Arthur Miller's The Crucible takes place during the 1692 witch-hunt in Salem, Massachusetts. We become acquainted with the play's protagonist, John Proctor, during the first act and learn of his past. He isn't perfect, like many of the other good people in the play, but he is still a hero and a martyr for many people. Throughout the play Miller shows how the sacrifice of human life is permitted under the guise of law and order, through the significance of the title, debates over religion and parallels with McCarthyism.
In medieval times, alchemists used crucibles to separate gold from different metals. Miller's choice of The Crucible as the title of the play is symbolic. During the witch-hunt they succeed in extracting the "crÃÂ¨me de la crÃÂ¨me" of society but during the chaos of the trial, they end up destroying them. These people were not pure saints; they each had faults and weaknesses.
Take Giles Corey, for example, he was an ignorant and deaf old man
GILES [he cannot be crossed]: John Proctor, I have only last month collected four pound damages for you publicly sayin' I burned the roof off your house, and I -
PROCTOR [laughing]: I never said no such thing, but I've paid you for it, so I hope I can call you deaf without charge...
He may have been arrogant, but he still loved his family and kept them as his prime worry, even with his last breath. He sacrificed his life, so his boys could inherit his property, his dying words "More weight" as rocks crushed his fragile body.
John Proctor is a sinner; this is established in the commentary of the play in the first act.
...He is a sinner, a sinner not only against the moral fashion of the time,