The concept of secularisation is far from unanimous and uncontested. In the current debate on the theme, three aspects would seem to stand out: that of differentiation between the secular sphere and the sphere of religious institutions and norms, that of the decline of the religious as belief and practice, and that of the privatisation of the religious. An analysis of the debate and of the great diversity of situations regarding the presence of religion in modern life points to the need for a complex analysis. The same applies to modernity, or rather various modernities, as would seem to be more applicable nowadays. This text constitutes a reflection on the viability of applying certain theories on secularisation to the Portuguese reality, ...