Mill’s Trident: An argument every fan (or opponent) of free speech must know

Free speech is critical whether you’re wrong, partially wrong, or totally right

I have been working on a comic book about free speech for years now,  and one of my goals for that project is to represent key free speech arguments in the visual way that comics do so well.

One of my favorite concepts from that work is what I call “Mill’s Trident.” It’s based on John Stuart Mill’s observation in his 1859 masterpiece “On Liberty” that in any argument there are only three possibilities: You are either wholly wrong, partially wrong, or wholly correct — and in each case free speech is critical to improving or protecting those positions.

In the scene I’ve envisioned, John Stuart Mill’s wife Harriet Taylor Mill, who was the inspiration and collaborator on much of Mill’s work — including his groundbreaking work on the rights of women — appears holding a literal trident, with each prong representing one of the following three points I’ve paraphrased from Mill’s book:

• If you are wrong, freedom of speech is essential to allow people to correct you. 

• If you are partially wrong, free speech and contrary viewpoints will help you get even closer to the truth. 

• If you are 100% correct (which is unlikely) you still need free speech for dissent, disagreement, and attempts to disprove you, both to check your arguments and to strengthen them. 

To download this gif, click here.

For many this last part is the least intuitive, but it’s also the most important. Why worry about dissent if you’re 100% correct? Well, if you never have to defend your points of view there is a very good chance you don’t really understand them — and if you don’t fully understand them, then you are holding them the same way you would hold a prejudice or superstition: irrationally.

It’s only through arguing with contrary viewpoints that we come to recognize not just whether what we believe is true, but why that’s the case. Throughout history, powerful people have elevated their own prejudices and superstitions to absolute truths and worked to protect them by censoring contrary viewpoints. Once the censorship failed (as nearly all censorship eventually does), those ideas were often exposed as wrong — but not before a lot of damage was done. 

Take, for example, the work of Trofim Lysenko. Lysenko was… I suppose we should call him a botanist? A “botanist” in the Soviet Union. From the 1920s to the late 1950s, his ideas dominated Soviet agriculture. Lysenko rejected Gregor Mendel’s genetic theory as “bourgeois” and “fascist” in favor of his own theories, which included that the changes a parent experiences in life can be inherited by their children. In Lysenko’s case, he believed that if you cause crops to flower early by exposing them to cold and moisture, the next crop based on those seeds will also flower early. This would allow the Soviet Union to maximize harvests of peas, wheat, and other crops by planting them all twice a year. 

It was a wonderful idea — only it was somewhat inconvenienced by being complete nonsense. It’s like trying to pass down a nose job to your kids. In a meritocracy, Lysenko would’ve been the office temp who sometimes talked about his failed career in agriculture. But in the Soviet Union Lysenko had the ear of the party in general and the support of Stalin in particular. So from the 1920s to the 1950s, Soviet agriculture was remade in the image of Lysenko’s fantasy botany.

Thousands of Soviet scientists who believed in genetics, that “whore of capitalism,” were fired or even imprisoned. As the Soviet Union “modernized” using Lysenko’s methods, crop yields went down and over five million died of famine. China followed suit and famine killed 30 million there. After Stalin died, the Soviet Union turned away from Lysenkoism, though Russia is flirting with these ideas again. (Sure, my last kids didn’t inherit the plastic surgery, but maybe if we rebrand it as epigenetic rhinoplasty my next ones…) 

We are rarely 100% correct, no one is anywhere near 100% correct all the time, and we often have no idea when we’re wrong. History will inevitably disprove an endless number of beliefs we currently have and are certain about. If we have never dug deeply enough into a belief to understand why it is true, and seriously considered the possibility that it is not, then even if we are right it is only by good fortune. That’s a bad method for operating in the world.

The ever-persistent and epistemically arrogant censorship hawks always try to ignore Mill’s Trident because they know they can’t defeat it. For any argument, there really are only these three possibilities Mill outlined, and free speech is necessary to fully benefit from all of those states. The trident, and the free speech that energizes it, is too powerful for anyone to evade forever. We’re all better off if we stop fighting Mill’s Trident and start working with it instead.

If you haven’t read “On Liberty,” by all means do so — particularly this illustrated version by my friend and “Coddling of the American Mind” co-author Jonathan Haidt. (Check out his Substack,

After Babel

). Mill’s book really is a masterpiece of argumentation, and there’s a reason why free-speech advocates come back to it over and over again.

“All Minus One: John Stuart Mill’s Ideas on Free Speech Illustrated”

Note: An earlier version of this piece was published on the FIRE blog in 2021. It is reposted here with some updates and revisions.

SHOT FOR THE ROAD

Check out this interview I did with Big Think on the evolution of free speech, the importance of having a robust free speech culture, and other themes from “The Canceling of the American Mind,” which I co-authored with Rikki Schlott.