Freedom of thought, belief, speech, and expression is a principle long cherished in the West. In recent years it has come under the most sustained attack I have seen in my lifetime, from multiple quarters. I believe it is worth defending, and it’s time to say more about why.

On Liberty, generally attributed to the English philosopher John Stuart Mill, is the most famous and widely cited defence of this principle, and for good reason. I had a low opinion of Mill for a while, as his Utilitarianism did a bad job, overall, of defending the utilitarianism I broke from – and that was one of the key reasons I broke from it. But On Liberty is an entirely different story. It provides a powerful and, I think, largely correct defence of free thought and speech on two grounds – neither of which is particularly utilitarian!

Perhaps the difference is because it now seems likely the book was co-written with Harriet Taylor Mill, John Stuart’s wife – probably published without the woman’s name on it to make a Victorian audience to take it more seriously. (For that reason I’ll refer to On Liberty as written by “the Mills”.) It might be that Harriet was less of a utilitarian than John. But the point here is the two big grounds that the Mills provide for why freedom of speech is important.

The first of these grounds is truth: that is, free expression allows us to better discover truth. Let’s start with one way not to think about this idea: the “marketplace of ideas”. Markets do not necessarily allow the best products to win; ask the partisans of WordPerfect or Betamax VCRs. The market allows rich donors to promote and spread bad and false ideas at the expense of good and true ones. More generally we have seen clearly in the last several years how unfettered speech does not mean the true ideas become the most popular ones. In the words of Harvard law professor Noah Feldman, “It’s inexpensive — and in fact cheaper — to produce lies rather than truth, which creates conditions for a lot of false information in the marketplace…” The argument for free speech should not be that it makes true ideas become popular. I imagine anyone who once believed in free speech on those grounds would have understandably become an advocate for censorship by now. Many probably have.

The marketplace metaphor obscures the way in which free expression actually allows us to discover truth. The more important way in which this happens, which the Mills defend in detail, is epistemic humility. That is: We finite human beings can never be fully certain about truth; there is always so much more out there we haven’t thought about. We should be seeking truth, but we can never assume that we have found it. The Mills, attuned to science, notes that what gives us the most justification to believe our beliefs is “a standing invitation to the whole world to prove them unfounded.” So the late Alasdair MacIntyre rightly reminds us that we should aim to inhabit whatever perspective and tradition we can view as the best story so far. But that story too is subject to overturning by future stories that might be better. Thus University of Virginia philosopher Elizabeth Barnes provides a powerful account of how much better she thinks when she has conversations with opponents. Hearing other stories brings us closer to the truth.

Now here is the key: those other stories can only bring us closer to the truth if we hear them. And that is the great problem with censorship of all kinds – that is, with punishing people for the content of their ideas. When people do not speak their ideas out of fear of punishment, we can no longer learn from them and come closer to the truth – and that means we cannot have nearly as much confidence that the ideas we do hold are in fact true. For we have rejected the standing invitation on which our confidence in our beliefs can stand. As the Mills rightly say, “He who knows only his own side of the case, knows little of that. His reasons may be good, and no one may have been able to refute them. But if he is equally unable to refute the reasons on the opposite side; if he does not so much as know what they are, he has no ground for preferring either opinion.” (68) When we prohibit ourselves from thinking about a wrong view and the details that make it wrong, we can no longer know whether it is wrong – and therefore cannot know whether it is right. Leaving ideas uncensored does not mean that the truest ideas will become the most popular or widespread ones; but it does mean that they will be available for those of us who actually seek truth. To seek and find the truth in that way is both pragmatically beneficial and, I would argue, a good in itself.

This all is particularly important for the ideas of academics and journalists: people whose job it is to seek out truth in ways more rigorous or demanding than others can, to find ideas that would not otherwise see the light of day. Academics are those trained in, and tasked with, discovering truth. Truth is hard to find; we never have a guarantee that we’ve reached it. But few things are more important in the collective pursuit of truth than making sure that scholars are free to express their best educated attempts at reaching the truth they have sought. Academic freedom is a special case of freedom of speech: it comes with additional responsibilities, to hard-won academic disciplinary norms of establishing truth, but it is a particularly important kind of speech to protect.

In addition to truth, the Mills have a second grounding for free speech: grounds I have called expressive individualist. The Mills tell us that “If a person possesses any tolerable amount of common-sense and experience, his own mode of laying out his existence is the best, not because it is the best in itself, but because it is his own mode.” And they fret that society tends “to fetter the development, and, if possible, prevent the formation, of any individuality not in harmony with its ways, and compel all characters to fashion themselves upon the model of its own.” (8) Our individual teleology is something we need to express – something we cannot do if expression is not free. My thoughts, my ideas, are a fundamental part of who I am – that true self so valued by the transgender movement. The Supreme Court of India understood this well when they cited On Liberty in defence of gay rights. The expressive individualists of the 1960s understood this well, too, when they worked hard to reject conformity – what the Mills calls “the demand that all other people shall resemble ourselves.” It is exactly that demand that the censor imposes: her confidence in her rightness is so strong that she stifles deviation from it. (Thus it was natural for left-wing student radicals of the ’60s, so devoted to expressive individualism, to call their movement the Free Speech Movement.)

I believe that the Mills are right on both of these grounds. Freedom of speech is essential, both to foster the search for truth (though not in any sort of “marketplace”) and to allow us to express ourselves truly. For both the quest for truth and self-expression are deep and important human goods, constituent parts of the good human life.

They are not the only such goods, however. And that is where the question of free speech becomes thornier. Free speech is essential and needs protecting, but there are other human goods and political goods against which it needs to be weighed. That is where things begin to get complicated, and I will turn to those complexities in the next posts.