Primarily, Atticus is a hero because he acts according to his principles at great personal risk. Defending a black man accused of raping a white woman took a great deal of courage in the Jim Crow South, and Atticus chooses to do so because he believes it is right. He is willing to risk his standing in the town as well as, potentially, violent treatment to defend Tom Robinson. That he also manages to be a good father is also a measure of his heroism. Indeed, his decision to stand up to prejudice is an example to his children, who idololize him in return.