This occurs in Act III. Hale asked Parris if every defense that occurs has to be an attack on the court. Hale seemed to have a sarcastic tone in asking this question.
Parris responds with the words:
All innocent and Christian people are happy for the courts in Salem!
This is ironic because Rebecca Nurse and John Proctor are two of a faction of people who are not happy with the courts. In fact, they are distraught at the thought of what the courts are doing by accusing innocent people of witchcraft.
The reason this incident is significant is because it shows that Hale is beginning to question the authority and purpose of the court and that Parris is further being dragged into the lies of the court.
When Hale, Danforth, and Parris hold this discussion in Act III, they are being approached by Proctor who bears a petition testifying to the good opinion of the people of Salem regarding Rebecca, Martha Corey and Elizabeth Proctor.
Parris reacts to Proctor's efforts to clear the names of the innocent women by claiming it is "a clear attack on the court!" This is when Hale speaks up as a voice of reason.
Hale: Is every defense an attack upon the court? Can no one -?
Parris: All innocent and Christian people are happy for the courts in Salem! These people are gloomy for it. To Danforth directly: And I think you will want to know, from each and every one of them, what discontents them with you!
Several layers of meaning are present in this moment, creating the irony asked about here.
- The audience is well-aware that Elizabeth and the other women are innocent of witchcraft and have been accused as the result of nefarious motives.
- Also, Parris himself instituted the witch-hunts as a way to deflect blame from his own family because his daughter actually was practicing witch-craft (or voodoo) with Tituba in the woods.
- Finally, the petition brought by Proctor is intended to communicate the idea of innocence for the women being discussed but Parris makes an opportunity out of it to investigate those who signed their names to the paper. Instead of clearing the names of three women, the petition will potentially endanger the lives and reputations of the 91 people who signed it.
The audience knows that the innocent should indeed be afraid of the court because the court is being run in part by Parris, a man thoroughly compromised morally and willing to perpetuate a deadly fraud on Salem, and Danforth, a man who shows no compunction about sentencing people to death based on hearsay and questionable witness testimony.
Thus the irony of Parris response to Hale is that (1) Parris himself is not innocent yet he is the one who has nothing to fear from the court and (2) a statement of innocence has now become a tool of accusation against all who signed it.