Hale already has reservations about the witch craft trials by the time that Act 3 starts. In Act 2, Hale went to visit the Proctor household and admitted that he was a little astounded at the number of accused. He was also astounded at the women that were now being accused of witchcraft as well. People like Rebecca Nurse were famous in the Puritan community for being good and wholesome.
By the end of Act 3, Hale completely changes his opinion on the court proceedings. He no longer believes that Abigail Williams is a trustworthy source. He believes John Proctor is correct that Abigail is out for blood, because Hale sees that John is willing to throw away his good name in order to defend his wife. Hale finally realizes that he was overzealous in his pursuit of witches, and he sees that innocent people are going to die.
"I denounce these proceedings! I quit this court!"
By Act 4, Hale has come so far as to try and convince the accused to lie under oath in order to save their lives.
"Why, it is all simple. I come to do the Devil‘s work. I come to counsel Christians they should belie themselves."