What is the theme in An Enemy of the People by Arthur Miller?

Hypocrisy is another theme in the book. When Dr. Stockmann first receives the lab report that the town's water is contaminated, the liberals who run the town's newspaper, "The People's Daily Messenger," are anxious to reprint the report so that the townspeople are immediately made aware of the toxic condition that exists in the town's water supply. The editor, Hovstad, and the assistant editor, Billing, are both proud progressives and boast about their liberal beliefs. However, as the story progresses and they learn more information about the water issue, they begin to abandon their philosophies and liberal convictions.