Terry Pratchett has a lot of good aphorisms, but one that stuck with me is some etymology from a cop and a Machiavellian dictator:
> "It's all for the good of the city, sir. Do you know where the word 'policeman' comes from? It means 'man of the city', sir. From the old word polis."
> ...
> "You're a man interested in words, captain. I'd just invite you to consider something your predecessor never fully grasped."
> "Sir?"
> "Have you ever wondered where the word 'politician' comes from?" Said the Patrician.
These roles have a very specific purpose, and that purpose is service. They've veered sharply away from it, but that is still their job. Also, I think in real life the root is 'politia' or 'politika' or something, but the definition is similar.
And another word from that book: 'polite' apparently came from 'behavior befitting someone living in a city.' I guess social norms maybe became more important with the density?