"We are repeatedly told these days that we are living in a new and frightening era of “post-truth”, and that lies and fictions are all around us. Examples are not hard to come by.

In fact, humans have always lived in the age of post-truth. Homo sapiens is a post-truth species, whose power depends on creating and believing fictions. Ever since the stone age, self-reinforcing myths have served to unite human collectives. Indeed, Homo sapiens conquered this planet thanks above all to the unique human ability to create and spread fictions.
We are the only mammals that can cooperate with numerous strangers because only we can invent fictional stories, spread them around, and convince millions of others to believe in them. As long as everybody believes in the same fictions, we all obey the same laws, and can thereby cooperate effectively.

So if you blame Facebook, Trump or Putin for ushering in a new and frightening era of post-truth, remind yourself that centuries ago millions of Christians locked themselves inside a self-reinforcing mythological bubble, never daring to question the factual veracity of the Bible, while millions of Muslims put their unquestioning faith in the Qur’an. For millennia, much of what passed for “news” and “facts” in human social networks were stories about miracles, angels, demons and witches. We have zero scientific evidence that Eve was tempted by the serpent, that the souls of all infidels burn in hell after they die, or that the creator of the universe doesn’t like it when a Brahmin marries an Untouchable – yet billions of people have believed in these stories for thousands of years. Some fake news lasts for ever.

When a thousand people believe some made-up story for one month, that’s fake news. When a billion people believe it for a thousand years, that’s a religion. But I am not denying the effectiveness or potential benevolence of religion. Just the opposite. For better or worse, fiction is among the most effective tools in humanity’s toolkit. By bringing people together, religious creeds make large-scale human cooperation possible. They inspire people to build hospitals, schools and bridges in addition to armies and prisons. Adam and Eve never existed, but Chartres Cathedral is still beautiful. Much of the Bible may be fictional, but it can still bring joy to billions and encourage humans to be compassionate, courageous and creative."

(in: Yuval Noah Harari: "Lessons for the 21st Century" )