Political Philosophy Spring 2021

Mill on Liberty of Expression


In the first chapter of today’s reading, Mill explains why he thinks that democracy raises a new question about political liberty, articulates the principle for determining when society may limit liberty that he will defend (this is known as the harm principle), and makes clear that he intends to argue for the harm principle on utilitarian grounds.

In the second chapter, Mill addresses one specific case: freedom of thought and expression.

He will make his case for liberty of action in general in the chapters we will discuss in the next class.

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 individual benefits of 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.

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 is 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.

There are two qualifications that you should bear in mind here.

First, I think it is helpful to distinguish 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 other people’s private information or instructions on how to make nuclear weapons. 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.

Second, Mill thinks society should not suppress 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)

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.

Mill’s standard holds that 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. Ta da!

On the face of it, this standard is too high. All that you need is to have enough evidence to justify suppressing an opinion at some point. Once you have that level of evidence, you are justified in suppressing the opinion. You don’t need to continually amass more evidence or reconsider your conclusion. Enough is enough, after all.

Even if that objection is correct, 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)

I think this is worth discussing. If this argument is correct, then the state should not suppress anyone’s opinions. But it appears to have more far reaching implications since it seems to hold that my beliefs will be “dead dogmas” if I do not consider all opinions.

Let me explain why that might matter. I think it’s rational to ignore the opinions of people who I think are arguing in bad faith or opinions that strike me as wildly implausible. There is only so much time in the day and my time is better spent with opinions that are closer to the truth as I see it. Would Mill say that this is irrational and that any beliefs I form will just be dead dogmas? I think it’s worth discussing the question.

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.

I want to make special note of this last point. Mill is taking on his opponent’s strongest case: an opinion that is known to be false. What value is there in allowing people to express that? He’s got an answer. What is so great about Mill is that he thinks ahead and anticipates the best thing that someone who disagrees with him might say. Whether you agree with his argument or not, paying attention to how he conducts his argument is extremely valuable.

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.

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.