Juan Ginés de Sepulveda, Bartolomé de las Casas, and Francisco de Vitoria arguments pertaining to the settlement and colonization of the native people of America, while presented in different manors, are all the same. All three Spaniards believed that the barbarians had to accept the rule of the Spanish because the Spanish were mentally superior, and divine and natural laws gave the Spanish the right to conquer and enslave the native people of America.
The foundation for Spanish conquests was their interpretation of the bible. Ironically, it was the teachings of the bible they were all trying to bring to the newly found infidels. Sepulveda stated that the Spanish conquests were sanctioned in divine law itself, for it was written in the Book of Proverbs that "'He who is stupid will serve the wise man.'" In propositions one and two, Bartolomé de las Casas stated that he believed that Jesus Christ had the authority and the power of God himself over all men in the world, especially those who had never heard the tidings of Christ nor of His faith. Las Casas also stated in his second proposition that St. Peter and his successors(that being missionaries located in the New World) had the duty by the injunctions of God to teach the gospel and faith of Jesus Christ to all men throughout the world. What is interesting is that Las Casas thought that it was "unlikely that anyone [would] resist the preaching of the gospel and the Christian doctrine..." While being a bishop and a Dominican missionary in the New World, he had the task of spreading the holy faith, expanding the area covered by the teachings of the universal Church(that being the Christian religion), and the improvement of the natives' souls as his ultimate goal. As stated in proposition ten however, the Indians sovereignty and dignity and royal pre-eminence should not, in his belief disappear either in fact or in right. "The only exceptions are those infidels who maliciously obstruct the preaching of the gospel... ." In proposition eleven though, he continues by contradicting himself by saying that "He who persistently defends it[that being the preaching of the missionaries] will fall into formal heresy." Sepulveda also thought that if infidels rejected the rule of Christianity, it could be imposed upon them by force of arms. Sepulveda's justification for the use of force was, after all, justified according to natural law, and that just and natural noble people should rule over men who are not "superior". War against the barbarians, according to Sepulveda, was justified because of their paganism and also because of their abominable licentiousness. Sepulveda and Las Casas both thought that under no circumstances should the Indians be governed under their own rules. The Spaniards took the initiative by establishing several municipalities, which where governed by local nobles. The single fact alone that "no one individual owns anything,..." was enough for the Spaniards to establish a formal overseas administration for the infidels. Las Casas states "[we] are obliged by divine law to establish a government and administration over the native peoples of the Indies..." Sepulveda thought that those who were 'dim-witted' and mentally lazy, although they may be physically strong are by nature slaves, therefore they should serve and be lead by humane (superior)and cultured men. The fact that the Spaniards assumed that the natives were slaves(inferior) by nature is absolutely amazing. Francisco de Vitoria also thought that they were incapable of self-government and their weak minds left no choice but for them to be governed by those who had more knowledge, namely, the Spanish nobles. "The aborigines in question seem to be slaves by nature because of their incapability of self government... ...[therefore] it is permissible to seize their patrimony and enslave them..."
According to Juan Ginés de Sepulveda the "perfect should command and rule over the imperfect, the excellent over its opposite..." The Spaniards justified their conquests by arguing that they conquered and enslaved only those people who were unwilling to admit to Christian missionaries and therefore were rejecting divine law. As Sepulveda contemplated, the more perfect directs and dominates, and the less perfect obeys their commands. He stated that all of this derived from divine and natural law, both of which demanded that the perfect and most powerful rule over the imperfect and the weaker. He thought, along with several other people of the times, that it was just and only right to conform with the dictates of natural law, barbarians had no other course but to submit to the rule of the more cultured and humane princes and nations. The princes and nations of Spain held the beliefs that virtues and practical wisdom could destroy the barbarism of their nature and in turn educate the 'inferior' people to a more humane and virtuous life. "The Spanish Right of Conquest" gave them the 'right' to acquire slaves.
Sepulveda saw the infidels as people 'for the taking', and that they should be made to submit to the Spanish rule, and by force if necessary. The Dominicans, however, on the 'outside', preached that the infidels should "be preached peacefully, with love,... ...and affection,..." However, Las Casas does say that the infidels could "be punished by any judge... ...[if they] obstruct the preaching of the gospel and who refuse to desist after they have been sufficiently warned" It is clear then that Las Casas and Vitoria were not true 'friends of the Indians.' Both the Dominicans and Sepulveda were intent on achieving any gain possible for their country and themselves, and they didn't truly care what happened to the natives of America. Their achievements of converting the infidels further proved and backed that their justifications for imposing Christianity upon the natives was good, and just.