22 ownership, be it private, public or political”, and added that the essential purpose of Law is “the dignity of the individual as a rational being. Men come to be moral persons and subjects able to of have rights and obligations due to their rationality, for, by using their rational capacity and their consequent freedom, they acquire control over their own actions and are also free to choose their own destiny (…). Rational capacity is, therefore, at the root of the formal grounds making man capable of acquiring dominion and rights.”79 Eloquent in his defense of natural law80, F. de Vitoria contended that natural law conforms to recta ratio, being therefore derived from reason and not from will and aimed at achieving common good above all81. As I pointed out in a recent book, even long before F. Vitoria, recta ratio was very well apprehended into a notion by Plato and Aristotle and later, unsurpassedly, by Cicero and Tomás Aquinas, to be right afterwards duly placed at the foundations of jus gentium, precisely by F. Vitoria, besides F. Suárez and H. Grotius82. In effect, the common good imperative is deeply rooted in the thinking of Francisco de Vitoria, for whom it constitutes a "superior purpose" of the civitas maxima, and the very evolution of the law of nations shall be the "collective work of the human community " as a whole83. 62. 63. On his part, Bartolomé de las Casas, in his Doctrinal Treatises, written in the same 16th century, denounced the “depopulation of over two thousand leagues of land”, carried out with “cruelty and inhumanity” by “the Spanish in the Indies”, brought about “the perdition and death of an infinite number of peoples,”84 in addition to the "destruction of their State and of all of the well-being of that world, and against the right of private individuals, and against natural law, taking away and robbing and tyrannizing not only property, but also the freedom, the lives and the people to give them to 85 others.” According to the teachings of B. de las Casas, no person can lawfully dispossess others, do others such wrong, thus infringing natural law and the law of nations.86 This prompted the author to make a distinction between the primary law 64. 79 . T. Urdanoz (ed.), Obras de Francisco de Vitoria - Relecciones Teológicas (Francisco de Vitoria’s Works, Theological Lectures), Madrid, BAC, 1960, page 521, and cf. page 552. 80 . Cf. ibid., pages 564 and 675. 81 . F. de Vitoria, La Ley [De Lege - Commentarium in Primam Secundae, 1533-1534], Madrid, Tecnos, 1995 [reed.], pages 5, 23 and 77. On recta ratio as the ultimate grounds of jus gentium, cf. A.A. Cançado Trindade, A Humanização do Direito Internacional, Belo Horizonte/Brasil, Edit. Del Rey, 2006, pages 3-29. 82 . A.A. Cançado Trindade, A Humanização do Direito Internacional, Belo Horizonte/Brasil, Edit. Del Rey, 2006, pages 3-29. 83 . Yves de la Brière, "Introduction", in Vitoria et Suarez - Contribution des théologiens au Droit international moderne, Paris, Pédone, 1939, pages 5 and 10. 84 . B. de las Casas, Tratados (Treatises), Volume I, Mexico, Fondo de Cultura Económica, 1997 [reed.], page 219 85. B. de las Casas, Tratados (Treatises), Volume II, Mexico, Fondo de Cultura Económica, 1997 [reed.], page 761. 86. Ibid., Volume II, page 1249.