"Experience suggests that if men cannot struggle on behalf of a just cause because that just cause was victorious in an earlier generation, then they will struggle against the just cause. They will struggle for the sake of struggle. They will struggle, in other words, out of a certain boredom: for they cannot imagine living in a world without struggle. And if the greater part of the world in which they live is characterized by peaceful and prosperous liberal democracy, then they will struggle against that peace and prosperity, and against democracy."