It makes me think of when people say that there's no sense in debating if a supreme court decision was correct, because the supreme court is the highest legal authority.
If they are correct by definition, then what are they doing to decide cases?
I would say that the purpose of something is what is proper or correct for it to do.
I think the slogan should not be taken literally and means more like "don't let the (possibly many-faceted and disputed) purpose of a system blind you to what it does".
It makes me think of when people say that there's no sense in debating if a supreme court decision was correct, because the supreme court is the highest legal authority.
If they are correct by definition, then what are they doing to decide cases?