Os observes that every great civilisation has a dynamism and a source of inspiration. But there comes a point where a civilisation loses touch with what made it great. From here, there are three broad options: you renew the inspiration, you replace the inspiration, or you decline. From the Parthenon in Athens to the Colosseum in Rome, you see that great civilisations have seen decline. We are at a watershed moment like this in the West.