As history progressed the need to trade or receive new products changed. Instead of trading an item for an item and trying to guess what the values were, people now accounted their services to a common value item. When this common value item, money or coins, becomes universally accepted it can be used to trade. This is possible because you can trade the money you made for another good. Empires were a crucial part of making money standard. When all people live under the same rule it is easier for them to progress as a society. When laws, rules, value, and religion it makes it easier for them to relate to one another. Religion made it make sense for noblemen to justify conquering other nations with different views, this made the balance of religion and empires contradictory.
On page 241 Harari means that history is a constantly changing ideal. Sometimes the changes come from external sources, sometimes the changes come from internal disruptions. There is nothing natural or inevitable about the progression of societal structure. For the most part we can look at history to see how leaders came to power, how people were swayed into believing an idea, and how people interpreted religion to see how powers rose and fell.