This article explores, in the French context, an aspect of what Terence McLaughlin (1991) has described in an unpublished paper as the ‘dilemma of substantiality’ faced by any school system endeavouring to promote neutrality. In France, in order that the public or common school be genuinely open to all students, not only is the wearing of conspicuous religious symbols forbidden but so too is any direct teaching of religion. The cultural consequences resulting from this prohibition have led to the mandating (...) of cross-curricular teaching about religion. This article aims to show that the civic principles (la laïcité) on which this teaching is based pose in an acute and problematic form the ‘dilemma of substantiality’. (shrink)