@cstross @AlexxKay @Nazani @angusm There wasn't a religious position that someone who looked like them could only be a slave…
There was a big tangle of social customs to economically integrate freedmen, come to that, which advantaged the former master and was normal and common.
Rome was an authoritarian horror; it wasn't as bad as a cult that wants to force God to end the world having control of nuclear weapons, and it didn't contain something as bad as the dominionist position on slavery.