I have been thinking along this line for quite some years now.
"Equal justice under the law" as principle fundamental, it is only applicable to the law domain. There are domains with other rules superceding or competing with the law, such as the realtionship(s) between the creator(no necessaily the God) and men, man and himself, dilemma situations (e.g. trolley problem for antopilot car), etc. In ancient Chinese thoughts, there are 7 major domains in a 5-level system.
The society is not a single flat piece. People had been trying to analyze it by different models. I found Qian Mu's model so far had been the best (城市，鄉鎮，山林，江湖), which can be used to understand new laws' forming and concurrent law's implementing. An article in recent years observed the same. (How America Fractured Into Four Parts) I guess the author just collected and counted 4 without a full view as Qian Mu.
