Look at the bigger picture, though, the transition from many small cultures to a few large cultures and finally to a single society was probably an inevitable result of the dynamics of human history.

不可否認(rèn)歷史里的政治和文化理念上的分分合合，總是一個充滿張力的一體隘膘，黏久了必定會分出differences，分久了也一定會出現(xiàn)新的融合方式。

What is the difference between describing "how" and explaining"why"?To describe"how" means to reconstruct the series of specific events that led from one point to another. To explain "why"means to find causal connections that account for the occurrence of this particular series of events to the exclusion of all others.

This conclusion disappoints many people, who prefer history to be deterministic. Determinism is appealing because it implies that our world and our beliefs are a natural and inevitable product of history. It is natural and inevitable that we live in nation states, organise our economy along capitalist principles, and fervently believe in human rights. To acknowledge that history is not deterministic is to acknowledge that it is just a coincidence that most people today believe in nationalism, capitalism and human rights.

So why study history? Unlike physics or economics, history is not a means for making accurate predictions. We study history not to know the future but to widen our horizons, to understand that our present situation is neither natural nor inevitable, and that we consequently have many more possibilities before us than we imagine.

We cannot explain choices that history makes, but we can say something very important about them; history's choices are not made for the benefit of humans.

A culture idea- such as belief in Christian heaven above the clouds or Communist paradise here on earth- can compel a human to dedicate his or her life to spreading that idea, even at the price of death. The human dies, but the idea spreads.…Rather, culture are mental paradise that emerge accidentally, and thereafter take advantage of all people infected by them.

At the end of the process, the balance of power may remain much as it was, but meanwhile billions of dollars that could have been invested in education or health are spent on weapons. Yet the arms race dynamic is hard to resist. "Arms racing" is a pattern of behaviour that spreads itself like a virus from one country to another, harming everyone, but benefiting itself, under the evolutionary criteria of survival and reproduction.

Around AD1500, history made its most momentous choice, changing not only the fate of.humankind, but arguably the fate of all life on earth. We call it the Science Revolution.