February 2022Writing about something, even something you know well, usually showsyou that you didn't know it as well as you thought. Putting ideasinto words is a severe test. The first words you choose are usuallywrong; you have to rewrite sentences over and over toget them exactly right. And your ideas won't just be imprecise, butincomplete too. Half the ideas that end up in an essay will be onesyou thought of while you were writing it. Indeed, that's why I writethem.Once you publish something, the convention is that whatever youwrote was what you thought before you wrote it. These were yourideas, and now you've expressed them. But you know this isn't true.You know that putting your ideas into words changed them. And notjust the ideas you published. Presumably there were others thatturned out to be too broken to fix, and those you discarded instead.It's not just having to commit your ideas to specific words thatmakes writing so exacting. The real test is reading what you'vewritten. You have to pretend to be a neutral reader who knows nothingof what's in your head, only what you wrote. When he reads what youwrote, does it seem correct? Does it seem complete? If you make aneffort, you can read your writing as if you were a complete stranger,and when you do the news is usually bad. It takes me many cyclesbefore I can get an essay past the stranger. But the stranger isrational, so you always can, if you ask him what he needs. If he'snot satisfied because you failed to mention x or didn't qualifysome sentence sufficiently, then you mention x or add morequalifications. Happy now? It may cost you some nice sentences, butyou have to resign yourself to that. You just have to make them asgood as you can and still satisfy the stranger.This much, I assume, won't be that controversial. I think it willaccord with the experience of anyone who has tried to write aboutanything nontrivial. There may exist people whose thoughts are soperfectly formed that they just flow straight into words. But I'venever known anyone who could do this, and if I met someone who saidthey could, it would seem evidence of their limitations rather thantheir ability. Indeed, this is a trope in movies: the guy who claimsto have a plan for doing some difficult thing, and who when questionedfurther, taps his head and says "It's all up here." Everyone watchingthe movie knows what that means. At best the plan is vague andincomplete. Very likely there's some undiscovered flaw that invalidatesit completely. At best it's a plan for a plan.In precisely defined domains it's possible to form complete ideasin your head. People can play chess in their heads, for example.And mathematicians can do some amount of math in their heads, thoughthey don't seem to feel sure of a proof over a certain length tillthey write it down. But this only seems possible with ideas you canexpress in a formal language. [1] Arguably what such people aredoing is putting ideas into words in their heads. I can to someextent write essays in my head. I'll sometimes think of a paragraphwhile walking or lying in bed that survives nearly unchanged in thefinal version. But really I'm writing when I do this. I'm doing themental part of writing; my fingers just aren't moving as I do it.[2]You can know a great deal about something without writing about it.Can you ever know so much that you wouldn't learn more from tryingto explain what you know? I don't think so. I've written about atleast two subjects I know well — Lisp hacking and startups— and in both cases I learned a lot from writing about them.In both cases there were things I didn't consciously realize tillI had to explain them. And I don't think my experience was anomalous.A great deal of knowledge is unconscious, and experts have ifanything a higher proportion of unconscious knowledge than beginners.I'm not saying that writing is the best way to explore all ideas.If you have ideas about architecture, presumably the best way toexplore them is to build actual buildings. What I'm saying is thathowever much you learn from exploring ideas in other ways, you'llstill learn new things from writing about them.Putting ideas into words doesn't have to mean writing, of course.You can also do it the old way, by talking. But in my experience,writing is the stricter test. You have to commit to a single, optimalsequence of words. Less can go unsaid when you don't have tone ofvoice to carry meaning. And you can focus in a way that would seemexcessive in conversation. I'll often spend 2 weeks on an essay andreread drafts 50 times. If you did that in conversationit would seem evidence of some kind ofmental disorder. If you're lazy,of course, writing and talking are equally useless. But if you wantto push yourself to get things right, writing is the steeper hill.[3]The reason I've spent so long establishing this rather obvious pointis that it leads to another that many people will find shocking.If writing down your ideas always makes them more precise and morecomplete, then no one who hasn't written about a topic has fullyformed ideas about it. And someone who never writes has no fullyformed ideas about anything nontrivial.It feels to them as if they do, especially if they're not in thehabit of critically examining their own thinking. Ideas can feelcomplete. It's only when you try to put them into words that youdiscover they're not. So if you never subject your ideas to thattest, you'll not only never have fully formed ideas, but also neverrealize it.Putting ideas into words is certainly no guarantee that they'll beright. Far from it. But though it's not a sufficient condition, itis a necessary one.Notes[1] Machinery andcircuits are formal languages.[2] I thought of thissentence as I was walking down the street in Palo Alto.[3] There are twosenses of talking to someone: a strict sense in which the conversationis verbal, and a more general sense in which it can take any form,including writing. In the limit case (e.g. Seneca's letters),conversation in the latter sense becomes essay writing.It can be very useful to talk (in either sense) with other peopleas you're writing something. But a verbal conversation will neverbe more exacting than when you're talking about something you'rewriting. Thanks to Trevor Blackwell, PatrickCollison, and Robert Morris for reading drafts of this.
