So if we keep Tradition and Authoritarianism, what fits alongside them? I think some sort of 'Liberty' civic makes sense, and maybe some variation of Equal Rights/Equality/Egalitarianism that doesn't create incompatibilities with Slavery, Caste System, etc. Not quite sure where to go after that. Doesn't feel like there are enough options for the Classical or Medieval eras.
What about Citizenship (or an analagous word), the idea that SOME people had a new legal status and that the system wasn't just the few despotic Rulers and everyone else? This existed alongside slavery (and caste system too?) for a long time, so it is Liberty of sorts but not for everyone. This could be the addition for those era's you think are lacking a good option.
I guess I'm still approaching this from the perspective that Legal is about creating categories of people so that then decisions can be made about how they must behave and be punished. This ties into rationales for those rules (tradition, gods etc) but I think it is fundamentally about deciding who has status and who doesn't as societies got so much bigger and more complex.
I still think Egalitarianism is a very old idea and more of societal value, rather than a legal foundation, while Equal Rights is a lot newer in the sort of Individual Rights way we think about it. If Equal Rights is kept on as a later civic in Legal, in this individualistic/western way that recognizes everyone--regardless of gender/ethnicity/etc--there is still a middle era civic missing. Something Legal that is similar to the problematic Feudalism civic lol. People have status of some kind, but not as equals, and alongside or post-slavery as a large institution.
Someone with more background on non-western civ's might know a Word/Concept that would fit those era's, some legal organization of a complex society that was around for a long time. What were the legal philosophies of the Ottoman Empire? It was around forever lol, or at least through those Era's where you feel like something might be missing from the civic's options.
Interesting ideas, lindsay40k. I too would really like to have some strong redistributive/egalitarian options later in the game, or to at least preserve them as viable options from the beginning. I always play Tropico as a commie lol, best way to deal with dissent.