Mill on Liberty of Expression

There are two things about Mill’s life that it helps to know about when reading On Liberty. The first is that his father, James Mill, and Jeremy Bentham were staunch advocates for enabling more people to vote. John Stuart Mill was not opposed to that. But he was rather worried about the dangers of an intolerant, closed-minded public taking charge.

The second fact is that Mill had an unusual and long-standing relationship with a woman named Harriet Taylor. Harriet Taylor was inconveniently married to John Taylor at the time. Mill was a public figure and I have no doubt that he was highly self-conscious about this. Make of it what you will.

Utilitarianism and Liberty

Mill’s utilitarian case for liberty rests on two propositions:

  1. Liberty is beneficial to the individual.
  2. Liberty is beneficial to society.

While Mill’s case is complex, there are some common themes.

In making the case for the benefits of individual liberty, Mill repeatedly asserts that individuals have to make opinions and ways of living their own and that they can do that only if they are at liberty to make up their own minds or choose their own way of life.

In addition, many of his arguments apply even to cases in which individuals do not make good decisions. In these cases, Mill tries to show that the alternatives to individual liberty would generally be worse.

When making the case for the social benefits of liberty, Mill tends to emphasize how unusual individuals can make discoveries that benefit the rest of society.

In my opinion, Mill is most impressive when he is making the case for individual liberty even when it will be misused. Mill’s opponents note that individuals do not always use liberty well. Mill grants the point and seeks to show that society should leave individuals at liberty nonetheless. If he succeeds, he will have defeated his opponents’ best argument.

What Liberty of Expression Is Not

Today’s class was about chapter two of On Liberty. The topic of this chapter is liberty of thought and expression. Mill seeks to show that society should never suppress opinions.

I started off by distinguishing expressions of opinion, which Mill says society may never regulate, from other kinds of speech, which I think he should allow society to regulate. For example, I think that society can legitimately prevent people from publishing instructions on how to make nuclear weapons or other people’s private information. I would be surprised if Mill did not agree. The expression of opinion is different than the publication of facts. Mill is arguing for near absolute protection of the former while not saying much, as far as I can see, about the latter.

There is one other qualification that is important to bear in mind. Mill thinks society should not eliminate the expression of an opinion. He does not think that it cannot regulate the expression of an opinion. If you look at the beginning of chapter 3, he makes this quite plain. Everyone should be allowed to express the opinion that the corn dealers are starving the poor. But the state can prevent someone from expressing this opinion in front of an angry mob that is ready to riot.

No one pretends that actions should be as free as opinions. On the contrary, even opinions lose their immunity, when the circumstances in which they are expressed are such as to constitute their expression a positive instigation to some mischievous act. An opinion that corn-dealers are starvers of the poor, or that private property is robbery, ought to be unmolested when simply circulated through the press, but may justly incur punishment when delivered orally to an excited mob assembled before the house of a corn-dealer, or when handed about among the same mob in the form of a placard. Acts, of whatever kind, which, without justifiable cause, do harm to others, may be, and in the more important cases absolutely require to be, controlled by the unfavourable sentiments, and, when needful, by the active interference of mankind. (ch. 3, par. 1)

When I mentioned this, Sabrina and Taylor asked about what Mill would say about safe spaces or so-called PC culture. Briefly, I think it would turn on whether the attempts to establish a safe space involve preventing speech that is harmful to others or speech that is merely offensive. I said that we would pick this up next time, when we discuss Mill’s position on liberty of action (and read chapter 3!).

Mill’s Arguments for Freedom of Expression

Mill makes two broad points in favor of freedom of thought and expression.

  1. No one can ever have enough confidence that their own opinions are true (and contrary opinions are false) to justify suppressing the contrary opinions.

  2. Even someone who was certain that an opinion is false should not suppress it.

In both points, Mill assumes that suppression will always be favored on the grounds that the opinion being suppressed is false. That is what those doing the suppressing will believe.

His first point is that no one can have good enough reason for believing that an opinion should be suppressed on the grounds that the opinion is false. In order to establish this, he first proposes standards that would have to be met in order to have good enough reason to suppress an opinion. Then he argues that these standards cannot be met.

The first standard Mill proposes is that those who wish to suppress an opinion must be certain that it is false (ch. 2, par. 5). This is a very high standard: we don’t hold that people who have to make other momentous decisions have to be completely certain. We do not require public officials to be certain before they put people in prison or start wars, for instance. Mill would need to show that the decision to suppress an opinion is different in kind than every other kind of decision in order to explain why it should be held to this very high standard. I do not think he can do this.

Mill recognizes the problem and moves to a different standard: we are justified in thinking that an opinion is false only if those who hold it have “every opportunity” of supporting their views and the “complete liberty of contradicting and disproving” our contrary opinions (ch. 2, par. 6). That condition can only be met if opinions are never suppressed, of course. So, Mill concludes, we are never justified in suppressing an opinion.

While Mill’s argument is clever, I do not think that it supports his conclusions. Suppose we permit thorough debate before deciding to suppress an opinion. Then we would have met the standard and we could be justified in suppressing the opinion, contrary to the conclusion Mill wanted to establish.

Taylor disagreed with me here. He said that Mill could reply that you never know whether you have heard all of the objections to your opinion unless you leave others at liberty to express any objection they see fit. Nice point! It fits very well with Mill’s general point that we are reluctant to think of problems with our own opinions and so we need others to bring the problems up. However, I wonder if it would carry Mill as far as he wants to go. Could we suppress the contrary opinions we have already heard while allowing new contrary opinions? Mill wants to support liberty for all expressions of opinion, whether new or old.

Even if I am right, Mill still has his second point that false opinions should be tolerated on the grounds that doing so is necessary for ensuring that those who hold true opinions understand the reasons for their beliefs. If that argument works, we should not suppress an opinion even if we are sure it is false.

Mill’s argument is that even true beliefs will be held as what he calls “dead dogmas” if contrary opinions are not discussed.

Let us now pass to the second division of the argument, and dismissing the supposition that any of the received opinions may be false, let us assume them to be true, and examine into the worth of the manner in which they are likely to be held, when their truth is not freely and openly canvassed. However unwillingly a person who has a strong opinion may admit the possibility that his opinion may be false, he ought to be moved by the consideration that however true it may be, if it is not fully, frequently, and fearlessly discussed, it will be held as a dead dogma, not a living truth. (ch. 2, par. 21)

If Mill can make this argument stick, he will have a case against the suppression even of false opinions: that even true beliefs will be lost if they are not confronted with false ones. The idea is that those who hold the true beliefs will not understand them if they are insulated from the expression of contrary opinions, even if they are false.

Is It a Utilitarian Argument?

Mill takes for granted a link between having true beliefs and producing social utility. That is the only way that his arguments about truth would be relevant to a utilitarian.

At a minimum, Mill should have explained how the connection between true beliefs and utility is made. But even if had done so, a utilitarian will need to know more before agreeing with Mill’s libertarianism. Open discussion of opinions may well be vital for ensuring that truths are understood rather than being held as dead dogmas. But there can be a cost to open discussion as well that a utilitarian will weigh against that benefit.

For example, some people believe that childhood vaccination leads to harmful side-effects, such as autism. Those who disagree with them believe that they have simply confused correlation with causation: vaccines are typically administered right before the symptoms of autism typically appear making it look like they are the cause of those symptoms.

Mill believes that a free and open discussion of this question will lead to a deeper understanding of the nature of vaccines and autism, one way or the other. He is probably right about that, at least, for many people. But while the matter is under discussion, many people will refuse to vaccinate their children because they have heard that vaccines might cause autism. There are clear costs to doing that. Many children will get seriously ill and some will die from diseases that could be easily prevented.

A utilitarian will have to weigh the costs and benefits of full discussion before agreeing with Mill. The fact that full discussion is the best path to true belief in the long run is only part of the case for a utilitarian. All the short run costs count too.

One other thing that a utilitarian will do is look at the different ways of suppressing an opinion. Mill is most interested in the use of the state’s power by, say, punishing those who express unpopular opinions. But he is also opposed to informal social pressure towards conformity. A utilitarian might agree with him that the state should not punish those who express the opinion that vaccines are harmful while disagreeing with the suggestion that there should be no social pressure on them as well.

Key concepts

  1. How Mill argues that individual liberty benefits the individual.
  2. How Mill argues that individual liberty benefits society.
  3. How Mill argues against the suppression of opinions in particular.


Mill, John Stuart. (1859) 2000. On Liberty. Edited by Mark C. Rooks. British Philosophy: 1600-1900. Charlottesville, VA: InteLex Corporation.