19 Convention on the Law of Treaties (1986). Another participant in the Vienna Conference of 1968-1969 pondered that there are certain obligations - of protection of the human person - endowed with an "absolute character", which cannot be allowed to reduce, as "l'idée d'une régression définitive de la conscience humaine est difficile à accepter. En revanche il serait souhaitable que la pratique internationale se moralise dans tous les domaines et acquière ainsi, par la reconnaissance des États, un niveau croissant de valeur: il pourrait et il devrait y avoir normalement de nouvelles règles progressives. Sans qu'il soit nécessaire d'insister sur ce point, les racines profondes d'une telle conception rejoignent la tradition du droit naturel, rajeunie de nos jours par la conception du droit naturel à contenu progressif. En ce sens aussi, on pourrait soutenir que les règles impératives ont dépassé le stade coutumier pour atteindre un niveau plus stable qui est celui des principes généraux du droit international public"67. 60. Thus, the contemporary law of treaties itself, as attested by Article 60(5) of the 1969 and the 1986 Vienna Conventions, overcoming the precept of reciprocity in the implementation of treaties of a humanitarian character, reckons that the obligations enshrined therein are of ordre public, and may generate effects erga omnes. The overcoming of reciprocity in human rights protection has taken place amidst the constant search for an expansion of the ambit of protection (for the safeguard of an increasingly wider circle of individuals, in any circumstances), for achieving a higher degree of the protection due, and for the gradual strengthening of the mechanisms of supervision, in the defense of common superior values. 5. Concluding Observations. 61. Last but not least, attention should also be drawn to the interaction of human rights treaties in the process of interpretation. Given the multiplicity of those treaties, it comes as little or no surprise that the interpretation and application of certain provisions of a given human rights treaty have at times been resorted to as orientation for the interpretation of corresponding provisions of another - usually newer - human rights treaty. The practice of international supervisory organs - including under the two regional, European and Inter-American, systems of protection - affords several examples of such interpretative interaction68. 62. Moreover, given the possible concurrent interpretation of equivalent provisions of two or more human rights treaties, there is room for the search of the most favourable norm to the alleged victim. This test - primacy of the most favourable norm to the individual, - gathers express support in certain provisions of such human rights treaties such as Article 29(b) of the American Convention on Human Rights, and has found application in practice. 63. The essential motivation underlying the interpretation of human rights treaties has been, rather than to ensure the uniformity of international law in general and in all circumstances whatsoever, to respond effectively to the needs and imperatives of the 67 68 . P. Reuter, Introduction au droit des traités, 2nd. ed., Paris, PUF, 1985, p. 120. . Cf. A.A. Cançado Trindade, "Co-existence and Co-ordination of Mechanisms...", op. cit. supra n. (14), pp. 91-112, esp. pp. 101-103.