“The central objective of the environmental impact study is simple: to avoid that a project (work or activity), justifiable from an economic point of view or in relation to the immediate interests of its proponent, later proves to be harmful or catastrophic for the environment. The essentially preventive vocation of Environmental Law is fully valued, expressed in the well-known apotegma: prevention is better than cure (“mieux vaut prevenir que guérir”).“No other institute of environmental law better exemplifies this preventive direction than the EIA. It was exactly to foresee (and, from there, prevent) the damage, before its manifestation, that the EIA was created. Hence the need for the EIA to be prepared at the right time: before the beginning of the execution, or even of the preparatory acts, of the project. It is not for nothing that the Federal Constitution preferred to rename the institute, changing its name from “environmental impact assessment” to “prior environmental impact study”. (From the Authors)Hence the opportunity of this work, giving a broad view of the subject in its theoretical, practical and legislative aspect making it indispensable to all who have to deal with Environmental Law.”