Blockchains are bringing back pluralistic governance which was common in Medieval cities, with different economic systems overlayed on the same geography. Religious laws ran in parallel with secular law, and touched fundamental societal functions like finance and contracts. Generally, religious communities handled their own affairs and deferred to secular law for disputes between groups.

In Al-Andalus, aka Muslim-controlled Spain (roughly years 700 – 1500), Islamic law was the governing legal framework but Christians and Jews had their own internal systems as well. E.g., Jews governed their own marriages, dietary laws, and contract disputes but would be subject to criminal law, taxation, and general commercial law under the Islamic system.

While this system often led to conflicts over which laws had primacy, it also mitigated the economic downsides from bad laws. For example, Muslims and Christians had strict prohibitions on usury – in an effort to stop price gauging on loans they basically killed the market for credit. Jewish laws were more lax on lending, allowing credit creation that facilitated investment which ultimately benefited the entire economy. It wasn’t all rainbows and butterflies in Al-Andalus; religious groups would still experience persecution, special taxes specific to them, and would sometimes have their local law overruled arbitrarily and capriciously.

This kind of legal pluralism became less common as state power grew larger and more efficient, cities became more religiously homogenized (then secularized), the rise of nationalism (then globalism), and other factors. Paradoxically, new decentralized systems are rekindling legal pluralism by enabling self-governance of autonomous digital communities whose members operate within the framework of nation-state where they live.