9 22. In fact, the modalities of acceptance, by a State Party to the Convention, of the contentious jurisdiction of the Inter-American Court, are expressly stipulated in the aforementioned provisions; the formulation of the optional clause of compulsory jurisdiction of the Inter-American Court, in Article 62 of the American Convention, is not simply illustrative, but clearly precise. No State is obliged to accept an optional clause, as its own name indicates. Thus, a "reservation" to the optional clause of compulsory jurisdiction of the Inter-American Court of Article 62 of the American Convention would amount simply to the non-acceptance of that clause, what is foreseen in the Convention. But if a State Party decides to accept it, it ought to do so in the terms expressly stipulated in such clause. 23. According to Article 62(2) of the Convention, the acceptance, by a State Party, of the contentious jurisdiction of the Inter-American Court, can be made in four modalities, namely: a) unconditionally; b) on the condition of reciprocity; c) for a specified period; and d) for specific cases. Those, and only those, are the modalities of acceptance of the contentious jurisdiction of the Inter-American Court foreseen and authorized by Article 62(2) of the Convention, which does not authorize the States Parties to interpose any other conditions or restrictions (numerus clausus). 24. In my understanding, in this matter, it cannot be sustained that what is not prohibited, is permitted. This posture would amount to the traditional - and surpassed attitude of the laisser-faire, laisser-passer, proper to an international legal order fragmented by the voluntarist State subjectivism, which in the history of Law has ineluctably favoured the more powerful ones. Ubi societas, ibi jus... At this beginning of the XXIst century, in an international legal order wherein one seeks to affirm superior common values, among considerations of international ordre public, as in the domain of the International Law of Human Rights, it is precisely the opposite logic which ought to apply: what is not permitted, is prohibited. 25. If we are really prepared to extract the lessons of the evolution of International Law in a turbulent world throughout the XXth century, if we intend to keep in mind the endeavours of past generations to construct a more equitable and just world, if we believe that the same norms, principles and criteria ought to apply to all States (juridically equal despite factual disparities), and if we are really prepared to advance the ideals of the true international jurists who preceded us, - we cannot abide by an international practice which has been subservient to State voluntarism, which has betrayed the spirit and purpose of the optional clause of compulsory jurisdiction, - to the point of entirely denaturalizing it, - and which has led to the perpetuation of a world fragmented into State units which regard themselves as final arbiters of the extent of the contracted international obligations, at the same time that they do not seem truly to believe in what they have accepted: the international justice. 26. Not every practice consubstantiates into custom so as to conform general international law, as a given practice may not be in conformity with Law (ex injuria jus non oritur). Thus, it is not the function of the jurist simply to take note of the practice of States, but rather to say what the Law is. Since the classic work of H. Grotius in the XVIIth century, there is a whole trend of international law thinking which conceives all cases concerning the interpretation and application of the provisions of this Convention that are submitted to it, provided that the States Parties to the case recognize or have recognized such jurisdiction, whether by special declaration pursuant to the preceding paragraphs, or by a special agreement".