In response to the environmental and health issues we are facing, and the unprecedented frequency of technological innovation, experts clash, contradict each other, or admit they have no answers. Controversies erupt much more frequently than new knowledge can be produced. In this age of uncertainty, when decision-making must often come before knowledge, we have to come up with new ways of thinking and acting together. Mapping controversies provides a framework for this. This pedagogical practice, fundamental in the social sciences, teaches us to examine the world without ever separating science, techniques, and society. It teaches us to take into account all perspectives and the context in which they are expressed, to conduct a close analysis of the ecosystem in which an object emerges, an invention or a phenomenon. To find our way through uncertainty, we must first immerse ourselves in complexity. This book shows us how, by relying on examples of contemporary controversies carefully chosen for their diversity and the wealth of their teaching.