Starting from a re-reading of the Constitution and the Fordist-Bismarckian ethos and foundations of Italian welfare, the author draws attention to some aspects being affected by the crisis and by change. In particular he identifies in some sectors of welfare a trend – in line with the principles of the Constitution – towards a universalist vision founded on the principle of social citizenship that is making the system more «mixed» than its original «pure» employment type. In the light of this the article describes the development of ordinary legislation in the early decades of the Republic and the changes in labour and social law; it then focuses on the process of change, which has always been fairly continuous, but in the 1970s and 1980s it set off a process of social and institutional modernisation and a long season of reforms that in the last two decades has developed in a new direction, designed to base intervention on the principle of social citizenship. However, this development has many ambiguities and contradictions, and cannot be seen as complete, above all in a country that still has to come to terms with the project of modernity and fully acquire, culturally and politically, the secular and republican ideals of the universal rights of citizenship. The essay’s contribution is to show the importance of the framework of fundamental principles and social rights provided by its Constitution, showing how it constitutes an indispensable basis for a social reform of this importance.