Must religion be firmly restrained in private sphere or can it freely appears in public space? This historic debate is going on in confusion of speech and fundamental disagreement. The first position was the German social-democrats' on during congresses of Erfurt and Gotha, which was harshly ticked off by Marx. For Durkheim religion was a social fact and Marx Thought that all social fact must be bound by social critic. Fundamentally two ideas of << laicity >> are in contrast: emancipation of mind and freedom of consciousness. << Public >> and << private >> are very ambiguous words. A religious social fact can have a statute of public right (in France under concordat) or private fight (since Disestablishment of the Churh in 1905). In these second case the religious fact is subject to the common fight of public freedoms, first of all freedoms of worship and association.