I think you are both right to a large extent, and the distinction is whether you are focused on the easy cases, the hard cases, or some point in between. The r

I think you are both right to a large extent, and the distinction is whether you are focused on the easy cases, the hard cases, or some point in between. The repetitiveness in the common law is a massive feature and precedent does make the majority of cases quite predictable. And the outcomes of most cases are very principled - just not always with the hardest cases. The limitation, though, is in knowing whether the facts push a case in one direction or another. Quality lawyering makes a huge difference there, and it is the lawyer's skill that enables her to figure out how to interpret and shape the facts. As both of you have essentially noted, there are a potentially infinite number of fact patterns, but a finite set of legal rules, so any system must apply an existing law to a new set of facts from time to time. Whether that is viewed as applying an existing law or creating a new law is in the eye of the beholder, and legislators and judges disagree about that all the time. And whether that is a bug or a feature, is a deeper philosophical question that doesn't get at what an expert system can/will do. I think the only way you'll get a truly effective expert system for the law is if the software is integrated with the people making the law - the legislatures and the judges. I'm doubtful that will happen. In part, that is because I am doubtful that computer systems will ever be able to decide cases in a way that seems independent, fair and humane to the ones being judged. Short of that, my own startup (judicata.com) is working on mapping the legal genome so that we can identify the core legal rules, and how they are applied to different fact patterns. We think we can make big strides with legal technology in the coming years. It's not an Apollo level undertaking, but it's a pretty massive undertaking nonetheless. We're hoping that a systematic approach at understanding the law at a deep level of detail will allow us to make some of what has been discussed here a reality.