When you include common-law and look at the broader cycle, I'd argue the legal system is more like a JIT optimization rather than source code: We formalize and streamline lots of existing implicit social rules and shared expectations, things that exist-before and can operate-without any formal legal text... Just not as well.

In other words, the relationship is more like recipes versus cooking. People cooked foods first-- possibly many many times--and then formalized them later with documentation and rules to help make an outcome transferable or fast.

However, it would be a mistake to think that just because recipes are ubiquitous, they are a prerequisite for the process.