Liberal thought has made individual rational agents the basis of modern society. Yet, there is no such thing as a rational individual. Emotional reactions and heuristic shortcuts drive human decision-making. Humans also rarely think alone, but instead think together in groups. To Harari, individual humans have become more ignorant about the world. For example, a hunter gatherer in prehistory knew how to make their own clothes, how to hunt animals, and how to escape other predators. Today, we are dependent on the expertise of others, and fall victim to “the knowledge illusion,” (222) a term coined by two cognitive scientists. This term refers to the fact that humans think they know a lot, when they do not, because they treat collective knowledge as their own.

This human trait made sense in our evolutionary past, but it is massively problematic in the modern age. People remain ignorant of what is happening around them in a world that is becoming more and more complex. People do not acknowledge their ignorance. One solution to this issue is providing people with scientific-based information. Harari disagrees that this will help solve human ignorance. In fact, he believes that it could backfire because of the power of groupthink.