According to Atticus, a person's conscience should be immune to what other people think.
In chapter 11 of To Kill a Mocking Bird, Atticus is talking to Scout and she is asking him why he is defending Tom Robinson. Atticus answers that this case had to do with the "essence of a man's conscience." Then Scout replies that he must be wrong because most people seem to believe that he is wrong and they are right. Therefore, Atticus says that the "one thing that doesn’t abide by majority rule is a person’s conscience.”
