Religious freedom, Civil Constitution of the Clergy, but also refusal from the greater part of the Church : the Revolution inaugurates a conflict which will lead to the evolution of the concept of “laïcité” towards that of separation between Church and State, and will lead to the confusion between battle for “laïcité” and that against religion, even if the Concordat will maintain the secularisation brought about by the Revolution while reintegrating the Church within the nation. It is legitimate to suppose that writers and philosophers, among others the Idéologues, had a far from negligible role to play in terms of the popularisation of anticlerical themes and in favour of “laïcité”. Two conclusions can be drawn : the Revolution gave anticlericalism political weight and reality, and politicised the issue of the rejection or refusal of religion ; and it defined a condition for civil peace : the division in two spheres controlled by different and, if not opposed, ultimately complementary, principles.