When Jem gets angry at Mrs. Dubose, an unpleasant neighbor who insults his father for defending Tom Robinson in court, he decimates her flowers and plants with Scout's baton in revenge. When Atticus learns what Jem has done, he says to his son,

"I have no doubt that you've been annoyed by your contemporaries about me lawing for niggers, as you say, but to do something like this to a sick old lady is inexcusable. I strongly advise you to go down and have a talk with Mrs. Dubose."

Mrs. Dubose has reprehensible opinions about a lot of things—opinions with which Atticus very much disagrees. However, just because Mrs. Dubose has lashed out at him and his children does not, in his mind, give him or the children the right to retaliate against her. Atticus seems to believe that it says more about Jem if he is willing to ruin a sick old lady's flowers—as terrible as she may be—than about the sick old lady who did the insulting herself. He compels Jem to go and read to Mrs. Dubose almost every day for a month to make up for what he did. He compels Jem to sow kindness when he'd been treated disrespectfully because it says more about the person who does the disrespecting than it does about the person who is disrespected.

In Chapter 3, Jem invites Walter Cunningham Jr. over to their house for dinner. While Water is eating, he begins to pour syrup all over his meat and vegetables. Scout is appalled and asks "what the sam hill is he doing." (Lee 32) Walter is embarrassed, and he quickly puts the saucer down and bows his head. Atticus looks at Scout and shakes his head. Scout begins to protest again and tries to explain that he's "drowned" his dinner in syrup. Calpurnia tells Scout to follow her into the kitchen and proceeds to yell at Scout for her rude comments. Cal explains to Scout that Walter is their company, and she needs to treat him with respect, regardless of how he chooses to eat. Scout argues that Walter is not their guest because "he's just a Cunningham." Calpurnia says,

"Hush your mouth! Don't matter who they are, anybody sets foot in this house' yo' comp'ny, and don't you let me catch you remarkin' on their ways like you was so high and mighty! Yo' folks might be better'n the Cunninghams but it don't count for nothin' the way you're disgracin' 'em---if you can't act fit to eat at the table you can just set here and eat in the kitchen!" (Lee 33)

Calpurnia teaches Scout that her manners are a reflection of her character after Scout judges Walter Cunningham Jr. for his eating habits. When Cal says, "it don't count for nothin' the way you're disgracin' 'em," she means that Scout's family reputation is useless when she disgraces other people by judging them. Scout learns that judging Walter says more about her rude manners than it does about Walter's eating habits.