Aquinas’ three conditions that make war “just” are: Proper authority, Just cause, and the right intention (PP. 4). The first condition states that war can only be declared by the highest authority in government, the head of state. The purpose of declaring war is to give the other state a chance to make peace. If the parties involved are not able to reach a peaceful settlement, then the head of state of of the second nation must refuse to resolve. At this point, both sides have tried to come to peace and haven’t and are aware that war is coming.
The second of Aquinas’ three conditions is the “Just Cause” principle. It states that in order for war to be declared, one must have a good reason. According to Aquinas ( and Augustine), good reasons …show more content…
(pg. 52). The conditions that must occur in order for this to be true and applied are: The bad effect was an unintended side effect, it is proportional to the good effect, there is no alternative to achieving the good effect, and lastly, the act is morally good or indifferent to begin with (PP. 4). What this means is that if one carries out a good action but there is a partial bad reaction that occurs because of it, it’s okay because it was unintended, unavoidable, and/or the only resort to obtain that necessary good action. One implication where this applies is self defense. If one is being attacked and that person kills their attacker, it would be justifiable due to the fact that it was an unintended outcome or the only option. That being said, Aquinas believed that if the death of the attacker was not an accident nor the only option, it is not justifiable because it is “outside the intention” (pg.52). Another implication where this could be applied is acts of war. Although Aquinas, himself, doesn’t implement it in this way, it is still highly applicable by reason of defense. Though it can be used in this situation as well, it is important to remember that staying alive alone is not a sufficient enough reason and one must be aware of the foreseen harm that will take