John Stuart Mill’s “On Liberty”: The Importance of Free Expression

This winter, as I have written about previously, I had been on a quest to read a number of the classics of western political thought, fueled by my desire to identify for myself a coherent understanding of the type of political goals that our society – and by extension, our schools – should be aiming toward.  For a variety of reasons that quest has been more difficult this spring than it was during the winter, but nevertheless I have continued it, albeit slowly, with my most recent (partial) reading.

John Stuart Mill’s “On Liberty” represents a unique place in the western liberal canon.  It was only written in 1859 – almost 200 years after John Locke’s most famous work: closer to Kennedy and Reagan than to Locke or Hobbes.  As a result, it’s a book that takes up its starting point as the period of post-Lockean natural rights-based democratic rule.  Mill kicks of the first chapter by establishing this fact: the notion of self-rule being the dominant mechanism in the societies toward which he is aiming his message in this book.  At first, he writes, self-rule seems immune from tyranny; after all, you can’t be tyrannical over yourself, right?  But you can have – as de Tocqueville knew – a tyranny of the majority, the repression of the minority on the part of one’s fellow citizens – a repression based in formal law and informal social coercion.  

From this situation, Mill tells us at the outset that his goal is to try to answer a very simple question: What are the “nature and limits of the power which can be legitimately exercised by society over the individual”? (5).  This is a question – “where to place the limit” (9) – on which he writes that “nearly everything remains to be done” (9).  Soon, Mill answers the question, summoning up his famous Harm Principle: Power can only be exercised over individuals in order to prevent harm to others.  Power cannot be used to do something on a person’s behalf, nor because a large majority is in favor of it.  It is only when it can “be calculated to produce evil to someone else” that power can be exerted over the individual; when it comes to that which is his own – his own conscience, his own beliefs, his own body and mind, “the individual is sovereign” (13).

Yet interestingly, although Mill is very consciously writing in a post-Lockean, rights-based, largely democratic context, his Harm Principle is based on utilitarianism, not on natural rights.  Mill, for instance, doesn’t believe that the Harm Principle applies in what he calls “backward states of society”; “Despotism,” he writes, “is a legitimate mode of government in dealing with barbarians, provided the end be their improvement, and the means justified by actually effecting that end” (13).  So much for natural rights doctrine!

Mill is conscious of this, acknowledging that he will “forego any advantage which could be derive to my argument from the idea of abstract right, as a thing independent of utility” (14).  Yet it is “utility in the largest sense,” he writes, “grounded on the permanent interests of man as a progressive being” (14).  Later he says that this makes mankind “greater gainers” (16), but other than that, he does not reveal in the first chapter just what utilitarian basis his defense of individuality rests on.  To what extent he is clear about this in the second chapter, I’ll comment on later.  Meanwhile, Mill does outline three specific basic liberties whose protection he intends to discuss, and his says he’ll start with the first, freedom of thought.  

Here begins the most famous chapter of free speech ever written, and one of the finest chapters of philosophy I have ever read.

I should say about the introduction, before I move along to considering the next section, that Mill is an outstanding writer.  He’s lucid, expressive, fluid, crisp.  He walks that fine line perfectly between being engaging and informative but economical.  I’m not sure I’ve ever met a more concise but articulate writer in all of the philosophy I’ve read.  Mill’s summary in this intro section about the history of civilizations and their relation to individualism is so amazingly tight and yet so brimming full with ideas and truth.  He’s both a genius-level intellect – clearly – and an admirable prose stylist.

Next I’ll consider his famous chapter.

Chapter II:  Of the Liberty of Thought and Discussion

In this, arguably his most famous chapter, Mill outlines the case not only for toleration of divergent opinions, but for welcoming them as critical aids to the process both of attaining truth and for holding it more securely.  

The first thing to reiterate is that Mill’s case for free expression is apparently utilitarian.  This is not a book about a Lockean sense of the inherent worth or right of each person, and by extension the inherent right to personal expression free from coercion.  Nor is Mill’s chapter focused – at least directly – on the political or social importance of freedom of thought; there is nothing in here of Jonathan Rauch’s insistence, in Kindly Inquisitors, for example, that liberal societies must fight with their words, lest they fight with their guns, none of the Madisonian notion of democracy as a set-up of checks and balances that pits ambition against ambition and sees the expression of conflicting ideas as a necessary “safety valve” to release pent-up political frustration and to defuse factionalism.

Why is Truth Important?

So what is Mill’s utilitarian argument in favor of free expression?  It’s a little oblique, I think.  The first step is easy to make: Free expression – the avoidance of both formal and informal, legal and social, sanctions against dissident voices – leads both to a better understanding of what is true, and to a better understanding of why it is true.  And yet the question of why truth is important is one that Mill is, at best, unclear about.  One might have expected him to begin the chapter by establishing the utilitarian benefit of true knowledge – that’s not hard to do, I’d imagine – and there are many ways of doing so.  But Mill never does.  He’s certainly not defending freedom of expression on the part of heretics as a means of discovering everything about reality as is possible (an argument I’ve often heard FIRE president Greg Lukianoff make).  Perhaps he simply takes it for granted that truth is valuable, although one worries somewhat in response to some of Mill’s own objections in this chapter, such as the classic Platonic political argument in favor of restricting speech within the “polis” that Mill himself raises:  “There are, it is alleged, certain beliefs, so useful, not to say indispensable to well-being, that it is as much the duty of government to uphold those beliefs, as to protect any other of the interests of society” (25). This is a powerful objection – a utilitarian one, based on a conception of political utility and stability, and one hopes that Mill is prepared to fire back with guns blazing about the inherent or at least utilitarian value of true belief.  Yet his response is surprisingly low-key, almost a technicality: any such Platonic thinkers and would-be statesmen who would not only hold a firm belief about public utility, but forbid discussing others – are only assuming their infallibility, and, one can infer, making mistakes in their governance.  Mill writes, “The usefulness of an opinion is itself matter of opinion: as disputable, as open to discussion, and requiring discussion as much, as the opinion itself” (25).  In other words, anyone who believes they have an opinion so important that society would break down without it would need to have even that opinion constantly tested in order to really believe it to be true.  This seems to draw us uncomfortably close to a strange paradox: something akin to, “The only way you can have an unquestioned belief is if it can be questioned.” But I think Mill’s broader point, which he is not especially clear about, is that it’s simply not useful, not conducive to improving people’s lives, to get things wrong.  Mill writes, “ . . . no opinion which is contrary to truth can be really useful” (25-26).  The assumption of infallibility, from what I can tell, is the surest way to start making mistakes, which runs directly counter to his utilitarianism.

Mill reminds us of several historical examples of human beings assuming their own infallibility and thereby getting things horribly wrong – in a way, it is implied, that harms rather than helps humanity.  Mill cites a variety of examples of those who have gotten it wrong and persecuted many of the best and noblest people and ideas of various eras.  These mistakes were made by individual men (even broad-minded and tolerant men, like Marcus Aurelius), advanced civilizations (Athens, in the prosecution of Socrates), and entire historical eras (he describes the persecution of Jesus).  He writes, that “every age, having held many opinions which subsequent ages have deemed not only false but absurd; and it is as certain that many opinions, now general, will be rejected by future ages, as it is that many, once general, are rejected by the present” (22).  He specifically focused on mistakes of infallibility in which it was decided that a belief must be persecuted not just because it was wrong, but because it was immoral or impious.  “These,” he writes, “are exactly the occasions on which the men of one generation commit those dreadful mistakes, which excited the astonishment and horror of posterity” (27).  And here is proof of Mill’s genius – what a clever extension of his point: 

“It is among such that we find the instances memorable in history, when the arm of the law has been employed to root out the best men and the noblest doctrines . . .  though some of the doctrines have survived to be (as if in mockery) invoked, in defence of similar conduct toward those who dissent from them, or from their received interpretation: (27).  

What a wonderful passage, a sly take on the fallibility of humans.  And yet it is here that I believe one best understands Mill’s utilitarian value placed on truth (and by extension, on free expression): The assumption of infallibility leads away from truth; and it is only through truth and true understanding that one determines what is really useful for human beings.  Mill therefore sees truth as a public good.  As a result, he maintains that the suppression of diverse opinion is a public, not just private injury – he talks about how the silencing of dissidents is “robbing the human race” (20).  Mill writes that the greatest harm done by viewpoint repression is not necessarily to the great intellects, but to the ordinary people who are unable, in an environment of repression, to “attain the mental stature which they are capable of” (36).  

Clearly I do not fully understand Mill’s utilitarianism, which is not surprising because I’m only halfway through this book (the only one of Mill’s that I have read in the past twenty years).  But I think I can see the outlines of why he believes that truth is important.

Mill’s Epistemology

Mill’s defense of free thought also leads him into epistemology.  Mill stresses that humans are deeply fallible, as he puts it, and that we must approach our own understanding of the truth at all times with great humility; surely, history instructs us, we are bound to be wrong about lots of and lots of things – even big, important issues.  Yet what is critical is that our errors are “corrigible” (23) – we are capable of fixing our errors through discussion and experience, and in particular, by examining counterpoints and alternative hypotheses.  Mill’s ideal of truth is something of a falliblist’s: it is something we can only be fairly certain of, but never entirely certain, and we can only be as certain as possible when we have heard all cases against it and disproven their worth.  He writes, “The beliefs we have the most warrant for have no safeguard to rest on, but a standing invitation to the whole world to prove them unfounded” (24).  If the challenge of these ideas is met and answered, then, “We have done the best that . . . human reason admits of” (24).  In the meantime, we can “hope that if there be a better truth, it will be found when the human mind is capable of receiving it” and in the meantime we have attained “the amount of certainty attainable by a fallible being” – and “this is the sole way of attaining it” (24).  This, to me, is Mill’s epistemology – fallibilism, and it’s certainly what we think of as undergirding the epistemology of the modern scientific process.  It’s about being humble, about keeping one’s mind open, about treating contrasting viewpoints as a gift for either learning new beliefs, or sharpening existing beliefs. 

He writes, too, about “negative logic” – the pointing out of errors or weaknesses without necessarily conjecturing something in its place.  Mill says that this practice – which I think we would call “critiquing” or even “critical thinking” today – is out of fashion in his time, but has real value for a solid understanding of truth.

Truth, then for Mill, is like an ideal: something you can get closer and closer to, and which you certainly *can* hold with some degree of certainty, but only by a “standing invitation” to disprove it.  

The Value of Critique:  Holding Truth More Securely

Mill’s emphasis, as I mentioned before, is on the key distinction he makes between holding true beliefs and really knowing the truth.  For Mill, merely to hold a true belief – in the manner of just another prejudice, as he puts it – is not nearly as desirable as really knowing the truth, which Mill believes requires one to understand the reasons it is true, which he further argues requires an understanding of the opposing arguments.  

The problem with the repression of alternative viewpoints is two-fold.  First, the suppressed opinion may be true, or partly true, in which case we’re missing out on the chance “of exchanging truth for error” (20), or, even if the alternative view is false, we’re missing the chance at “the clearer perception and livelier impression of truth, produced by its collision with error” (20). 

Mill is especially good on this point, when he considers Argument “Two”: that even if one’s current, received opinions are true, and the heretical ones, which are suppressed, are false, humans are still losing out – and it is because they lose the chance to test their truth by debate and discussion.  A true belief, he writes, if not “fully, frequently, and fearlessly discussed . . .  will be held as a dead dogma, not a living truth” (37).  Given this importance of truth, he sees the protection of alternative viewpoints as being of greatest importance – in fact, he writes in a famous quote, “If all mankind minus one, were of one opinion, mankind would be no more justified in silencing that one person, than he, if he had the power, would be justified in silencing mankind” (20). Once again, it’s important to recall that Mill is not arguing this from a natural rights perspective, but from a utilitarian perspective – we’re not protecting gadflies because they’re human beings with innate worth and rights, but because it’s useful to have dissidents and diverse thinkers around to force us to clarify or to augment our ideas.

Because “dead dogma,” for Mill, does not constitute real knowledge – even if it is “true” – but only mere opinion or belief.  If we are to cultivate our minds and understandings, writes Mill, we must start by understanding the grounds of our own beliefs, and to do this, we must test them against contrasting opinions.  And it is not enough, he tells us, for a student to hear objections from his teacher; instead, in a passage worth quoting in its entirely, Mill writes:

“He must be able to hear them from persons who actually believe them, who defend them in earnest, and do their very utmost for them.  He must know them in their most plausible and persuasive form; he must feel the whole force of the difficulty which the true view of the subject has to encounter and dispose of; else he will never really possess himself of the portion of truth which meets and removes that difficulty” (38-39).  

Mill gives a short history of beliefs to illustrate his point.  At first, when a belief is new and perhaps subversive, its meaning is deeply felt and understood by believers.  Soon it either becomes common understanding or its progress stops; either way, it loses momentum and eventually becomes something “inherited” rather than “adopted” by new believers.  Since it no longer needs to defend itself, its real meaning is often forgotten and obscured.  There is a great deal of truth to this analysis – what Mill says about creeds or beliefs feeling vital when they’re still fighting criticism – and then gradually subsiding into just another school of thought is, in my view, amazingly accurate.  As Mill puts it, “Both teachers and learners go to sleep at their post, as soon as there is no enemy in the field” (44).  Mill furthers the metaphor by calling it – in the words of another author – “the deep slumber of decided opinion” (44).  

Epistemologically, Mill does not believe this means that truth stops being “truth” the moment that all humans agree on it.  In fact, Mill does believe that as time goes on, more and more “truth” will come to be known about the world, yet he takes his own objection about the loss of truth’s vitality quite seriously.  Once again, it is his key distinction between what is true versus how securely we know it is true.

Educational Implications

Given the importance of both attaining the truth and of holding true beliefs in a secure fashion,, Mill believes that it’s especially important for teachers to play devil’s advocate, or to arrange opportunities for students to hear real debate about topics, to make them combat common objections and thereby to feel the truth more acutely and more persuasively – “as if they were pressed upon him by a dissident champion, eager for his conversion” (45).  

The best historical example of this, for Mill, are the Socratic dialogues, which held the purpose of “convincing any one who had merely adopted the commonplaces of received opinion, that he did not understand the subject – that he as yet attached no definite meaning to the doctrines he professed” (45-46).  Instead, the Socratic dialogues point the way toward a more “stable belief” anchored in a firmer understanding of both the objections to and grounds for one’s opinions.  

Seen this way, the Socratic method is an educational tool designed to draw out students’ held convictions, demonstrate to students how little real understanding these ideas rest on, and hopefully push students to find firmer footing for their convictions.  It is teaching students to clarify their own beliefs or to change their own beliefs, while also teaching them how to defend their beliefs against criticism, and perhaps – if we are stretching – teaching them to, as Mill advises, welcome critique and criticism as a way of clarifying or improving their thought and work.  


John Stuart Mill does not disappoint.  This second chapter is surely the most powerful defense of freedom of thought and inquiry (and by extension, free expression) that I have ever read.  Start with the the writing – crisp, insightful, winning.  After slogging through Dewey the other month, what a welcome respite.  Then consider Mill’s format: for a man who believes truth is best seen by the collision of (sometimes contrived) diversity of viewpoints, Mill walks the walk.  Nearly every argument he advances is no sooner put to page than it’s assaulted by some strong counter argument he himself has raised – only for this would-be attacker to be soundly beaten back in turn.  It’s easily the best example of this point/counterpoint format I have ever read.  

In a sense, it seems to me that everything about inquiry that I like either comes from Mill or is well-reflected in him.  The ideal of fallibilism – epistemic humility, disconfirmation, empiricism, none of these is new from Mill, but never have these ideas been better and more elegantly articulated.  What seems very new to me in Mill’s work, however, is his insistence that we must not only know truth, but we must understand it in a living, feeling way, and we must be able to answer its most worthy criticism.  

What exactly is modern liberalism?  It’s surely something to do with John Stuart Mill: his focus on the individual’s rights, his epistemic fallibilism – the belief that humans are fallible and should therefore adopt a stance of epistemic humility and a welcoming of divergent viewpoints in order to better hash out what the truth – which is always provisional – really is.  It all harkens back to John Locke, to the birth of empiricism – the notion that individuals could observe reality and didn’t need to take accepted reality based on the authority of society or of the church.  Some months back I wrote about Locke:

Moreover, we should practice not only epistemic humility, but collective inquiry toward a better understanding.  We should “endeavor to remove” our mutual ignorance “in all the gentle and fair ways of information” – which is to say through reason and observation – in order to “spend the days of this our pilgrimage with industry and care, in the search, and following of that way, which might lead us to a state of greater perfection” (576).  This, to me, seems like another creed of the Enlightenment forming: the notion that through rational inquiry and study of reality, we can better know truth, and therefore improve our earthly state.

It seems to me, as I search around trying to understand a philosophy for myself, that some combination of Locke’s empiricism and Mill’s fallibilism are at the heart of what I believe in.  As I wrote above, I still don’t fully understand Mill’s utilitarianism, but his notion that truth is critically important both to discover and to really understand, seems to me of vital importance.