Atticus attempts to use Mrs. Dubose and her struggle with a morphine addiction to teach Jem a lesson about courage. She is an unlikely model of behavior given her treatment of Jem and Scout.
She regularly insults and harasses the children as they walk by.
When Jem feels that Mrs. Dubose has gone too far in her criticism of the Finch family, he retaliates by chopping off the heads of her flower bushes.
As punishment, Atticus assigns Jem to the duty that Mrs. Dubose suggests - two hours of reading aloud to her every day. Atticus insists that Jem go through with this punishment and later explains why.
As Jem reads, he and Scout witness the dying woman's battle against her morphine addiction and learn the true meaning of courage: "it's when you know you're licked before you begin but you see it through no matter what," Atticus tells them.
This quote is an elucidation of Mrs. Dubose' struggle and it applies also to the efforts Atticus makes surrounding the trial of Tom Robinson. In that case too, the outcome is clear before the outset. Atticus, nonetheless, persists in his defense of Tom Robinson, enacting the ethic he has pointed to in the example of Mrs. Dubose.
A number of the moral lessons presented in the novel are given direct statement, from lessons of empathy to lessons of looking past first impressions.
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