Hale is humbled. The most signficant change in his character relates to this humbling, as Reverend Hale learns that his over-confidence and pride lead to the deaths of innocent people.
As the play opens, Hale's pride is flattered by Parris and others. Though he tries to be exacting and academic in his approach to the question of witchcraft in Salem, Hale is ultimately swept up by the notion that his intuition is correct and witchcraft is indeed afoot in Salem.
In the face of persuasive opinions offered by John and Elizabeth Proctor, Hale maintains his self-assurance, choosing to refrain from questioning his assumptions and instead watching while Elizabeth is taken to jail.
Hale is finally convinced of fraudulent nature of the witchcraft accusations when Proctor brings Mary Warren to court and then Proctor testifies to his affair with Abigail. At this point, Hale is shocked and dismayed. He realizes what his pride has helped bring into being in these trials. He realizes that he will be responsible if Elizabeth is killed.
Hale's transformation into humility is seen clearly in his demeanor in the final act of the play. Here Hale is seen pleading with Danforth, and pleading with Proctor too, trying to avoid becoming guilty and complicit in Protor's death by hanging.
From pride and self-assurance, Hale falls into desperation and humility.
Rev. Hale is summoned from Beverly to Salem at the request of Paris and Putnam (two noteworthy villians in the text). He brings "heavy books" he says are "weighted with authority" to identify and cast out devils, witches, etc. from "afflicted" persons. In other words he comes with an ego (pride) and is supposed to find "signs of witchcraft" in the girls. Keep in mind that the girls themselves have practiced black arts with Tituba. Rebecca Nurse, by contrast, indicates a "prodigious danger in seeking loose spirits." She "fears it."
He is a "young" man with "old school" Puritan values. He says, "You know that Satan cannot overcome a minister" and later indicates that because Rev. Paris is "ordained" it follows that the "light of God" is in the man despite an outward reputation that would suggest otherwise.
He is "with the court" for much of the play--later signing "17 death warrants." He allows himself to be swayed by public pressures and especially the pressures of the judges. When R. Nurse and others are later jailed, Proctor calls him "Pontius Pilate" and "a broken minister."
Later we see him begging innocent people to confess to lies to save their own lives. (Keep in mind that telling a lie is a sin!) This causes Eliz. Proctor to wonder if he is using "the devil's argument" to entrap sinners. This irony should not be lost on readers.
By the end, we like him slightly more than in the beginning--because he opposses Paris--and because we think he sort of knows that the claims of witchcraft were false. This doesn't save any lives though.
Overall, he represents rigidity, religious intolerance, and ignorance--killers when mixed with hubris!
*Quoted lines from The Crucible by A. Miller