The theory challenge and response basically means humans make an extra effort when a challenge is set in front of them. Let’s say the rise in population and as the society proceeds, problems occur. Such as the conflict over division of labor, or the competition for dominance, or perhaps who should get the extra food that’s left over. So the whole society makes progresses as each individual tried to respond to that challenge, causing civilization to take place. The material explanation: individuals could not always make what they need, due to their geographical or ability limits. So they needed to work as a whole, under a ruler. Non-material explanation: the same religious interests unified humans, making religious activities as a group possible to be organized.

作者：本人已死。 IR