One of the more admirable qualities of Atticus Finch is his ability to consider the perspectives of others. He is also quite conscientious and considerate. He thinks of how each person thinks about the world and how his own interactions with that person might affect others. In short, he has a keen and compassionate understanding of each individual in Maycomb and how his own actions contribute to the social dynamics (interactions) among the other citizens. Therefore, Atticus is thoughtful and careful about what he says and does.
Here is an example. At the beginning of Chapter 23, we learn that Bob Ewell has spit in Atticus' face. The trial is over and Atticus lost, but Bob was embarrassed in the courtroom and he continues to hold a grudge against Atticus. Bob spits in his face but Atticus does not retaliate. When Jem asks him why, Atticus tells him that he felt it was necessary to allow Bob to take his anger out on him:
Jem, see if you can stand in Bob Ewell’s shoes a minute. I destroyed his last shred of credibility at that trial, if he had any to begin with. The man had to have some kind of comeback, his kind always does. So if spitting in my face and threatening me saved Mayella Ewell one extra beating, that’s something I’ll gladly take. He had to take it out on somebody and I’d rather it be me than that houseful of children out there.
Even after losing the trial and dealing with Bob's and Mayella's lies, Atticus still looks at Mayella as a victim. He knows she is partly responsible for Tom's conviction. But Atticus knows that Mayella has been a victim in the Ewell family since she was born. Her father is physically and verbally abusive. And with no mother, Mayella has had to take over that role. Atticus considers all of this after he's been spit upon.