Principi come Regulae: il caso Cappato, le liti strumentali e le ragioni costituzionali della regola Nemo audiatur allegans turpitudinem suam (con una postilla sul caso Trentini) (Parte I)
The essay argues that some of the much discussed outcomes of the Constitutional Court's decision on the 'Cappato case' can be explained by taking into account the strategic nature of the judicial proceeding from which it had originated; the point is developed by making special reference to the ancient regulae iuris and particularly to the regula Nemo audiatur allegans turpitudinem suam. The text is structured as follows: in Part I it is discussed the role of ancient maxims in legal knowledge and practice, and, referring mainly to the studies of, and on, Alessandro Giuliani, the reasons are argued in favour of a rediscovering of the maxims, as «constitutive principles of Law», in the constitutional interpretation; next, Nemo audiatur is called into play in order to explore the issue of lis ficta. In Part II the 'Cappato case' is analysed in detail, from the trial judgments to the Constitutional Court's ruling. Here it is shown how the regulae iuris offer insightful views for discussing both the theory of self-determination (and its fallacies) and some current uses of the human dignity concept. Conclusively, after a quick comparison with other recent decisions of the Constitutional Court, some additional considerations are made on why interpreting principles as regulae, and with regulae, could provide a degree of stability and effectiveness to constitutional principles, undermined instead by any instrumental conception of Law.