This book presents scientific activity, at first as it functions on its own, and then in relation to other learned activities. The author argues that science has endowed us with the sense that we are free agents and that we cannot be easily fooled by the appearance of things in the world.
Yves Quéré begins by describing what science does. First of all scientists “name” things and so make us see more attentively what lies around us. Then science orders the world, enabling us to ward off natural phenomena that may seem threatening. Finally, it “describes” (by asking “How?”) and “explains” (by asking “Why?”), often by creating mathematical models. But as it develops a system of knowledge, it also creates ignorance; science can thus be regarded as an endless undertaking.
Science is taught in schools, and the author reviews the course used in French schools known as La main à la pâte, which aims to give children a hands-on approach to science. The author believes that the teaching of science should be experienced as a “return to the real world”. Learners should observe, imagine, be amazed, experiment, discuss and express themselves. Science educates, for it teaches “virtues” (in the classical sense of the word), showing us that we should respect the truth, be modest, practise hygiene and rigour, use our imaginations, uphold freedom of thought, scrutinise our doubts, and always use clear precise language.
The author has not ignored the ambivalent feelings raised by science: fear and admiration; incomprehension and deference. He also examines some of the contradictions inherent in science itself: secrecy and democracy, selflessness and thirst for power, progress and risk-taking. Quéré proposes a professional code of ethics for scientific research.
The second part of the book examines relations between science and each of the following: history of science, ancient languages, art and religion, human rights, and politics.
In the final chapter, all the subjects that have been previously studied are minutely illustrated with Penrose patterns.

Yves Quéré, a physicist and professor emeritus at the l’École polytechnique, in Paris, is a member of the Academy of Sciences.