The last sentence of Chapter 9 underscores the themes contained in "To Kill a Mockingbird": Prejudice and Acceptance, Loss of Innocence, Courage and Cowardice, Knowledge and Ignorance. Scout has learned several lessons in this chapter which has "social realism" as its theme. She finds herself at ends with the meaning of education; school is not worth much to her and she has difficulty getting along with school mates, she does not comply as her aunt and uncle try to educate her in the social code of a young lady, and she argues with her cousin Francis, defending herself while Francis weakly calls on his grandmother for aid.
From listening to Atticus, ahe learns that Uncle Jack displays loyalty for the family; also, she learns that although in her society Tom Robinson is already judged' her courageous father is going to defend him because he must defend truth. Atticus realizes that he must set an example for his children, stating that he cannot face his children if he does not stand up for truth and hopes the children will come to him for knowledge on the case after the trial. So, the problems that Atticus encounters are much like those of his small daughter. From Atticus Scout learns to be courageous and defend the truth, she loses some of her innocence as she learns of the town's prejudices, and she understands that she must be more tolerant of others.