What does Atticus tell Scout to do when she hears "ugly talk" at school?

When Cecil Jacobs calls Atticus a "nigger-lover", Scout is all too quick to defend her father--by using her fists and beating Cecil into the ground. When Atticus hears about this, he does not scold Scout (in typical Atticus fasion). Instead, he tells Scout that she's probably going to hear some ugly talk at school during the trial. He requests that she keep her head held high and to not use her fists to solve her problems. She does very well with this request until Christmas, when she strikes her cousin Francis for insulting Atticus.