If the law is getting too complex for humans to handle, the solution is not to create supercomputers that help us. The solution should be to simplify the law.
Reforming law to be machine readable might eventually provide a litmus test to prevent the passage of bad laws. It could also provide a way to flag prior law that is invalidated by a new law.
Murder occurs when a person, of sound memory and discretion, unlawfully kills a person, with malice aforethought.
Seems simple the there are hundreds of cases that tell you what exactly the limits of these elements are. Is being drunk sound mind? What constitutes malice aforethought.
The law is complicated because reality is complicated.
The civil law system keeps it a bit less complicated by not using precedent from old cases. But that means the application in your case is harder to predict. It is your judge making the gut call instead of a history of judges.
In practice, a lot of the quirky, wonky code is there to fix an actual bug that was encountered, and taking it out re-introduces the bug.
How do we know eliminating some of the complexities of current laws won't re-introduce some of the problems those complexities were trying to solve?
The other side of that coin is: are the bad outcomes produced by the current codebase bad enough that we will replace them and accept the risk of re-introducing the other bugs?
Alternatively, the entire codebase is in English (+/-) so one could document the bugs that changes are attempting to address.
The problem is that much (although admittedly not all) of the complexity in the law is a result of attempts to clarify and provide consistency to the nuance and obscure edge cases that occur in real life. Removing that nuance from codified law results in it being even more down to a judge's individual interpretation than it is today, meaning individuals would be even less clear on where they stand than they do now.
If a computer could accurately interpret the law, and that computer was freely available to everyone, I think we'd all be in a far better position.
Lawyers are often behind movements to simplify the law. The problem is that efforts to simplify the law often lead to (what some substantial group feels are) substantially negative impacts given the complexity of the reality the law is meant to deal with.
Simplifying often sounds better in the abstract than in concrete terms.
The problem of common sense is that everybody has his own, you can't build rules on sand and that's what "common sense" is.
For one person it's common sense to snip bits of genital organs from infants, for the next it's common sense to pray 5 times a day, for yet an other one it's common sense to flog your children to bleeding, outright own other human beings or threaten those who don't agree with you with maiming or death. You will find people telling you it's common sense to have live grenades on your coffee tables, plant anti-personnel mines in your garden, answer a door-knock by shooting through the door or walk around with enough weaponry to take over a small country.
Relying on "common sense" is relying on hyperlocal groupthink, it's not even workable in tribal societies, it's barely workable within a small family.
Often by the time something reaches the court, there is no possible outcome that provides justice for all, and the court instead has to determine which of the parties to screw the least.
I think this is demonstrated by Coase's "The Problem of Social Cost" [1]
> Because in the real world there are costs of bargaining and information gathering, legal rules are justified to the extent of their ability to allocate rights to the most efficient right-bearer.
* Jury instruction have been rewritten using the minimum number of terms that jurors won't already know.
* Legal decisions are written to be more readable to contemporary laypeople. (At least they seem that way to me -- it's a little hard to tell given the change in writing styles generally.)
* Uniform legal codes have refactored the law to make it more consistent state-to-state, and to remove complexity when for example two causes of action could be reduced to one.
* Property law (which probably moves more slowly than others) has moved away from centuries-old "magic phrases" that could break inexpertly-written deeds.
But all of this is basically syntax. It makes the system easier to learn, but doesn't reduce the fundamental complexity of the model.
And you can't reduce that complexity much, if you want a system that is "fair" and "just" at scale. "Fair" meaning that it treats like cases alike, and different cases differently. "Just" meaning that it mostly comes to what most people consider the right outcome in individual cases.
The scale here is hundreds of millions of people over hundreds of years, any two (or more) of whom can interact in a way they want the law to settle. Treating all of those cases "fairly" means at least one of: already having a rule that roughly guides the outcome for a given dispute (statutes and regulations), or taking into account the decisions other people came to in similar cases in the past (caselaw). Treating the cases "justly" means those rules and analogies have to be fine-grained -- if one of the parties points out a special circumstance in their case, and most people would feel that it should change the outcome, then it needs to be taken into account for the system to be just.
So law is complex because the potential interactions between hundreds of millions of unique individuals are complex.
You might want to reduce complexity by reducing the reach of the law, but I don't think you can reduce it that far and still have a recognizable society. For example, many libertarians would prefer a system with greatly reduced criminal law and commercial regulation -- but where the government still enforces contract and property law in a way that is predictable and fair. The system for fairly, justly, reliably, predictably enforcing the contracts entered by hundreds of millions of people over hundreds of years is going to be complex -- the same kind of complexity we have now.
Obviously the situation could be better or worse -- the stuff I listed at the top are small examples of how it's gotten better. Making the system (say) half as complex would be great. But it wouldn't fundamentally change the problem space, or make tools like Watson unhelpful for solving it.