The pagan religion, which prohibited only some of the grosser crimes, and which stopped the hand but meddled not with the heart, might have crimes that were inexplicable.
There are only two cases in which war is just: first, in order to resist the aggression of an enemy, and second, in order to help an ally who has been attacked.
The law of nations is naturally founded on this principle, that different nations ought in time of peace to do one another all the good they can, and in time of war as little injury as possible, without prejudicing their real interests.
Experience constantly proves that every man who has power is impelled to abuse it; he goes on till he is pulled up by some limits. Who would say it! virtue even has need of limits.
