Harari reminds the reader that inventing fictional ideas helps people cooperate in large groups (because people can trust strangers who believe in the same ideas and follow the same rules, even they don’t know each other). Harari reminds the reader that such ideas are often positioned
as if they’re inherent, natural, or biological facts (e.g., the imagined idea that one gender or race is superior to another). In fact, they’re just made up—meaning they can be changed, which is how cultures evolve.