Book excerpt: The papers assembled in this volume should enable readers to understand what too many people today insistently misperceive. Environmental protection is not just a "special interest". It is an essential task for everyone. This book brings together texts by social scientists from the United States, France and Spain. Their common frame of reference is the dialectic between experts and activists in socio-environmental movements, as well as the concern about changes, both cognitive and political, arising in that context.