122 Law and Morality Abroad (to ca. ad 1550)Sepúlveda and las Casas was the validity of the dilatatio principle. Las Casas
came to the contest more heavily armed, at least in quantitative terms. He
presented the panel with a 550- page treatise (Argumentum apologiae), which
appears to have been an early version of his major work, In Defense of the
Indians. It argued against the Spanish policies and in favor of a strategy of
winning natives over to the Christian religion exclusively by peaceful
means. On the question of the law applicable to the conquest of pagan peo-
ples, las Casas closely followed Vitoria. Like his pre de ces sor, he conceded
the existence of a number of just grounds for war, including forcible occupa-
tion of Christian lands, impeding the preaching of the truth faith, and wag-
ing aggressive war against Christians. But he was more explicit than Vitoria
had been in his emphatic denial, based on fi rsthand knowledge, that any of
these abominable acts had actually been committed by the Indians.
Las Casas’s stance on the two main issues— the natural- slavery question
and the validity of dilatatio to justify conquest— is of interest. On both, he
conceded the legal validity of the principles and rested his case on the facts
instead. Th at is, he accepted the Aristotelian thesis that some persons are
naturally suited for the condition of servitude. But he then vigorously ar-
gued that, as a matter of fact, the Indians of the New World did not fall into
that category.
He took a similar approach to dilatatio. Like Vitoria, he basically con-
ceded its validity. But he went on to argue that it could only serve as a justi-
fi cation for conquest if the acquisition of sovereignty was, in fact, truly nec-
essary to eff ectuate conversion. In his opinion, it was not necessary. On the
basis of his own extensive experience in the Americas, he insisted that con-
version could be brought about by more moderate means. Specifi cally, the
Spanish could establish missions on their own territories near the frontiers
with Indian states and then demonstrate, by example, the superiority of the
Christian life. Th e natives, he believed, could be relied on to recognize that
superiority and then to adopt the religion voluntarily— with no actual need
for Spanish po liti cal rule.
Sepúlveda advanced four arguments in support of the Spanish conquest
policy. Th e fi rst was that the various sins committed by the Indians (in-
cluding idolatry and sundry sins against nature) justifi ed war against
them. Second was the classic Aristotelian argument that the base nature of
the Indians made them naturally suitable for the role of servants to the