Although today the foundation, not only constitutional, of the principle of justiciability of the administrative action is undisputed, and respected only where the protection is effective, there are still elements of immunity both with regard to the typology of the contested acts and the acts lodged to court. We can think about the political act, the administrative merit, the problem of defects so called formal, the protection against laws-provision, regulations, general administrative acts. More recently, the question of the protection of third parties has emerged, along with the massive phenomena of liberalization and simplification in progress. Therefore, the aim of the present essay is to provide a critical and evolutionary reading of such phenomena, proposing a development through three fundamental moments: the first, the oldest, which privileges the centrality of the administrative act; the second, more recent, which focuses on the person and his subjective juridical situations; the latest, most current, where these problems are captured through the complex phenomenon of "dialogue" between the courts.
Keywords: Justiciability; effectiveness; discretion; protection of third parties; political act; dialogue between the courts.