with his father during the jail incident; instinctively, he knows that his neighbors would never attack Atticus in the presence of his children. His subsequent tenderness towards his frightened and traumatized sister shows that he has taken Atticus' advice to heart; his sympathetic attitude towards Scout shows that he is capable of understanding others by examining matters from their perspective.