Prevention is better than cure… It is difficult to dispute the relevance of this common-sense statement. However, when it comes to moving from words to deeds, difficulties arise. What health problems do we want to prevent? With what legitimacy? In what context? What are the levers on which to act concretely? What approaches have proved successful? How can cultural and social issues related to health be taken into account? How can we be effective while respecting people’s freedom? In 100 words, this book offers a complete vision of the issues, policies, and practices to enable everyone to understand, to take part in the debate, and — why not? — to contribute to making prevention one of the pillars of living together.