Small brain: Society was perfect at some point in the past.
Normal brain: No existing human society is perfect, but <ideology> will be.
Big brain: No human society will ever be perfect, but we can strive for improvement.
Galaxy brain: A functional society is as good as humans can ever hope to achieve.
Universe brain: Every possible human social structure is unstable. ALL human societies will eventually degenerate and collapse into chaos and anarchy. It's just a question of how long it takes.