Here is all the invisible world, caught, defined, and calculated. In these books the Devil stands stripped of all his brute disguises. Here are all your familiar spirits – your incubi and succubi; your witches that go by land, by air, and by sea; your wizards of the night and of the day. Have no fear now – we shall find him out if he has come among us, and I mean to crush him utterly if he has shown his face!
The arrival of Rev. Hale to the Parris home towards the end of Act 1 reveals him to be a smug, if intelligent, man who calmly explains to the residents of Salem that he can easily identify a witch. His self-assurance will soon crumble, but here Hale represents a warning that some things are less clear than they may initially seem, and that even very smart people can be wrong.
I come to do the Devil’s work. I come to counsel Christians they should belie themselves. There is blood on my head! Can you not see the blood on my head!!
By Act 4, Rev. Hale is a changed man. He’s no longer certain of anything, except the fact that the Salem witch trials have condemned and killed innocent people with his help. He tells Danforth that he is trying to get the innocent prisoners to confess to witchcraft in hopes of saving their lives, his duty for helping to condemn them.
Life, woman, life is God’s most precious gift; no principle, however glorious, may justify the taking of it. I beg you, woman, prevail upon your husband to confess. Let him give his lie. Quail not before God’s judgment in this, for it may well be God damns a liar less than he that throws his life away for pride. Will you plead with him? I cannot think he will listen to another.
In Act 4, Rev. Hale pleads with Elizabeth to try to get John to confess to witchcraft, which would save his life. Hale has arguably gone through the most drastic change over the course of the play. Once a smug young pastor who thought he understood morality, he is now reduced to begging people to lie to save themselves.