The whole question was, moreover, argued out at that time between Las Casas and Sepulveda, historiographer to the Emperor Charles V. Sepulveda contended that more could be effected against barbarism by a month of war than by 100 years of preaching; and in his famous dispute with Las Casas at Valladolid in 1550, defended the justice of all wars undertaken against the natives of the New World, either on the ground of the latter’s sin and wickedness, or on the plea of protecting them from the cruelties of their own fellow-countrymen; the latter plea being one to which in recent English wars a prominent place has been always given. Las Casas replied--and his reply is unanswerable--that even human sacrifices are a smaller evil than indiscriminate warfare. He might have added that military contact between people unequally civilised does more to barbarise the civilised than to civilise the barbarous population. It is well worthy of notice and reflection that the European battle-fields became distinctly more barbarous after habits of greater ferocity had been acquired in wars beyond the Atlantic, in which the customary restraints were forgotten, and the ties of a common human nature dissolved by the differences of religion and race. The same effect resulted in Roman history, when the extended dominion of the Republic brought its armies into contact with foes beyond the sea. The Roman annalists bear witness to the deterioration that ensued both in their modes of waging war and in the national character.[218] It is in an Asiatic war that we first hear of a Roman general poisoning the springs;[219] in a war for the possession of Crete that the Cretan captives preferred to poison themselves rather than suffer the cruelties inflicted on them by Metellus;[220] in the Thracian war that the Romans cut off their prisoners’ hands, as Cæsar afterwards did those of the Gauls.[221] And we should remember that a practical English statesman like Cobden foresaw, as a possible evil result of the closer relations between England and the East, a similar deterioration in the national character of his countrymen. ‘With another war or two,’ he wrote, ‘in India and China, the English people would have an appetite for bull-fights if not for gladiators.’[222]