"Capitalists and communists disagreeing about the nature of the world in the twentieth century was a global collision of just two consensus realities. Back then, consensus realities were a read-only game for most people. It was expensive to create one. You had to build impressive buildings, give speeches about values, own newspapers, hire goons to beat up opponents, declare manifestos, and so forth. We are now entering a read/write era of consensus realities. Our ability to disagree about the nature of our world, at an extremely fine-grained and visceral level, is about to explode."