His job is to diagnose witchcraft if it is present and then provide a necessary cure
Attempts to discern evidence of witchcraft in Salem, Danforth and the court, try's to get the people to believe that its all fake.
He gets motivated because he was every one to know the truth. Wants to let them know that the girls are faking it all.
I have signed seventy-two death warrants. Who came to you with the devil. When the devil comes to you does he ever come, with another person.