> Assume that those who came before you had good reasons for their actions

There's a limit to that assumption, though. I'm always inclined to assume that people had reasons, and that they looked good at the time, but without knowing what those reasons are, there's no way to know if the reasons are as good now as they were then, even if you make the charitable assumption that they were good reasons at the time.

I would be a big fan of the idea that legislation had built-in turnover clauses, for instance, that required renewal every N years (for a value of N not much larger than the turnover rate of legislators). Which then means if you want something to persist, you would have to document your rationale for posterity, and convincingly argue that that rationale still applies.

> I'd be curious to see a strong legislative version of this - enshrining the spirit of the law in the text, and giving courts explicit rights to strike down laws which no longer fulfill their original intent.

I agree completely. Laws should state up front that "the purpose of this law is to ...", and for that matter explicitly state any other relevant considerations or side effects and whether they're considered beneficial, undesired, or simply neutral. That would mean there would have to be at least a pretense of a sensible motive, and that interpretations that don't serve that motive could be thrown out.

> The Aereo suit, for instance, shouldn't have happened under any kind of intent-based legal system.

It still could have, depending on the intent. The intent of copyright law, for instance, is supposed to be "we want more works produced, but we also want more works to enrich the public domain, so there's a tradeoff". The intent was never about authors and what they want; that's a means to an end. However, that rarely seems to be reflected in deliberations.

> I would be a big fan of the idea that legislation had built-in turnover clauses, for instance, that required renewal every N years (for a value of N not much larger than the turnover rate of legislators). Which then means if you want something to persist, you would have to document your rationale for posterity, and convincingly argue that that rationale still applies.

Let's be honest. These things would mostly be just bundled up and passed all at once. Or, alternatively, they would be used as leverage like the budget currently is. Actually, it would pretty much be exactly like the budget at this point. It either sails through with no issues, or it begins months of partisan bickering.

EDIT: Also, could you imagine the kind of flex we might see on major laws? I can only imagine large sets of laws sunsetting every time the Congress majority changes... Hey, at least it will create a whole industry centered around these adjustments! That's job creation right there! And, as always, the lawyers will be making their money.

This would require lawmakers to agree on the intent of legislation in addition to its affects, which would be categorically harder because different people may favor a policy for different reasons.

It might be simpler to just sunset every law by default after some period and require lawmakers to periodically renew them - if a majority can't form to support renewal, then it's reasonable to assume the original motivation lacks support. It's also a handy way of nudging updates to the laws to keep up with current times.

> This would require lawmakers to agree on the intent of legislation in addition to its affects, which would be categorically harder because different people may favor a policy for different reasons.

While that doesn't seem like the main intent of such an approach, it certainly sounds like a beneficial side effect. New legislation is not a thing that should occur particularly often, or lightly.

> It's also a handy way of nudging updates to the laws to keep up with current times.

Agreed. (You'd also need to have some requirement to prevent any omnibus renewal legislation.)