A theme is a broad idea, moral or message of a book or story. What hooks you? Miller wrote about the event as a parable for McCarthyism and the Red Scare; which occurred in the United States in the 's. Hale has complete trust in John Proctor's claim of adultery and begs the court to stop the murders of all these innocent people.
The play was originally produced in at a time where McCarthyism was at its peak. In fact, the title of the book itself has at least 6 different meanings. I see no light of God in that man.
This was a time of American paranoia when Americans believed that the Russians were planning start a war with them.
Those who lack authority also lack innocence.