116 Law and Morality Abroad (to ca. ad 1550)expeditions of conquest must be accompanied by two clerics, and that their
prior written consent was a prerequisite to the employment of armed force.
If war was waged contrary to this policy, then the expedition contract was to
be revoked. Remarkably, the constraints imposed by the Spanish govern-
ment sometimes did have eff ects on the actual conduct of the conquerors.
When the audiencia of Guatemala insisted on adherence to these laws, the
would- be conquistador Juan Pérez de Cabrera abandoned his conquest
campaign rather than submit.
For the justifi cation of the use of force against the Indian realms, general
just-war doctrine had a crucial attraction: that it was well established and
widely accepted. It had two important drawbacks, though. First was the
obvious problem of determining whether the criteria for just wars were ac-
tually met in the cases at hand— that is, whether there really was a iusta
causa of the kind required. Second was the question of whether even a just
war could entail a right of outright conquest. Th e weakness of the Spanish
case on both of these counts was exposed by Vitoria in his two famous relec-
tions of 1539.
Vitoria devoted the bulk of his attention to the question of iusta causa. A
thorough analysis of this issue was his most distinctive contribution to the
debates over the Americas. He began by endorsing the standard canon- law
position (going back to Innocent IV) that, prior to the Spaniards’ arrival,
the Indians possessed lawful dominion over their lands. He then carefully
considered a list of seven possible justifi cations for war against the Indians,
fi nding all of them unpersuasive aft er close argument. Among these “unjust
titles” (as he called them) were the punishment of violations of natural law,
the claiming of title by right of discovery, and purported grants of sover-
eignty by an emperor or pope. Th ese were regarded as altogether invalid in
principle as justifi cations for war.
Without mentioning the requerimiento explicitly, Vitoria included
among his unjust titles a failure on the natives’ part to convert to Christi-
anity upon hearing “a simple announcement” of the faith. Only if the Indi-
ans refused to convert in the face of “miraculous signs or other reasons for
belief ” could compulsion be used— that is, if they positively repudiated the
Christian faith rather than merely passively declined to join it. Vitoria
added darkly that he had received no information of any such signs. “On