Prescriptivism and Descriptivism

On the internet and in newspapers, it's not uncommon to see rants about how our language is deteriorating. Words that meant one thing fifty years ago are used completely differently today. New words are made up and used as if they were cromulent. Kids these days speak grammatically uncorrectly.

And generally there will be responses to those about how that's a prescriptivist way of thinking, and prescriptivism is linguistically incorrect. Descriptivism is the only correct way of talking about language. Language is always changing, and words have no inherent meaning.

While in this context, the prescriptivists are usually completely wrong, I can't completely agree with descriptivists.

It's true that linguistics is descriptive. As a science, it has to be. The goal of linguistics is to study language to learn about how it works, and you can't learn about how something works by telling it to work differently. Kepler didn't discover the laws of planetary motion by insisting that they ought to orbit the sun in perfect circles.

But the scientific study of language is not the only way to interact with it. It's not even the most common way. The most common way of using language is the way we're using it right now - to communicate. Reading, writing, speaking, listening. And when you actually use a language, not just to study, but to communicate, you can't avoid being at least a little bit prescriptivist.

If you're trying to use words to communicate, you have to ascribe meaning to them. And if the meanings you ascribe to your words are different than the meanings the people you're trying to communicate with do, then you'll have a very hard time communicating. If you want to communicate with a large group of people, you have to get them to all use the same meanings for the same words. Words don't have inherent meaning, but it's a very useful fiction.

If You Can't Explain It...

There is a common saying with a variety of forms that generally goes like this:

If you can't explain it simply, you don't understand it well enough.

You do not really understand something unless you can explain it to your grandmother.

If you understand something, you can explain it in its simplest form.

If you can't explain it to a six year old, you don't understand it.

I disagree with this saying. The ability to explain something well is a skill separate from the thing you're trying to explain.

Consider a watchmaker who can make intricate watches that work correctly, but who can't tell you why certain pieces go where they do. Not only can he build watches, but he can also innovate designs to make them better. Does he understand watchmaking? Clearly, he does, otherwise he wouldn't be able to make them work at all. His inability to explain is a problem with his communication skills, not a problem with his understanding.

Further, how difficult something is to explain depends not only on how well you understand it and how good you are at explaining, but also who you're explaining it to. This is the concept of inferential distance. It's a lot easier to explain calculus to someone who understands algebra than it is to explain it to someone who doesn't even understand arithmetic.

And if you're really good at certain forms of communication, you can explain something that you don't understand at all (though not correctly).

Inferential Distance

Suppose you're trying to teach someone calculus. Before they can learn calculus, they have to learn algebra. Before they can learn algebra, they have to learn arithmetic. This is the basic idea of inferential distance - background knowledge needed the understand the matter at hand.

Put this way, it looks simple, maybe not even worth talking about. But it's more subtle than that. To start with, arithmetic, algebra and calculus aren't single subjects. They're a whole bunch of related but still different subjects, which need to be learned independently. The learn integration, you have to learn differentiation, before that you have to learn limits, before that functions, variables, division, mulitplication, subtraction, addition... And don't forget the really fundamental things like what a number is.

And that's the really tricky part of inferential distance. There are a lot of things you know that you don't know you know. That is to say, you know them so well, it doesn't even occur to you to that someone else might not know it. Things that are so fundamental to your point of view that they're invisible to it. And so when you try to explain something to someone, you accidentally skip over a bunch of inferential steps, resulting in misunderstanding and each party will walk away thinking the other is stupid or crazy.

Consider a biologist talking to a creationist. They might try to explain the evidence for evolution, but before the creationist can understand that, they have to understand what evidence means, how science works, maybe even something as simple as why truth is important...