In this post I'd like to focus on what Harari has to say concerning polytheism. He first notes (correctly) that polytheists, although they believe in many gods, nonetheless generally believe in a single, unified power behind the gods. It is the nature of this supreme power that is the essence of polytheism:
The fundamental insight of polytheism, which distinguishes it from monotheism, is that the supreme power governing the world is devoid of interest and biases, and therefore it is unconcerned with the mundane desires, cares and worries of humans. It's pointless to ask this power for victory in war, for health or for rain, because from its all-encompassing vantage point, it makes no difference whether a particular kingdom wins or loses, whether a particular city prospers or withers, whether a particular person recuperates or dies. The Greeks did not waste any sacrifices on Fate, and the Hindus built no temples to Atman.
The only reason to approach the supreme power of the universe would be to renounce all desires and embrace the bad along with the good - to embrace even defeat, poverty, sickness and death. Thus some Hindus, known as Sadhus or Sannyasis, devote their lives to uniting with Atman, thereby achieving enlightenment. They strive to see the world from the viewpoint of this fundamental principle, to realize that from its eternal perspective all mundane desires and fears are meaningless and ephemeral phenomena.
Most Hindus, however, are not Sadhus. They are sunk deep in the morass of mundane concerns, where Atman is not much help. For assistance in such matters, Hindus approach the gods with their partial powers. Precisely because their powers are partial rather than all-encompassing, gods such as Ganesha, Lakshmi and Saraswati have interests and biases. Humans can therefore make deals with these partial powers and rely on their help in order to win wars and recuperate from illness. There are necessarily many of these smaller powers, since once you start dividing up the all-encompassing power of a supreme principle, you'll inevitably end up with more than one deity. Hence the plurality of gods.
The insight of polytheism is conducive to far-reaching religious tolerance. Since polytheists believe, on the one hand, in one supreme and completely disinterested power, and on the other hand in many partial and biased powers, there is no difficulty for the devotees of one god to accept the existence and efficacy of other gods. Polytheism is inherently open-minded, and rarely persecutes 'heretics' and 'infidels'.
The first thing to say about this treatment is that it is entirely reasonable; in fact, we might go so far as to say that what has been described is the 'natural' religion of mankind - the way man would almost inevitably think about religion if left to his own devices. And, indeed, as Harari points out, it is the way most men have thought about religion in most times and places, from the ancient Egyptians to the Chinese, to the Indians, to the Aztecs and the Romans.
Jews and Christians do not disagree with the logic of polytheism, and probably would have followed the natural inclinations and reasoning of everyone else - except that the polytheist position contains a small hole in it: "The supreme power governing the world is devoid of interest and biases, and therefore it is unconcerned with the mundane desires, cares and worries of humans." Suppose that the supreme power, although devoid of interests and biases, nonetheless takes an interest in men? An interest men never asked for, expected, or even wanted, but that nonetheless occurs? Suppose this supreme power keeps pestering man even though we'd rather be left alone? That story, the story of the supreme power pestering an obscure ancient people into a relationship with Him, for reasons mysterious to us, is the real story of the Old Testament.
Suppose further that the supreme power not only pesters man from afar, but does the unthinkable and takes on the form of man and appears among us as a man among men - not because of any interest or biases He might have, but because He loves us. In other words, the supreme power pestered the ancient Jews and appeared in the form of Christ for our sakes, not His own.
This is an idea "unnatural" to man, and its unnaturalness is one reason I believe it. The fact that the supreme power, Atman or Jehovah or Fate, would act purely in our interest rather than His own is a thought that simply doesn't occur to us. That He would appear among us, voluntarily suffer, die and be buried by us, is also another idea that wouldn't occur to us. The only way the idea entered into human history is because it happened.
Harari doesn't get this in his explanation for the origin of Christianity:
The big breakthrough came with Christianity. This faith began as an esoteric Jewish sect that sought to convince Jews that Jesus of Nazareth was their long-awaited messiah. However, one of the sect's first leaders, Paul of Tarsus, reasoned that if the supreme power of the universe has interest and biases, and if He had bothered to incarnate Himself in the flesh and to die on the cross for the salvation of humankind, then this is something everyone should hear about, not just the Jews. It was thus necessary to spread the good word - the gospel - about Jesus throughout the world.But we've already learned that the supreme power of the universe doesn't have interests and biases. At least this is what people always and everywhere naturally think. And why would Paul believe that this supreme power would, even if he did have interests and biases, humiliate himself by becoming a man and suffering and dying at our hands? That conditional is the crux of history - but Harari glides over it and onto the unexceptional point that if in fact one believes this happened, it's something the rest of humanity should hear about. There is a glimmer of insight at the end of the quoted text that Christianity is not fundamentally a view of the world, or a deduction based on the nature of the supreme power or the possibility that lesser deities might be open to influence, but news, i.e. an unexpected irruption of the supreme power into history. This news spreads within decades across the Roman Empire and within a few centuries captures the hearts and minds of Western Civilization, a massive upending of history that Harari can only remark is one of the "strangest twists" in history. It is indeed the strangest twist in history; perhaps because in it there was more going on than mere history?
Finally, Harari seems to embrace the contemporary conviction that tolerance is the highest virtue, and prefers polytheists like the Aztecs or Hindus to intolerant monotheists like Jews and Christians. Tolerance seems admirable in the abstract, but perhaps not so much up close when we examine what polytheistic tolerance actually involves. As Harari notes, "In the Aztec Empire, subject peoples were obliged to build a temple for Huitzilopochtli, but these temples were built alongside those of local gods, rather than in their stead." He leaves unsaid that the subject peoples were also obliged to regularly send to the Aztec capital not only food and other goods, but also captives destined to suffer ritual human sacrifice. One reason Cortez was able to conquer the mighty Aztec Empire with a few hundred conquistadors is that the subject peoples were more than happy to join him in overthrowing the Aztecs, their "tolerance" notwithstanding. And in India, polytheists tolerated suttee (the burning of widows on the pyre of their husbands) for centuries until it was finally outlawed by the intolerant British.
The tolerant polytheist tolerates everything, the good and the bad. And nothing ever really changes, year after year, decade after decade, century after century. The intolerant monotheist, in the name of the supreme power, decisively intervenes in history in response to the supreme power's own decisive intervention in history: The result is the uniquely dynamic history of Western Civilization since the time of Christ.