In act 1, Reverend Hale arrives at Salem carrying a large stack of books. Hale is depicted as a naive intellectual, enthusiastic about finally getting the opportunity to consult his books and exercise his knowledge regarding the "invisible world." Reverend Hale is confident in his training and trusts that he will be able to identify witches and rid Salem of the Devil. When Mrs. Putnam inquires about his books, Reverend Hale confidently says,

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!

In act 2, Reverend Hale supports the Salem court and believes that he is still doing God's work by exposing witches. However, Hale begins to conduct investigations of his own and visits Proctor's home to question his Christian background. When Francis Nurse mentions that Rebecca has been charged with murder, Reverend Hale attempts to calm him and assures Francis that Rebecca has nothing to fear. Reverend Hale indicates that nobody is above suspicion and reveals his trust in Salem's court by saying,

Nurse, though our hearts break, we cannot flinch; these are new times, sir. There is a misty plot afoot so subtle we should be criminal to cling to old respects and ancient friendships. I have seen too many frightful proofs in court—the Devil is alive in Salem, and we dare not quail to follow wherever the accusing finger points!

In act 3, John Proctor, Mary Warren, Giles Corey, and Francis Nurse challenge Salem's court. During the proceedings, Reverend Hale begins to recognize that the court is corrupt and that the selfish officials are only concerned with exercising their authority and remaining in positions of power. When Elizabeth lies to protect her husband's reputation, Danforth has Proctor arrested, and Reverend Hale comes to his defense by saying,

Excellency, it is a natural lie to tell; I beg you, stop now before another is condemned! l may shut my conscience to it no more—private vengeance is working through this testimony! From the beginning this man has struck me true.

In act 4, Reverend Hale is overwhelmed with guilt and regret for his role in the witch trials. He begins visiting the prisons and encourages innocent Christians to offer false confessions in order to save their lives. When Danforth asks Hale why he returned to Salem, Hale responds by saying,

Why, it is all simple. I come to do the Devil’s work. I come to counsel Christians they should belie themselves. His sarcasm collapses. There is blood on my head! Can you not see the blood on my head!

When Reverend Hale first arrives in Salem, he is very confident in his education and ability to root out evil.  When Reverend Parris comments on the heaviness of Hale's books, Hale says, "They must be; they are weighted with authority."  He arrives with all his books and knowledge and believes that there is no way the Devil could hide from him.  Further, when Parris insists that his daughter's inability to listen to the Lord's name is a clear sign of witchcraft, Hale replies,

No, no.  Now let me instruct you.  We cannot look to superstition in this.  The Devil is precise; the marks of his presence are definite as stone, and I must tell you all that I shall not proceed unless you are prepared to believe me if I should find no bruise of hell upon her.

Again, Reverend Hale clearly sees himself as an expert in matters of witchcraft, even more so than another minister, and he explains that he will not take kindly to being doubted in his decisions.  In fact, he refuses to move forward in his investigation unless he can be guaranteed that his judgment will not be questioned.  

Further, in regard to those weighty books, Hale says,

Here is all the invisible world, caught, defined, and calculated.  In these books the Devil stands stripped of all his brute disguises. . . .   Have no fear now—we shall find him out if he has come among us, and I mean to crush him utterly if has shown his face!

Hale is unconcerned that the Devil might outsmart him and is entirely confident that he and his arsenal of knowledge will not only best the Devil, but also destroy him.  This is pride, indeed: interesting for a minister certainly.

At the end of act three, Hale has become convinced of the corruption in the Salem court. He leaves, shouting, "I denounce these proceedings, and I quit this court!" He then leaves the accused people of Salem to fend for themselves.  However, in the beginning of act four, Hale returns, singing a very different tune.  To Elizabeth Proctor, he now says,

Let you not mistake your duty as I mistook my own.  I came into this village like a bridegroom to his beloved, bearing gifts of high religion; the very crowns of holy law I brought, and what I touched with my bright confidence, it died; and where I turned the eye of my great faith, blood flowed up.

Hale now understands the pride with which he entered the town, and he knows that he is partially responsible for the course the accusations and trials have taken.  In fact, he tells Danforth, "There is blood on my head!  Can you not see the blood on my head!!"  He has returned to try to convince the convicted to lie and confess to witchcraft in order to save their own lives because he now believes that lying is better than giving up one's life for no other reason than one's pride.  He is clearly conflicted by his role, calling it "the Devil's work," but he is also trying to soothe his conscience and do right by these innocents, whom he left before at the court's mercy.

HALE: I must say it, Mr. Proctor; that is not for you to decide. The man's ordained, therefore the light of God is in him. 

The above quote is from Act 2.  Hale is doing an unofficial vetting of John and Elizabeth, because her name has been "somewhat mentioned" in the witchcraft proceedings.  Right before Hale's line, John Proctor admits that he sees no light of God in Reverend Parris.  He has a few reasons, and the reader tends to agree with John.  Hale's response is important because it shows him still fully supporting Parris and witchcraft trials.  That support for the court is further evidenced by the following quote:

HALE: Proctor, if she is innocent, the court—

Hale still firmly believes that the court system is incapable of mistakenly sentencing someone to death.  

By far my favorite quote from Hale is this quote:

"I come to do the Devil's work. I come to counsel Christians they should believe themselves."

He says the line in Act 4 before the very moving John Proctor "it is my name" sequence.  Hale has come back to Salem to convince John, Rebecca Nurse, and anybody else to lie and admit to witchcraft.  He wants them to confess, because it will save their lives.  That's a big shift for Hale, because it shows that he no longer trusts the courts.  He believes the courts are stealing God's most precious gift by sentencing innocent people to die.  

"Life, woman, life is God's most precious gift; no principle, however glorious, may justify the taking of it."