Hence Hobbes never thought of questioning the necessity of war. It was in his eyes the natural condition of European society; but certain rules were necessary both for its conduct and, where this was compatible with a nation’s dignity and prosperity, for its prevention. He held that international law was only a part of the Law of Nature, and that this Law of Nature laid certain obligations upon nations and their kings. Mediation must be employed between disputants as much as possible, the person of the mediators of peace being held inviolate; an umpire ought to be chosen to decide a controversy, to whose judgment the parties in dispute agree to submit themselves; such an arbiter must be impartial. These are all what Hobbes calls precepts of the Law of Nature. And he appeals to the Scriptures in confirmation of his assertion that peace is the way of righteousness and that the laws of nature of which these are a few are also laws of the heavenly kingdom. But peace is like the straight path of Christian endeavour, difficult to find and difficult to keep. We must seek after it where it may be found; but, having done this and sought in vain, we have no alternative but to fall back upon war. Reason requires “that every man ought to endeavour peace,” (_Lev._ I. Ch. XIV.) “as far as he has hope of obtaining it; and when he cannot obtain it, that he may seek, and use, all helps, and advantages of war.”[51] This, says Hobbes elsewhere, (_On Liberty_, Ch. I. 15) is the dictate of right reason, the first and fundamental law of nature. [51] We find the same rule laid down as early as the time of Dante. Cf. _De Monarchia_, Bk. II. 9:—“When two nations quarrel they are bound to try in every possible way to arrange the quarrel by means of discussion: it is only when this is hopeless that they may declare war.” _Kant’s Idea of a Perpetual Peace._