Have you read George Orwell's novell, 1984? If you haven't, I'd highly recommend it. I think you would really enjoy it as the entire book revolves around people who have been enslaved mentally. In fact, a famous quote from the book is: "Freedom is the freedom to say that two plus two make four. If that is granted, all else follows." I think this is in reference to people's freedom of speech being stifled by fear, which is a powerful motivator. Political correctness is a term we have today for "agreeable" type speech that often intentionally avoids being truthful or direct out of fear of offending someone.