In Chapter 10, Swift has shown us Gulliver's fierce pride separating him from the Yahoos. He now shows this pride separating Gulliver from his own kind of (European) Yahoo. The savages who shoot arrows at Gulliver are, morally, somewhere between the depraved Yahoos and Pedro de Mendez. Mendez is a good and charitable man. He is not a rationalist stoic or a Deist filled with theories about the exalted dignity and natural benevolence of human nature. Yet Gulliver has lost his ability to evaluate; he treats Mendez as though the captain were merely a Yahoo. Mendez is a true Christian and shows the Christian virtue of charity. But blind to common sense, Gulliver cannot believe that a Yahoo can show virtue.
Swift has now concluded his illustration on humans' basic nature. Gulliver could not make himself a horse. He is not innocent or rational. He is, by nature, a Yahoo. But, as a European Yahoo, Gulliver should use his driblet of reason to improve himself; instead, he uses his reason to magnify his worst vice: his pride. Gulliver's pride has swelled out of all proportion; he has "reasoned" himself into rejecting his species and his nature: Gulliver is virtually a madman. His attitudes when he arrives in London make him a source of derision, for Gulliver seeks to change his basic nature by thinking; reason becomes the sole guide of his life.
