There are many justifications for war. Today, world leaders often cite the fight against terror, and the preservation of democracy, as the grounds for invading sovereign nations.  War waged under the banner of “goodness” is an age old concept.  Pope Innocent IV and Francisco de Vitoria both presented arguments describing the necessary conditions under which Christian powers could justly engage in wars against indigenous peoples for the sake of claiming their land.  their arguments ultimately reached different conclusions, the conflation of religious and natural wars was the greatest similarity between the two thinkers, and served to weaken both their arguments

Pope Innocent IV

Innocent contended that rational beings that chose not to believe in God should be punished, and indigenous peoples are rational beings that choose not to believe in God; therefore, indigenous peoples should be punished. War is therefore the appropriate form of punishment (Innocent 153). Disbelief in God constitutes a sin because it goes against the laws of nature that indigenous people themselves prescribe to, and if indigenous peoples act against the law of nature, they may be punished by the pope because the pope “has dominion not only over Christians but also over all infidels, since Christ had dominion over all” (Innocent 153). A clear issue with Innocent’s argument is the lack of reasonable connection between “punishment of indigenous peoples” and military conquest. While an objection to this issue can be the argument that war is a means of re-taking land already owned by the people, this line of thought conflates religious and natural law.

Francisco Vitoria

Vitoria however, proposes an alternate explanation, arguing that the “cause of the just war is to redress and avenge an offence” and that is is “lawful to meet force with force” (Vitoria 302). Lack of Christian faith does not constitute an offence, and therefore, is not a just cause for war. His argument follows the assumption that indigenous peoples can only be held under natural law , and thus cannot be governed by religious or human law but only by divine ones (Vitoria 292). “Divine law” falls under the heading of “natural law,” and is comprised of an unwritten code of conduct of moral norms that reflect the customs of diverse peoples, and thus, indigenous people cannot be judged by human statutes but only by divine ones. (Vitoria 292, Reichberg, Syse, and Begby 290).

Indigenous peoples possess true dominion “over the right of ownership” on the basis of natural law, considering they occupied American land before the Spaniards. The only relevant criteria derived “from natural law” is the capacity of reason for self-rule, and considering the indigenous peoples were indeed “self-governing”, Vitoria believed they possessed true dominion status (Reichberg, Syse and Begby 290).

A particular note of contention between Innocent and Vitoria was the pope’s authority and how far it could legitimately extend. Both Innocent and Vittoria claim the pope as the vicar of Christ, but Vitoria’s claim was to prove his non-authority over those who are not Christians since the pope cannot punish those are not Christian, while Innocent’s “Hold Land” argument conflated natural and religious laws, thus weakening his “Holy Land” argument. He argues that disbelief in God is a sin against natural law, but the argument is inherently religious since he claims that all those “who sinned against the law of nature were punished by God” (Innocent 153). Vitoria also subtly conflates religious and natural law in a way that he believed that natural law came from God. Like Innocent, he used passages from the bible as interpretations of natural law and considering the Bible is a religious, Vitoria’s conception of natural law cannot claim to have a clean separation from religious justifications or laws. In addition, Vitoria believes that Christians should “correct and direct” indigenous people towards Christianity, inherently prioritizing religious law over natural law.

Both Innocent and Vitoria addressed the question of what could be considered a just war: they put forward different arguments but both their arguments were weakened because of their conflation of religious and natural wars.


De Vitoria, Francisco. Francisco De Vitoria (ca. 1492-1546): Just War in the Age of Discovery. The Ethics of War: Classic and Contemporary Readings. Ed. Gregory M.Reichberg, Henrik Syse, and Endre Begby. Malden, MA: Blackwell Pub., 2006. 288-308.Print.

Innocent, IV. “On Vows and the Fulfilling of Vows,” Decretal Quod Super His (Decretals, III,34, 8), Nn. 1-4, 7-10 (f. 164vb). The Ethics of War: Classic and Contemporary Readings.Ed. Gregory M. Reichberg, Henrik Syse, and Endre Begby. Malden, MA: Blackwell.Pub., 2006. 152-55. Print.