ABSTRACT
God inflicts wars as a just judge who will avenge the wickedness of humans against him, namely by allowing another wickedness at its full force. War does not belong to the category of good things, but of bad things, that only become licit and good to an extent, depending on a threefold cause. The cause must be first of all just, grave, and finally necessary. There are two kinds of fighting: one through debate, the other through violence. The justice of a war is derived from a truly grave cause; its necessity from the enemies. The discipline in the military camp is of great and necessary importance. It must always accompany the justice of the cause, so that the desired outcome is returned. Francisco de Victoria, the teacher of Melchior Cano makes the first proposition in the Theological Lectures, lecture six, on the right of war: A cause for just war is not diversity of religion.
