Reverend Hale responds to Proctor’s arrest by denouncing the proceedings.
Reverend Hale is from a nearby town. He comes to try to determine what is really happening. He is the investigator. Proctor is impressed by Hale, and expects Hale to bring common sense back to the community.
I’ve heard you to be a sensible man, Mr. Hale. I hope you’ll leave some of it in Salem. (Act 1)
Proctor assumes that Hale will not be as distracted by the hysteria as the rest of them. He is correct about this. Hale tries to get to the bottom of the supposed witchcraft. When Proctor gets arrested, Hale is frustrated and he says so.
Hale: I denounce these proceedings, I quit this court! He slams the door to the outside behind him. (Act 4)
This demonstrates that Hale has stopped humoring the people, and is no longer willing to just go along with it. He wants to let people know what he thinks, and he does not care what Danforth thinks about it.
This moment marks a turning point for the play. From this point on, things have become more serious. We see that things are getting out of control and becoming chaotic.