Right now, humanity is reaching new heights of scientific understanding - and at the same time, it seems to be gradually going crazy. Why is a species that developed covid vaccines in less than a year mired in fake news, medical quackery and conspiracy theories? Pinker immediately abandons the cynical cliché that a person is simply irrational - that he is an eternal troglodyte, ready to react to a lion in the grass with a heap of prejudices, blind spots, false conclusions and illusions. After all, it was we who were able to discover the laws of nature, transform the planet, extend and enrich our own lives, and (not least) derive the rules of rationality. In fact, our minds are not adapted to the Pleistocene savanna alone. He does an excellent job wherever scientific or technological issues are not resolved, and people, in fact, rarely encounter something like this. But, alas, they do not know how to fully use the tools of knowledge that they themselves have developed over the past millennia: logic, critical thinking, probability theory, notions of correlation and causality, as well as the best ways to clarify opinions and implement decisions - how alone as well as collectively. These tools are not taught in typical educational programs, and they have never been taught in a single book intelligibly until now. Rationality is important. It helps us make the right choices both at the individual level and at the level of society as a whole and is ultimately the root cause of the growth of social justice and moral progress. Infused with Pinker's signature insight and humour, Rationality enlightens, inspires and encourages.