 Perhaps the oldest distinctive philosophical problem of post-Columbian Latin American philosophy concerns the rights of indigenous populations in the Americas, and the duties of those governments that claimed jurisdiction over them. In the mid-sixteenth century, there were serious reservations on the part of a number of philosophers, theologians, and legal theorists concerning the validity of the Spanish wars of conquest. Francisco Vitoria’s developments of just war theory were among the earliest and most lasting philosophical contributions to the topic. One of the most significant issues for sixteenth century thinkers in Spain was whether the indigenous populations were natural slaves or not. Whether the Spanish Crown could “pacify” the indigenous populations through violence—or whether more peaceful means of persuasion and political control were necessary—was perceived to turn on whether the indigenous populations were natural slaves. Relatedly, the outcome of this dispute had implications for the duties of the Spanish Crown to the indigenous population, and correspondingly, the manner in which the indigenous populations ought to be treated (Canteñs 2010).