caustic(Noun) Any substance or means which, applied to animal or other organic tissue, burns, corrodes, or destroys it by chemical action; an escharotic. caustic(Noun) The envelope of reflected or refracted rays of light for a given surface or object.
Answered by Aslan. As Atticus has explained to Scout many times about this, He is doing this becasue he values equailty and justice. He believes that everyone is equal and therefore just because Tom Robinson is black, doesn't mean that he should not defend him.e says to Scout many times, if he did not defend this man, he could never tell Jem or her (Scout) not to do something. He has to set a good example for his children and if he expects them to do something or follow certain values, then he must display them first.
Atticus made several specific points in his closing argument during the trial of Tom Robinson, but the most important was that the jury needed to disregard the fact that Tom was a black man and do their duty. Atticus reminded the jury to make their decision based on the facts and not from any racial bias.