In the management of these various subjects, Ondegardo displays both acuteness and erudition. He never shrinks from the discussion, however difficult; and while he gives his conclusions with an air of modesty, it is evident that he feels conscious of having derived his information through the most authentic channels. He rejects the fabulous with disdain;decides on the probabilities of such facts as he relates, and candidly exposes the deficiency of evidence. Far from displaying the simple enthusiasm of the well-meaning but credulous missionary, he proceeds with the cool and cautious step of a lawyer accustomed to the conflict of testimony and the uncertainty of oral tradition. This circumspect manner of proceeding, and the temperate character of his judgments, entitle Ondegardo to much higher consideration as an authority than most of his countrymen who have treated of Indian antiquities.
There runs through his writings a vein of humanity, shown particularly in his tenderness to the unfortunate natives, to whose ancient civilization he does entire, but not extravagant, justice; while, like Sarmiento, he fearlessly denounces the excesses of his own countrymen, and admits the dark reproach they had brought on the honor of the nation. But while this censure forms the strongest ground for condemnation of the Conquerors, since it comes from the lips of a Spaniard like themselves, it proves, also, that Spain in this age of violence could send forth from her bosom wise and good men who refused to make common cause with the licentious rabble around them. Indeed, proof enough is given in these very memorials of the unceasing efforts of the colonial government, from the good viceroy Mendoza downwards, to secure protection and the benefit of a mild legislation to the unfortunate natives. But the iron Conquerors, and the colonist whose heart softened only to the touch of gold, presented a formidable barrier to improvement.