Right now, humanity is reaching new heights of scientific understanding - and at the same time, it seems, is 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 rejects the cynical cliché that man is simply irrational - that he is an eternal troglodyte, ready to react to a lion in the grass with a heap of prejudice , blind spots, false conclusions and illusions. After all, we were the ones 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 only to the savanna of the Pleistocene era. He does an excellent job wherever scientific or technological issues are not being resolved, and people, in fact, rarely encounter anything 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, ideas about correlation and causation, as well as the best ways to clarify opinions and implement decisions made - how alone and collectively. These tools are not taught in typical educational programs and have never been taught clearly in one book before. Rationality is important. It helps us make good 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. Filled with Pinker's signature insight and humor, Rationality enlightens, inspires and encourages.