21 Organization of American States — OAS), tending to recognize the jus standi of the indigenous peoples (either before the conventional human rights organs of the United Nations, or before international human rights tribunals — the Inter-American Court or the European Court). In the context of the assertion of the international legal personality of the members of the indigenous communities, and of their practicing their international legal capacity, their rights to their ancestral lands have acquired special importance75. 59. It has been suggested that such endeavors have resulted from an ethical imperative, in order to acquit a historical debt the international community feels it owes the indigenous peoples, to make up for the injustices caused them at both the material and spiritual levels. More so than in the case of other minorities, awakening human conscience, universal legal conscience, to the need for enshrining the jus standi of the indigenous peoples takes the form of a true ethical imperative to acquit an historical social debt76. It is therefore not at all surprising that studies oriented towards the protection of the rights of the indigenous peoples are currently spawning in the most encouraging way77. 60. The breaches of the human rights of the indigenous peoples, and the reparations due them are to be found, in fact, at the roots of the historical process whereby the law of nations, jus gentium, was formed. The renowned Relecciones Teológicas by Francisco de Vitoria, specifically the famous De Indis — Relectio Prior (1538-1539), as well as the Tratados Doctrinales (1552-1553) by Bartolomé de las Casas, provide overwhelming evidence thereof, dating back to the 16th century. Both authors developed their solid arguments in defense of the rights of the indigenous peoples on the grounds provided by natural law. 61. In his renowned 16th century Relecciones, F. de Vitoria insisted on the need of faithfully observing the humanity principle (recalling comments by Cicero), to face the "many atrocities and cruelties well beyond all humanity "78. F. de Vitoria affirmed that indigenous people may not be prevented from “having true and lawful 75 . A. Meijknecht, Towards International Personality: The Position of Minorities and Indigenous Peoples in International Law, Antwerpen/Groningen, Intersentia-Hart, 2001, page 227, and cf. pages 134, 172, 175 and 213. 76 . Ibid., pages 228 and 232-233. 77 . Cf., inter alia, for example, R. Stavenhagen and D. Iturralde, Entre la Ley y la Costumbre - El Derecho Consuetudinario Indígena in América Latina, México, Instituto Indigenista Interamericano/IIDH, 1990, pages 15-388; R. Stavenhagen, Derecho Indígena y Derechos Humanos in América Latina, México, El Colegio de México/IIDH, 1988, pages 9-353; A.A. An-Na'im, Human Rights in Cross-Cultural Perspectives - A Quest for Consensus, Philadelphia, University of Pennsylvania Press, 1992, pages 189384; P. Thornberry, International Law and the Rights of Minorities, Oxford, Clarendon Press, 1992, pages 329-382; P. Thornberry, Indigenous Peoples and Human Rights, Manchester, University Press/Juris Publ., 2002, pages 1-429; P. Pérez-Sales, R.B. Herzfeld and T. Durán Pérez, Muerte and Desaparición Forzada in la Araucanía - Una Aproximación Étnica, Santiago de Chile, Ed. LOM/Universidad Católica de Temuco, 1988, pages 7-300; S.J. Anaya, Indigenous Peoples in International Law, 2a. ed., Oxford, University Press, 2004, pages 3-291; N. Rouland, S. Pierré-Caps and J. Poumarède, Direito das Minorias e dos Povos Autóctones, Brasilia, Edit. Universidad de Brasilia, 2004, pages 9-608; J. Castellino and N. Walsh (eds.), International Law and Indigenous Peoples, Leiden, Nijhoff, 2005, pages 89-116 and 249-267; S. Tristán Donoso, Régimen de Propiedad de Pueblos Indígenas, Panamá, Centro de Asistencia Legal Popular, 1993, pages 3-62; J.E.R. Ordóñez Cifuentes (coord.), Análisis Interdisciplinario de la Declaración Americana de los Derechos de los Pueblos Indígenas, México, UNAM, 2001, pages 1-160. 78 . Cf. F. de Vitoria, Relecciones del Estado, de los Indios y del Derecho de la Guerra, 2a. ed., México, Ed. Porrúa, 1985 [reed.], pages 95-96 and 98-99.