Division of war into public and private

The first and most essential division of war is that into public war, private war, and mixed war. A public war is that which is waged by him who has lawful authority to wage it; a private war, that which is waged by one who has not the lawful authority; and a mixed war is that which is on one side public, on the other side private. Let us deal first with private war, as the more ancient.

That private wars in some cases may be waged lawfully, so far as the law of nature is concerned, is, I think, sufficiently clear from what was said above, when we showed that the use of force to ward off injury is not in conflict with the law of nature. But possibly some may think that, after public tribunals had been established, private wars were not permissible. For although public tribunals are the creation not of nature but of man, it is, nevertheless, much more consistent with moral standards, and more conducive to the peace of individuals, that a matter be judicially investigated by one who has no personal interest in it, than that individuals, too often having only their own interests in view, should seek by their own hands to obtain that which they consider right; wherefore equity and reason given to us by nature declare that so praiseworthy an institution should have the fullest support. Says Paul the Jurist, ‘Individuals must not be permitted to do that which the magistrate can do in the name of the state, in order that there may be no occasion for raising a greater disturbance’.