I think you're right that any system can work if people believe in it, but there's only one system that people will believe in because it's natural.
It's not natural to be a slave. No non-domesticated animal prefers captivity or to be systematically deprived of it's resources.
Once resources start to be allocated via government guns, everyone will see that government guns are the real vis maior of the world and seek to control them.
What Stefan means by aggression is quite well defined. He means when discussion ends and someone picks up a weapon.
Humans have predatory instincts as well as cooperative instincts. They can go either way. The cooperative instincts however don't contradict. Everyone can indulge their natural desires without conflict except the ones to aggress on their fellows. That's natural law. So called because it's natural. Preying on your fellow man is natural, but it cannot be law because law must apply to everyone.
It can't be natural law to defend yourself and simultaneously attack others. Preying on your fellow human, thus can neither be a right nor law.
The uniformity of belief can be solved simply. By removing the only gun in the room, and allowing the gun to one special person, if that person wants it.
You, the individual.
When people are free as possible, then you will find the maximum uniformity of belief, if that's what you really want.
But I don't think you do.
I would like that. That's one reason why I want people to be free, to find out what that belief would be.
But usually when people talk about uniformity of belief, what they mean is imposed uniformity of their belief.
One thing we do know is that imposed uniformity has never worked and has caused more human suffering than anything else in the world.