Sustainable societies & civilisation
Low tech, natural societies have shown their ability to last over time.
Tribal or low density settlements seem to last the longest.
Human empires, with their large cities, seem to rise and fall, giving birth to advanced technologies that sustain them for a while, before they finally collapse into near nothingness, for reasons not always known.
From this arises the question: can civil high density living proceed unhindered by a built in balancing force that literally smashes the society to pieces?