During this earliest period of Spanish domination in America, under successive viceroys and subordinate rulers, by far the most important matter which arose for consideration or action was the treatment of the aborigines. Most momentous to them it was, certainly, and of no small consequence to Spain. Unfortunately, much damage was done before the subject was fairly understood; and afterward, evils continued because bad men were always at hand ready to risk future punishment for present benefits. Spain was so far away, and justice moved so slowly, if it moved at all, that this risk was seldom of the greatest. The sovereigns of Spain now found themselves called upon to rule two races in the New World, the white and the red. And it was not always easy to determine what should be done, what should be the relative attitude of one toward the other. As to the superiority of the white race there was no question. And among white men, Spaniards were the natural masters; and among Spaniards, Castilians possessed the first rights in the new lands the Genoese had found for them. All was plain enough so far. It was natural and right that Spaniards should be masters in America. Their claim was twofold; as discoverers, and as propagandists. But in just what category to place the red man was a question almost as puzzling as to tell who he was, and whence he came. Several times the question arose as to whether he had a soul, or a semi-soul, and whether the liquid so freely let by the conquerors was brute blood, or of as high proof as that which ran in Castilian veins. The savages were to be governed, of course; but how, as subjects or as slaves? Columbus was strongly in favor of Indian slavery. He had participated in the Portuguese slave-trade, and had found it profitable. Spaniards enslaved infidels, and why not heathens? Mahometans enslaved Christians, and Christians Mahometans. Likewise Christians enslaved Christians, white as well as black, though it began to be questioned in Spain whether it was quite proper to enslave white Christians. [Sidenote: SLAVERY.]