The idea of the importance of a just cause of war may be traced, of course, in history, after the extinction of the grand pagan philosophy in which it had its origin. It was insisted on even by Christian writers who, like St. Augustine, did not regard all military service as wicked. What, he asked, were kingdoms but robberies on a vast scale, if their justice were put out of the reckoning.[334] A French writer of the time of Charles V. concluded that while soldiers who fell in a just cause were saved, those who died for an unjust cause perished in a state of mortal sin.[335] Even the Chevalier Bayard, who accompanied Charles VIII. without any scruple in his conquest of Naples, was fond of saying that all empires, kingdoms, and provinces were, if without the principle of justice, no better than forests full of brigands;[336] and the fine saying is attributed to him, that the strength of arms should only be employed for the establishment of right and equity. But on the whole the justice of the cause of war became of less and less importance as time went on; nor have our modern Christian societies ever derived benefit in that respect from the instruction or guidance of their churches at all equal to that which the society of pagan Rome derived from the institution of its Fecials, as the guardians of the national conscience. It was among the humane endeavours of Grotius to try to remedy this defect in modern States by establishing certain general principles by which it might be possible to test the pretext of any given war from the side of its justice. At first sight it appears obvious that a definite injury is the only justification for a resort to hostilities, or, in other words, that only a defensive war is just; but then the question arises how far defence may be anticipatory, and an injury feared or probable give the same rights as one actually sustained. The majority of wars, that have not been merely wars of conquest and robbery, may be traced to that principle in history, so well expressed by Livy, that men’s anxiety not to be afraid of others causes them to become objects of dread themselves.[337] For this reason Grotius refused to admit as a good _casus belli_ the fact that another nation was making warlike preparations, building garrisons and fortresses, or that its power might, if unchecked, grow to be dangerous. He also rejected the pretext of mere utility as a good ground for war, or such pleas as the need of better territory, the right of first discovery, or the improvement or punishment of barbarous nations.