- Difference of religion is not a just cause for war.
- Extension of empire is not a just cause of war.
- Neither the personal glory of the prince nor any other advantage to him is a just cause for war.
- A wrong received is the only just cause for commencing a war.
- Not every kind and degree of wrong can suffice for commencing a war.
De Vitoria structures his treatise as responses to questions in the form of propositions and doubts in numerical order. The first question related to the jus ad bellum asks what is the reason and cause of a just war. His first proposition is that difference of religion is not sufficient to be a cause of a just war. He appeals to St. Thomas Aquinas on this point and adds, “… religion forms conscience and conscientious acts in ignorance of natural law are not guilty in justifying our penal interventions.” As a devout Catholic, he seemed to abhor the subjugation and slaughter of people in the name of religion as the Conquistadors were doing in Central and South America. The second proposition is that extension of empire is not sufficient for initiating a just war. He claims self-evidence on this point and sets up a reductio ad absurdum with an example of two belligerent states waging war against each other in the quest of empire. The contradiction is that since each state would be justified and therefore innocent, it would be unlawful to kill combatants on either side.
The third proposition is that neither the personal glory of the prince nor any other advantage to him is a just cause for war. He supports this claim with the premise that even though the prince is the only authority to initiate war, he should subordinate both peace and war to the people. The quest for glory and personal gain mark the difference between a lawful king and a tyrant in this respect. De Vitoria appeals to Aristotle to note that since the prince derives his authority from the state, he ought to use it for the good of the state. Lastly, he comments that the difference between freemen and slaves is that slaves are exploited for the good of the master while freemen exist in their own interest. De Vitoria makes this analogy to the jus ad bellum to show the difference between a prince initiating a just war on behalf and in support of the people to that of a tyrant conscripting subjects into an unjust war for glory and personal gain.
The last two propositions relate to the initiation of a just war based on wrongs done to the state by other states. The fourth proposition claims that the single and only cause for commencing a war is a wrong received. This would include war in self-defense and offensive war for avenging a wrong. De Vitoria appeals to Augustine and Aquinas for support in addition to the Bible relating to taking up the sword against an enemy. Specifically, he says, “ … a prince has no greater authority over foreigners than over his own subjects unless they have done something wrong.” From the Bible he quotes St. Paul from Romans, “He beareth not the sword in vain: for he is the minister of God, a revenger to execute wrath upon him that doeth evil.” The fifth and last proposition claims that not every kind and degree of wrong is sufficient for commencing a war and so he introduces the notion of proportionality into the Just War Theory. The premise for this claim is that fact that not every crime warrants death or atrocious punishment. De Vitoria also makes an appeal to the Bible by citing Deuteronomy that says, “… the degree of punishment ought to correspond to the measure of the offence.” These five propositions make up de Vitoria’s first canon of warfare. Besides the principles listed above, he argues that a prince should only reluctantly initiate war and live in peace as St. Paul urges in Romans. The prince should also remember that, “… others are his neighbors, whom we are bound to love as ourselves, and that we all have one common Lord, before whose tribunal we shall have to render our account.”
It is important to frame de Vitoria’s argument within history to understand the importance of his contribution to Just War Theory and its implications in a modern context. The Spanish conquest of the Aztecs led by Cortés took place between 1591 and 1521, 11 years before de Vitoria wrote his treatise in 1532. The battle of Tenochtitlan alone saw the deaths of 40,000 Aztecs in a single day in the name of conquest, glory, and religious justification. In 1517, Martin Luther posted his 95 theses on the door of the Castle Church in Wittenberg and began the Protestant Reformation that would lead to violence such as the Knights War of 1522 and the Peasants War of 1524 that left over 100,000 dead. Religious based violence and war was spreading throughout Europe and would continue to do so until the signing of the peace treaties of Westphalia in 1648. As such, de Vitoria was ahead of his time with his propositions that war based on religion, empire, and glory was not a just cause for war. This is even more striking considering he was a Roman Catholic at a time when corruption and politics within the Church was rampant and led not only to the Reformation but the imprisonment of Pope Clement VII and the end of the Italian Renaissance in 1527. His claims, however, are not without difficulties and as I will show, need to be reformulated to include just trade to fit in the modern world.
Although religion is not a just cause for war as de Vitoria claims in his first proposition, it is the source through which morality and therefore right and wrong are determined. As such, this leaves open his fourth and fifth proposition to religious interpretation as to what qualifies as a wrong received and a just cause for war. Religious worldview colors the determination of both proportionality and threshold of a wrong received therefore entailing that a wrong received in one culture with one type of religious worldview would justify the initiation of a war while the same wrong to another culture with a different religious worldview would not meet that same threshold. The controversy surrounding the 2005 Danish Jyllands-Posten Muhammad cartoons that resulted in a Fatwah issued by Mahmoud-al Zahar, the leader of Hamas, is an example of difference in belief of wrong received based on religious worldview. For most people in the U.S. and Europe, the issue was a matter of free speech and not considered the level of wrong that much of the Islamic world held it to be. To many Muslims, the cartoons were blasphemous to the point that many, including Mahmoud-al Zahar, believed that violence against Denmark and the cartoonist was justified. The argument for or against such an edict is beyond the scope of this essay; however, it is clear that religion, arguably in an indirect manner, continues to play a role for the justification of violence. A stronger formulation of de Vitoria’s jus ad bellum would have to include not only the proposition that religion is not a just cause of war but cultural and/or religious wrongs never meet the threshold to initiate a just war.
The modern world is certainly different from the world of de Vitoria with borders meaning less now than ever before. Trade is also different today than in his time with a global economy that has affected political dynamics, interdependency, and, in a sense, justice. Even though de Vitoria provides a prima facie argument against unjust war, his propositions must be reformulated to fit in this modern world. National self-sufficiency is desirable but mostly unattainable with global resource distribution scattered and uneven. Unjust trade practices, sanctions, and prime resource control create a potential for suffering that may justify a wrong that meets the threshold of a just cause for war. As such, a provision for just trade would have to be added to his jus ad bellum to insure against this. Skyrocketing food prices around the world has led to violence in Haiti and Africa while 15% of all gas in the United States comes from bio-fuels derived from food. 2 billion people are starving while 860 million cars are in use throughout the world, 62 million in the U.S. alone. It may be justifiable in the modern world to initiate a just war to demand this right to subsistence against the unfair advantage of trade. De Vitoria’s intent was the elimination of all war and the propagation of peace among all peoples of the earth. If he were alive today, trade would be a legitimate concern for him in the attainment of such peace. Further, his principle of justice, in a modern context, would have to more clearly define "wrong received" and account for war in the name of humanitarian intervention and preemptive war in the name of self-defense along with how his principles would be used under the current U.N. charter.