In a world where critical thinking and belief are scarce, rationality should be the foundation of all we do. He argues that everyone should be rational. Yet 75% of Americans believe at least one phenomenon that is not consistent with science's laws, such as psychic healing, extrasensory perception, and haunted homes. Even intellectual sophisticates claim that truth, objectivity, and reason are social constructs that justifies the privileges of dominant groups. Pinker asks, "Why is humanity losing its mind?" Scientists discovered a vaccine less than a year ago, but there was also an explosion of conspiracy theories. The pandemic was not a hoax or plot by global elites.
Pinker explains that reasoning is a brain mechanism that allows us to evaluate and argue arguments. Although no human being has ever achieved perfect rationality, we are convinced that objective truth exists and have created rules to help us get there. It is possible to cultivate the rules and make them normative. Pinker says it works. The ability to reach the Moon, eradicate smallpox, and invent computers is all thanks to Reason. It allows us to connect with objective truths. Reason tells us that there are some who are oppressed and others who have privileges, and that we should take steps to correct this injustice. We have thus developed the golden rule. This was not revealed by God, but is a product human evolution. It has been independently developed and rationally applied by all cultures.
Pinker argues that we are witnessing an alarming rise in irrationality. He explains that we live in a posttruth era and are witness to dangerous failures in critical thought and the groundeding of truth in evidence. Donald Trump, who was supported by 40% of Americans, predicted that Covid-19 would vanish like a miracle. He also disowned masks and social distance (even though he was stricken himself) and encouraged millions of Americans to do so. Fake news, along with belief in ghosts, the devil and spirits, is rampant.
Pinker reminds us, however, that we have made great strides. He says that life expectancy was not often over 30 years in the early 19th century. But, thanks to modern medicine, it now stands at 72.4. 90% of humanity lived in extreme poverty for most of human history. But that number has fallen to 9%. Although war is still a major issue, it has been drastically reduced. Most of the reduction was due to a rational argument that became viral and changed attitudes. Once widespread religious persecution has declined; homosexuality is almost no longer a crime; slavery is not completely extinct.
Pinker insists that all this is due to our ability to reason. It is, however, due to empathy. This allows for a wider, more focused approach to problem-solving and logical analysis.
Pinker is careful to distance himself from religion. However, at the end of the book his rational insights seem to have led to a more empathic sense of the underlying unity in all things. The equality of sentient beings is grounded in the logic irrelevance between me and you. This idea has been passed on through time by people who have a more empathic sense of the underlying unity of all things.
Pinker concludes the book with the following statement: We can only extract small amounts of happiness from a pitiless universe and be kind to others, even if we are flawed. It is not a flight from critical thinking but an essential part of human nature.