X. Nearly related to the last named method is that of single combat, a practice recommended under the idea that by the risque of two lives a quarrel might be decided, which would otherwise have cost the blood of thousands. In Livy we find Metius addressing Tullus in the following terms, "let us try some method of determining to whom the pre-eminence shall belong, without wasting the blood of each people." Strabo says it was the practice of the ancient Greeks, and Aeneas proposed it to Turnus, as the most equitable way of settling their pretensions. It is described too as the custom of the ancient Franks. XI. Although in doubtful cases, both sides are bound to devise every means of avoiding hostilities, yet it is a duty more incumbent upon the claimant than upon the immediate possessor of whatever may be the subject of dispute. For it is a rule not only of civil, but of natural law, that, where the pretensions are equal, those of the possessor are to be preferred. To the foregoing remarks an additional observation may be made, that if any one, knowing his pretensions to be just, cannot produce sufficient proofs to convict the intruder of injustice, he cannot lawfully have recourse to arms, because he has no OSTENSIBLE RIGHT, by which he can compel the intruder to relinquish the possession. XII. But where the right is ambiguous, and neither party has possession, the pretender, who refuses to divide the claims, may reasonably be charged with injustice. XIII. From what has been said it will not be difficult to settle a much agitated question, whether, with respect to those, who are the principal movers of a war, there can be justice on both sides. For there are distinctions proper to be made in the various acceptations of the word JUST. A thing is said to be just, either as to its causes, or its effects. The causes too may be confined either to justice in a PARTICULAR acceptation, or they may be extended so as to include under that name every kind of rectitude. Again, a particular acceptation may be divided into two kinds, one relating to the ACTION, and the other to the agent.[56] An agent may be said to act justly, when, in what he does, he commits no breach of STRICT LAW, though his conduct may not be conformable to equity.