Harari's key claim regarding the Agricultural Revolution is that while it promoted population growth for Sapiens and co-evolving species like wheat and cows, it made the lives of most individuals (and animals) worse than they had been when Sapiens were mostly hunter-gatherers, since their diet and daily lives became significantly less varied. Humans' violent treatment of other animals is a theme that runs throughout the book.
In discussing the unification of humankind, Harari argues that over its history, the trend for Sapiens has increasingly been towards political and economic interdependence. For centuries, the majority of humans lived in empires, and capitalist
globalization is effectively producing one, global empire. Harari argues that money, empires, and
universal religions are the principal drivers of this process.
Harari sees the Scientific Revolution as founded on innovation in European thought, whereby elites became willing to admit to, and hence to try to remedy, their
ignorance. He sees this as one driver of early modern European imperialism and of the current convergence of human cultures. Harari also emphasises the lack of research into the history of
happiness, positing that people today are not significantly happier than in past eras.
[5] He concludes by considering how modern technology may soon end the species as we know it, as it ushers in
genetic engineering,
immortality, and
non-organic life. Humans have, in Harari's chosen
metaphor, become
gods: they can create species.