What is Mary Warren's motive for accusing John Proctor of doing the Devil's work?
Abigail wants Elizabeth dead so she can resume her affair with Proctor. Does Mary Warren have a reason for wanting either John or Goody Proctor dead?
Mary is motivated by Abigail. Abigail threatens the girls if they do not follow through with her malicious scheme. Mary is caught up in play acting. She is motivated by all the attention that she and the girls are receiving:
Mary Warren is the Proctors' servant who seems timid and subservient but who finds a powerful role in a kind of people's jury in the courtroom.
In her refusal to cooperate with John Proctor, Mary seems to be stubborn and rebellious when she insists that she attend the hearings of the court. Mary is bent on attending even at John Proctor's forbidding:
She occasionally dares to defy Proctor, particularly in her insistence that she must attend the hearings
After John Proctor convinces her that she must testify against Abigail in court, Mary does seem to have a conscience and determines to do the right thing. However, Abigail's presence is threatening and Mary soon changes her mind:
She becomes hysterical before the court, however, and soon joins Abigail in pretending that mere is evil witchcraft at work. Her behavior in the court contributes, in part, to John Proctor's arrest.
Mary acts out of fear for her own safety. She does not want to be determined as one who has been pretending. She fears the court and what the court could do to her. She also fears Abigail. She also enjoys the power she has at the hearings.