Many people advocate freedom of speech, thinking that freedom of speech can solve the problem of freedom of thought. In fact, freedom of expression does not necessarily lead to freedom of thought. If we observe some expressions on the Internet media, we will find that there is a kind of trend, rigorous people may not necessarily participate in expression and discussion, and there are many irrational cases of abuse and malicious attacks on the coal body of the Internet. As a result, although free speech, one's thought expression is easily vulnerable to siege This is not freedom of thought, it's just freedom of speech. What does this passage mean? ['The premise of freedom of thought is not freedom of expression.', 'Free speech will lead to extremes of thought.', 'Freedom of thought is not equal to freedom of speech.', 'Freedom of speech does not necessarily lead to freedom of thought.']