In his presentation of Michael Walzer's method Gianfrancesco Zanetti begins from the personal memory of reading "Exodus and Revolution" to describe this method not only as destructive but also as a positive effort. The "rootedness" of the philosopher's interpretative approach takes him neither to relativistic or conservative solutions nor to a universalism of a «covering law». His moral realism describes a concrete approach to the problems to elaborate workable solutions. Walzer's attention to pluralism and to the connections between religion and politics allows him to discuss every form of one-sidedness, dogmatism and mainstream thinking. Drawing the line, the boundaries become therefore of crucial importance to realize a more just society, even at the cost of having dirty hands.