The Eternally Radical Idea

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

February 16, 2021

Key Concept Mill’s Trident: My term for the observation made by John Stuart Mill in “On Liberty” that, in any argument, there are only three possibilities (being wrong, being partially wrong, or being wholly correct), and every possibility is improved or strengthened by freedom of speech and inquiry.

I have been working on a comic book about free speech for years now, and I wanted a way to represent key free speech arguments in a visual way. “Mill’s Trident” refers to a three-part argument that John Stuart Mill made in favor of free speech in his 1859 masterpiece “On Liberty.” Mill recognizes that there are only three possibilities in any given argument: 

  1. You are wrong, in which case freedom of speech is essential to allow people to correct you.
  2. You are partially correct, in which case you need free speech and contrary viewpoints to help you get a more precise understanding of what the truth really is.
  3. You are 100% correct, in the unlikely event that you are 100% correct, you still need people to argue with you, to try to contradict you, and to try to prove you wrong. Why? Because if you never have to defend your points of view, there is a very good chance you don’t really understand them, and that you hold them the same way you would hold a prejudice or superstition. It’s only through arguing with contrary viewpoints that you come to understand why what you believe is true. 

(This is my restatement of his argument. Mill’s Victorian-era prose is gorgeous in context, but can be unwieldy to quote for modern ears.)

Throughout history, powerful people have elevated their own prejudices and superstitions to the third category, protecting them for a time by censoring contrary viewpoints. And once that censorship failed, as nearly all censorship eventually does, those ideas were often exposed as wrong.

We are rarely 100% correct, and no one is anywhere near 100% correct with everything they believe. History will prove us wrong about an endless number of beliefs we currently have. 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.

Usually, I connect the parts of the modular free speech arguments to a story in the news, but a few concepts are so important that I want them entirely on their own. Mill’s Trident is one of those.

And if you haven’t read “On Liberty,” by all means read it, particularly this illustrated version by my friend and “The Coddling of the American Mind” co-author, Jonathan Haidt. “On Liberty” really is a masterpiece of argumentation, and there’s a reason why free-speech advocates come back to it over and over again: it is a brilliantly constructed argument which all critics of freedom of speech must contend with seriously.