I feel this is a facile interpretation of the phrase, kind of like complaining that "Measure Twice Cut Once" would lead to selling illegally adulterated flour. A more steel-man interpretation of POSIWID--the way I think it's intended to be understood--would be:

"The practical outcomes of a system over the long-term reveal something important of the the true-preferences of the various interests which control that system, and these interests may be very different from the system's stated goals."

> The purpose of a cancer hospital is to cure two-thirds of cancer patients... These are obviously false. The purpose of a cancer hospital is to cure as many patients as possible, but curing cancer is hard, so they only manage about two-thirds.

I don't see the contradiction here. The purpose of a cancer hospital is to cure as many patients as possible. "What it does" is cure as many patients as possible. The fact that as many patients as possible is currently (presumably) two-thirds is irrelevant. If major advancements in medicine or new types of cancer emerged which changed the percentage of people cured it wouldn't matter at all. "What it does" and "the purpose of the system" is still unchanged.

“If a system is maintained over an extended period and has observed behavioral traits that are consistent within that period, that is, in itself, strong evidence that those behavioral traits are consistent with the purpose for which the system is permitted to exist” is kind of a mouthful, though, and there is value in succinctness.

(Although there is another message, there, too: “the purpose of a system, insofar as it can be said to exist separate from what it actually does, has no weight in justifying the system’s existence or design”.)

Great read. I've always noticed that the type of argument invoked is often less telling than when and in which context you invoke that argument.

You can make a lot of claims and they can match to reality a lot - normally people think of evaluating things in terms of a strict "does this fit or does this not", but it's often the meta-style (why do you keep bringing up that argument in that context?) that's important, even if it's not "logically bulletproof".

Wow that post is bad. The author clearly never actually attempted to understand what POSWID actually means and where it is coming from. Perhaps, instead of looking at Twitter, they should have opened Wikipedia. Or, better yet, Stafford Beers books (though admittedly, he was a pretty atrocious writer).

The follow-up is slightly better. But still not very convincing, IMO. They get far too stuck on a literal interpretation. Of something that self-describes as a heuristic.