Abstract

Within the article, the positions of Costantino Mortati on the nature of trade unions are related to the reasons leading to the introduction of the principle of horizontal subsidiarity in the Constitution. In this theoretical-legal framework, the specificity of the trade unions, which determined the peculiar evolution of collective bargaining in Italy, is read within the more general ambivalence of social formations. By combining the autonomy of private entities with the representation of interests and requests of a collective nature, they have constituted an excess over the dichotomous architecture of law, based on the irreducibility of the public and private sectors. The principle of horizontal subsidiarity, recognizing the ability of individuals and associates to achieve general interest, has opened up a new space for institutional experimentation, laying the foundations for a “pluralizationµ of the legal system