The discussions at the beginning of Act III show the bias of the court.
Martha Corey has been accused of reading material that would suggest she is a witch. (She is simply an avid reader.) This occurs at the beginning of Act III. She is being questioned by Hathorne and Danforth. Martha answers honestly and logically but Hathorne claims the court has evidence against her. When Giles screams that he has evidence that the accusations are false, he is removed from the court. Giles believes that Putnam's quest for land is his motive for adding to the accusations. This scene is significant because it shows the court's biased opinion. The court has heard evidence against Martha but will not hear Giles evidence that will condemn Putnam and the accusations against his wife.
The conversation continues. Francis Nurse accuses the girls of being frauds. Instead of hearing her evidence/argument, Hathorne claims it is contempt. When Proctor adds that Mary Warren has signed a deposition claiming the girls were lying, Danforth says he will not accept depositions. Danforth adds, "Do you know, Mr. Proctor, that the entire contention of the state in these trials is that the voice of Heaven is speaking through the children?" Again, this shows how biased Danforth and Hathorne are. They have made their minds up, much to the dismay of the evidence from Giles, Proctor, and others.