A couple of broad themes emerge in Harari's book: How did humans develop the capability to cooperate in large groups of strangers? And his answer: the social constructs, which he usually calls myths, that they develop. He exhibits and discusses two, each of far reaching historical and practical importance: The Code of Hammurabi (1776 BC), and the Declaration of Independence (1776).
He exhibits some samples:
(209) If a superior man strikes a woman of superior class and thereby causes her to miscarry her fetus, he shall weigh and deliver ten shekels of silver for her fetus.
(210) If that woman shall die, they shall kill his daughter.
He has some problems with the Declaration too.
'Cooperation' sounds very altruistic, but it is not always voluntary and seldom egalitarian. Most human cooperation networks have been geared towards oppression and exploitation. The peasants paid for the burgeoning cooperation networks with their precious food surpluses, despairing when the tax collector wiped out an entire year of hard labor with a single stroke of his imperial pen.
A subsidiary theme is how human life changed as humans 'progressed'. Agriculture compressed human spatial horizons, often to a single village, field and hut, but expanded his time horizons. Hunter gatherers don't worry much about the future because there isn't anything they can do about it. Farming is the opposite. Seeds need to be planted when they need to be planted and surpluses need to be stored. A hundred eventualities need to be prepared for.
Sapiens: A Brief History of Humankind by Yuval Noah Harari