(2025-04-11) Alexander Come On Obviously The Purpose Of A System Is Not What It Does

Scott Alexander: Come On, Obviously The Purpose Of A System Is Not What It Does. (POSIWID) Consider the following claims: The purpose of a cancer hospital is to cure two-thirds of cancer patients.

The purpose of the Ukrainian military is to get stuck in a years-long stalemate with Russia.

These are obviously false.

Am I being unfair here? Maybe the slogan “the purpose of a system is what it does” was never meant to apply to situations like these?

It’s only used for galaxy-brained claims like “The purpose of a system is what it does! The police do a bad job solving crime, therefore the purpose of the police must be to tolerate crime, no matter what you gullible starry-eyed idealists who take the police’s story at face value might think!”

Here the correct response is that the police might try to solve crime, but fail

*Or someone might say “The police sometimes brutally beat suspects. Therefore, the purpose of the police is to control and intimidate the population by brutally beating them. You can’t claim that this is just a mistake or a side effect - the purpose of a system is what it does!”

Here the correct response is that you can absolutely claim it is an unfortunate side effect*

These people are just taking the single worst and least-desired side effect of a system, then asserting that this - and not any of the much more reasonable things that the system does - must be its one true purpose.

If you feel tempted to say “the purpose of a system is what it does”, I recommend at least coming up with some novel rephrasing. How about “No system has ever failed at its purpose”? Or “There is no such thing as an unintended consequence”? At least then everyone would know where you stand!