For long periods the High seem to be securely in power, but sooner or later there always comes a moment when they lose either their belief in themselves or their capacity to govern efficiently, or both. They are then overthrown by the Middle, who enlist the Low on their side by pretending to them that they are fighting for liberty and justice. As soon as they have reached their objective, the Middle thrust the Low back into their old position of servitude, and themselves become the High.