In this book the tragic case is characterized as a problem that only emerges with post-positivism or neo-constitutionalism; and from the standard theory of legal argumentation, which identifies it as a limit to legal rationality in that the collision of principles in which it arises cannot be resolved under the aegis of proportionality weighting, three elements are proposed that give it conceptual identity in the field of legal argumentation: (i) superposition of the factual assumptions of the principles that collide in the specific case, (ii) failure to satisfy the minimum requirements of such principles, to a greater or lesser extent measured through the possible decision courses, and (iii) the absolutization of the principle that prevails in the decision, which in turn implies the total affectation of the opposite principle. These elements make it possible to identify the tragedy in a legal case, which can even occur outside the judicial sphere. It also relies on the rule of least constitutional damage and conciliation, as hermeneutical parameters that should guide the resolution of the tragic case.