This last principle, which is called propriety, from its fitness, according to the various things on which it turns, sometimes is limited to a very narrow point, the least departure from which is a deviation into vice; sometimes it allows a wider scope, so that some actions, even laudable in themselves, may be omitted or varied without crime. In this case there is not an immediate distinction between right and wrong; the shades are gradual, and their termination unperceived; not like a direct contrast, where the opposition is immediately seen, and the first step is a transgression of the fixed bounds. The general object of divine and human laws is to give the authority of obligation to what was only laudable in itself. It has been said above that an investigation of the laws of nature implies an inquiry, whether any particular action may be done without injustice: now by an act of injustice is understood that, which necessarily has in it any thing repugnant to the nature of a reasonable and social being. So far from any thing in the principles of nature being repugnant to war, every part of them indeed rather favours it. For the preservation of our lives and persons, which is the end of war, and the possession or acquirement of things necessary and useful to life is most suitable to those principles of nature, and to use force, if necessary, for those occasions, is no way dissonant to the principles of nature, since all animals are endowed with natural strength, sufficient to assist and defend themselves.