... about a mighty ruler in ancient times, who summoned his philosophers and commanded them to provide him with a saying that would be true for all time. They went away and thought, and in due course came back with their answer. It was "Nothing is constant in this world but change." So civilisations rise and civilisations fall, because ultimately, the barbarians always win. It is always easier to destroy than to create. The barbarians then sample the good things that civilisation has provided, become civilised themselves, and are destroyed in their turn. And so it goes...