What is the thematic concept of the novel based on Atticus' closing argument in To Kill a Mockingbird?

Harper Lee touches on most of her main themes of
To Kill a Mockingbird during Atticus' highly dramatic and moving
summation to the jury at the end of the Tom Robinson trial. Among them
are

• Prejudice and
  Intolerance.  Atticus begs the jury to disregard Tom's color and make
  their decision from the facts
  presented.


• Guilt and
  Innocence.  Atticus has seemingly proven his case, showing that Tom could
  not have committed the crimes of which he is charged. Instead of Tom, Atticus says,
  someone else present in the courtroom (either Mayella and/or Bob Ewell) is the guilty
  party.


• Courage and
  Cowardice.  Atticus shows courage taking the case, and he makes it clear
  that Bob Ewell and his daughter are the true cowards
  here.


• Knowledge and
  Ignorance.  Atticus has presented his case, and he hopes that the jury
  will use this knowledge to bring back a fair verdict. He is aware, however, that many of
  the jurors will turn a deaf ear to the testimony, and revert to the ignorant viewpoint
  that a white man's word always supercedes the word of a black
  man.

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