Text in English & Spanish. In the liberal world, the states claim to be neutral about religions but, at the same time, they grant them the right to a public presence. This book poses the question how the varied public manifestations of religion, including their argumentative ability, can be pacifically integrated into social and political life. The comeback of extreme ideologies, which refer -- justly or illicitly -- to their religious basis as protagonists in the public arena, makes us aware once again of the fact that religious tolerance must not go so far as to foster the suppression of public order: it has its limit where limitless freedom is used to destroy freedom for the sake of ideologies which are hostile to human dignity. The first part of the book deals with the question in terms which are conceptually open and which relate religion and politics with human action and history. The second part analyses how political thought has conceived the relationship between religion and politics by referring to certain milestones of philosophical-political thought.