How is Atticus’s sense of justice inferred when he tells the children they can shoot all the bluejays they want, but “it is a sin to kill a mockingbird”?

While To Kill a Mockingbird by Harper Lee is not a particularly symbolic novel, the mockingbird is an inescapable symbol which both Miss Maudie and Atticus try to help Scout understand. After Atticus makes his statement about killing bluejays (or other birds) but never killing mockingbirds, Scout feels the need to question her father's edict, mostly because it is so unusual. She asks Miss Maudie about Atticus's perplexing statement, and she gets an answer she can begin to understand. So, a literal mockingbird is a creature who sings beautiful music for the benefit of others and never does harm to anyone. A figurative mockingbird is someone who is innocent, who does kind things for others without asking for anything in return. Those kinds of people, according to Atticus, deserve to be protected. Anyone who tries to hurt them is committing a sin, because these kind-hearted people have done nothing but make the world a better place for those around them.

Explanation:

In this novel, two characters could be considered mockingbirds, and Harper Lee makes sure we make the connection. The first is Tom Robinson, a man who did nothing to deserve trouble except try to help a young girl who seemed desperately lonely and seemed to need his help. In exchange for that innocent act of kindness, he is accused of rap3 and will eventually pay the highest price for that kind deed. This is why Atticus defends Tom. Mr. Underwood, who has no real love for the black people in town, describes Tom's death as being similar to “the senseless slaughter of songbirds by hunters and children.” This is a clear argument that he is an innocent who did not deserve to die.