The chapter generally looks into the memory system of human beings. The memory of the Homo sapiens stores a lot of information, and thus the sapiens must have stored a lot of information during agricultural revolution. Prof. Harari claims that empires which developed in the agricultural societies had a lot of information. The empires had to record taxes, transactions, merchant vessels, calendars of victories and festivals and inventories of military supplies. Funnily, Prof. Harari writes that for millions of years man preferred storing information in their brain. Unfortunately, it was difficult for humans to store all the information of the empire for some key reasons. The reasons mankind could not store all the information in the brains included, limited capacity, brains die following the death of humans and  the human memory could only store certain information.

In a nutshell, Prof. Harari in this chapter was interested in understanding the storage of information in the past. As he notes “Empires generate huge amounts of information “(89).  This information had to be stored. As man evolved, at first the information could be stored in the memory and then when an individual who had the information died, they could definitely die with the information. The limitation of the mental capacity, necessitated the group of people called, Sumerians to develop information strange system. The Sumerians lived in southern Mesopotamia and its geniuses invented a system that enabled them to store and process huge amounts of information outside the memory. The invention made by Sumerians was writing, and through this invention the information could be documents and usually stored as mathematical data. The mathematical scripts made it easier to store data as well as empires and kingdoms were able to store information on harvests or transactions through writing. This replaced the dependence on human brains for information storage.