What is a good introduction for The Crucible when you talk about the personal integrity?

In The Crucible, through the characterization of John Proctor, Arthur Miller conveys the idea that personal integrity and self-respect are far more important than reputation or even life itself.  An introduction to this subject might explore the high cost of relinquishing one's integrity: if an individual cannot feel good about his or her choices, it becomes terribly difficult for that person to think of him or herself as a good person, deserving of good things.  The idea of being comfortable with one's conscience, with being able to look oneself in the mirror and sleep peacefully at night, knowing that one has been honest, tried their hardest, and so forth, is essential to one's happiness and satisfaction with life.  Therefore, when Proctor feels that he has been dishonest and hurt his wife in the process, he feels incredibly guilty, as though he is a "fraud."  Regaining his sense of himself as a man of integrity, a man he can respect, becomes as integral to the play as his fight to save the lives of his wife and friends.