"What are the benefits of ambiguous laws? "

Freedom and flexibility. Reality is infinitely complex, trying to encode real world problems 100% accurate into code can only work by rounding a lot, with the result of oversimplification with the result of lots of "unjust" rulings, when you do not take the intent of the law into account, but only the words. We have this problem already (a lot) many things that seem very wrong but are legal by the letters of the law.

(Mobsters being released because of formalities for example, even though everyone knee they were guilty)

I'd say, it's useful to distinguish between intentional and unintentional ambiguity/underspecification. For example, many jurisdictions that have statutory contract law have a statute that says that a provision in a contract is unenforceable if it is "unconscionable". There is, of course, a broad spectrum of things that can fall under that term, but that's intentional, i.e. the law maker specifically wanted to open a door there for a judge to hold a contractual provision unenforceable if they need it to be to get to a just outcome.

However, a lot of ambiguity, underspecification, and just plain sloppiness in language is there for no good reason and causes problems, and it would obviously be a good thing to get rid of that.

"However, a lot of ambiguity, underspecification, and just plain sloppiness in language is there for no good reason and causes problems, and it would obviously be a good thing to get rid of that."

100% agreed. When clear (and simple) rules are possible, vague rules just create opportunities for shady things. And yes, we have many, many laws that could be made simpler and therefore more clear. And if a programming language can help with that, that would be awesome.

But that doesn't mean freedom or flexibility for citizens. It means freedom and flexibility for the judiciary. For citizens, it takes away their freedom and flexibility because vague or contradictory laws (often coupled with severe penalties) create risk, or the perception of risk, where there wasn't meant to be any to begin with. It causes people to stop trying new things out of fear that Rule By Law will happen to them.

Whose freedom is more important? The people's, or their rulers? If you believe in enlightened rulers, you may legitimately conclude the latter, but for the rest of us, we'd rather the government be properly constrained. After all that's why laws are written down to begin with, it's why there is such a thing as the professional lawmaker.

Vague law is usually not written due to some deep philosophy of law making, after all. Nobody really tries to defend it in practice. It's almost always a result of lazy or politically contentious lawmaking when the people writing the laws don't really know what they want in the first place, so trying to divine their intent will never get you far.

"But that doesn't mean freedom or flexibility for citizens. "

It does, because if laws want to cover every case, they need to be so verbatim and rule out so many possibilities, that in the end, every action is encoded in law, which will result in people only doing things that are explicitely allowed. That limits a lot.

Simple example, despite being an adult, I like to climb trees. And sometimes also in parks. So I had discussions with officials or or wannabe officials about: is this allowed? It turns out, there is no rule allowing it. But there is also usually no rule forbidding it. But most people default to, if it is not explicitely allowed, it must be forbidden (which is a very german thing, but is not unique to us).

Michael de Montagne, a old french philosopher who is also quoted around this thread, put it way better in words. I try to find the passage.

Can ambiguity be quantified, and/or codified? Risking sounding like a painfully naive layman, would it be possible to define the range in which to apply the rule as function of range of inputs? When uncertaintu on inputs increases or veers outside of some well known range, then bandwidth for the judge increases?

I think something like this exists actually, even though I can't think of a concrete example, but I am sure it is not easy to implement (in a just way) either.

Laws very often look for intent of actions as well as the actions themselves.

And they are ambiguous: "beyond reasonable doubt" is what, as a percentage, in your view?

> What are the benefits of ambiguous laws?

That they can deal with the massive amounts of ambiguity & blurred lines / grey areas the world has to offer. Too many of our everyday concepts can’t be expressed rigorously for a formal encoding & determinate decision process - a famous example being obscenity’s famed “I know it when I see it” definition - and many are highly context dependent.