Summary
After explaining how popular opinions might be false, Mill makes three further
arguments in favor of freedom of opinion.
His second argument (after the argument discussed last section that the popular
opinion could be false), is that even if the popular opinion is true, if it is
not debated it will become "dead dogma." If truth is simply held as a
prejudice, then people will not fully understand it, and will not understand how
to refute objections to it. Dissent, even if it is false, keeps alive the truth
against which it dissents.
Mill then turns to two potential criticisms of his argument.
First, one could say that people should be taught the grounds for their
opinions, and that having been taught these grounds, they do not then merely
hold prejudices but really understand the basis of their opinions. Mill replies
that in cases where differing opinions are possible, understanding the truth
requires dispelling arguments to the contrary. If a person cannot refute
objections, then he cannot properly be said to understand his own
opinion. Furthermore, he must hear these objections from people who actually
believe them, because it is only these people who can show the full force of the
arguments. Responding to objections is so important that if no dissenters
exist, it is necessary to imagine them, and to come up with the most persuasive
arguments that they could make.
A second criticism might be that it is not necessary for mankind in general to
be familiar with potential objections to their beliefs, but only for
philosophers or theologians to be thus aware. Mill replies that this objection
does not weaken his argument for free discussion, because dissenters still must
be given a voice with which to object to opinions. Furthermore, while in the
Catholic Church there is a clear distinction between common people and
intellectuals, in Protestant countries like England, every person is
considered responsible for his choices. Also, in modern times it is practically
impossible to keep writings that are accessible to the intellectuals from the
common people.
Mill then presents a third argument for the value of liberty of thought and
discussion. He writes that if a true opinion is not debated, the meaning of the
opinion itself may be lost. This can be seen in the history of ethical and
religious beliefs--when they stop being challenged, they lose their "living
power." Mill says that Christianity faces such a situation, where people's
beliefs are not reflected in their conduct. As a result, people do not truly
understand the doctrines they hold dear, and their misunderstanding leads to
serious mistakes.
