An intergalatic civilisation needs cultures that evolve for long periods of time separately to be peaceful with each other as it’s likely possible for one solar system to extinguish other solar systems if it desires to do so in a way that can’t be traced back to the attacker.
It’s a core economic principle that actors that are more effective at using resources outcompete actors that are less effective no matter the amount of resources that are available.
An intergalatic civilisation needs cultures that evolve for long periods of time separately to be peaceful with each other as it’s likely possible for one solar system to extinguish other solar systems if it desires to do so in a way that can’t be traced back to the attacker.
It’s a core economic principle that actors that are more effective at using resources outcompete actors that are less effective no matter the amount of resources that are available.
Are you referring to multiple cultures that evolve alongside each other as part of the same civilization?
Your point about the economic principle is good.