The essay sets out to investigate the various meanings the principle of laicism can assume and the evolution that it has undergone in recent years, in light of the latest instances of the intrusion of the 'sacred' in the public sphere. The ever increasingly more 'visible' presence in European society of persons belonging to cultures thoroughly imbued with religion seems to call into question the terms of the issue as understood heretofore, further calling into question the very distinction between the public and private sphere. In a lay State the possible solutions fluctuate between an attitude of 'secular' intransigence and greater openness with respect to the needs of a multicultural society. Among the various problems worthy of consideration, the essay focuses in particular on recent events having to do with the presence of religious symbols in public places, retracing the most significant moments thereof through an analysis of the jurisprudence of some of the European systems. The different conclusions that the author reaches concerning the crucifix and the Islamic veil are based on the assumption that the two matters in no sense can be equated, since one involves the necessary 'symbolic' neutrality of the State, while the other involves the free expression of religious beliefs.