Throughout On Liberty, Mill discusses the importance of human liberties, freedoms and opinions. The quote below is from the first half of On Liberty and summarizes the main theme:
But the peculiar evil of silencing the expression of an opinion is that it is robbing the human race; posterity as well as the existing generation; those who dissent from the opinion, still more than those who whold it. If the opinion is right, they are deprived of the opportunity of exchanging error for truth, if wrong, they lose, what is almost as great a benefit, the clearer perception and livelier impression of truth, produced by its collusion with error. (Mill)
Mill talks about how it is evil, or wrong, to silence the expression of an opinion and that it robs the human race. Silencing the expression of an opinion is the government or society not allowing an opinion to be expressed either because of laws that prohibit it or through the threat of punishment. Mill talks about government tyranny and how the government should not be allowed to control individuals on matters that concern themselves, unless someone expressing his or her opinions will cause harm. Mill states that it is wrong to prevent or prohibit someone from being able to express him or herself because it robs the human race from getting an opportunity. People gain an opportunity to learn and grow when they hear the opinions, thoughts, and beliefs of others. Mill believes there is much to gain from individuals’ opinions or to say the same; there is much to lose by not hearing those opinions. If no one heard other people’s opinions then everyone would belief their own as all truth, so hearing others’ opinions and thoughts allows for people to think and learn actual truths. Mill talks about three parts to liberty that individuals should have reign over in their own lives which are the freedom of thought and opinion, liberty or freedom to pursue what one wishes for their life, and to