What is lawful in war--General Rules derived from the law of nature--Stratagems and lies--Arrangement of the following parts--First rule, all things necessary to the end lawful--Right resulting not only from the origin of a war, but from causes growing out of the same--Certain consequences justifiable, though not originally lawful--What measures are lawful against those who furnish an enemy with supplies--Stratagems--Negative--Positive--Sometimes allowable to use words in a sense different from the general acceptation--A lie according to the true notion of it injurious to the rights of others--Falsehood allowable in order to deceive children or madmen--Any one addressing another without intentions to deceive, not answerable for the misconceptions of a third person--A person not answerable for the wilful mistakes of those to whom he speaks--The fictitious threats of a person in authority--Fiction allowable in order to save the lives of the innocent, or to promote other equally important purposes--Deception lawful against an enemy, but not including promises, or oaths--To forbear using this privilege an act of generosity and Christian simplicity--Not allowable to urge others to what is unlawful for them, but not for us to do--Allowable to use the services of deserters. I. Having, in the preceding books, considered by what persons, and for what causes, war may be justly declared and undertaken, the subject necessarily leads to an inquiry into the circumstances, under which war may be undertaken, into the extent, to which it may be carried, and into the manner, in which its rights may be enforced. Now all these matters may be viewed in the light of privileges resulting simply from the law of nature and of nations, or as the effects of some prior treaty or promise. But the actions, which are authorised by the law of nature, are those that are first entitled to attention.