Atticus Finch is an archetype of personal courage in the novel, and his courage is demonstrated again and again. Atticus not only takes Tom Robinson's case, he defends Tom vigorously, pitting himself against the prevailing attitudes and customs of Maycomb. Atticus stands up to his neighbors' racism, knowing that in doing so, he is exposing himself and his family to difficult times. His moral courage is as strong as his physical courage, which is also demonstrated in the novel.
Atticus shows great physical courage when he positions himself between Tom Robinson and the lynch mob that has come for him. Sitting alone in front of the jail, Atticus waits for what he expects will happen. He is unarmed. The only time he shows fear occurs when the children suddenly show up and put themselves at risk. Atticus shows no fear for his own safety. With courage, he once again honors his moral principles, protecting Tom's life by risking his own.
Another display of Atticus' courage concerns his shooting of the rabid dog in front of the Radley house. Heck Tate turns to Atticus to kill the sick animal. Although he hasn't fired a gun in years. Atticus accepts the responsibility to bring the dog down in one shot, knowing that if he misses, disaster will result.
Throughout the novel, Atticus acts with courage in living up to his principles and in accepting moral responsibility.