The political opinions and behavior of the French cardinals, archbishops and bishops reflect the Catholic Church's adaptability in the post-conciliar era. For the first time, French bishops reflect individually and orally in front of a political scientist. With their spécifie symbolism, they speak about the évolution of the structures of their institution, of the social and political commitment of the members of the Church (bishops, priests, lay-Catholics), of social change, of relations with Marxism, of violence. In addition to interviews, the author had access to personal archives as well as those of the Church's hierarchy. She allows us to discover why and how bishops are still today major political, social and moral actors. The différences of function, génération and political climate, régional constraints as well as personal expérience lead to a pluralism of social and political options at any given time. But there is almost unanimity concerning two or three thèmes which touch on basic notions of faith. The deep estrangement of the bishops and the Church vis-à-vis politics is rooted in thèse thèmes.