Gulliver's master attends one of the Houyhnhnm assemblies, and, when he returns, he relates to Gulliver what happened. One horse, he says, contended that the filthy and vicious Yahoos should be exterminated because they are not native to the Country of the Houyhnhnms, they are instinctively hated, and they have been allowed to increase because they can be used as beasts of burden. It would be better if the Houyhnhnms had bred the useful, sweet-smelling, and hard-working donkey. Gulliver's master advanced an argument at the assembly that he borrowed from Gulliver: If Yahoos in England castrate Houyhnhnms, why couldn't the Houyhnhnms castrate the Yahoos?
Then Gulliver tells us more about the Houyhnhnms: They are a reasonable and healthy race. They understand the nature of the eclipse (the sum of their astronomy). They use only months to reckon time. They have no literature but do compose poetry which is moral and accurate. Their only word for evil is Yahoo. As for their houses, they build crude but clean and useful buildings. They use their hollow hooves as we use fingers and, considering this, are most adept. When Houyhnhnms die, they are buried quietly; there are no rituals and there is no mourning.
In this chapter, Swift continues his thematic assault on humanity as represented by the Yahoos. The most obvious example relates to the general assembly's debate over the status of the Yahoos. The arguments for exterminating the Yahoos are compelling: The Yahoos are "the most filthy, noisome, and deformed animals which nature ever produced . . . " and they are "restive and indocible, mischievous and malicious." In terms of their evolution, the words used to describe the Yahoos are "degenerating by degrees." Not only this, but Gulliver tells the reader that the only reason that the Yahoos were eventually rounded up into herds was because the Houyhnhnms had "neglected to cultivate the breed of asses [donkeys and burros]" needed to do pulling and other basic labor tasks required in the Houyhnhnm society. In short, Yahoos are unnatural beasts and are hated by every other animal. Swift takes a slash at the philosophers of progress by suggesting that the Yahoos are simply a little further on the road to degeneration than are Europeans.
Gulliver cannot stand the Yahoos; he even suggests a method for exterminating them. Yet remember that, except for a semblance of reason and some clothing, he is very much like a Yahoo — indeed, he is a Yahoo. Why does he act this way? He has a fierce — and pathetic — pride, and this pride has given him disgust for his own species. He cannot bear to look at, and accept, the most squalid side of human nature. The alien, uncharitable, coldly rational horses seem far better creatures to try to emulate.
indocible (indocile) not easy to teach or discipline.
aborigines of the land aborigines are the first or earliest known inhabitants of a region; here, meaning that the Yahoos were not native to the land of the Houyhnhnms — they came from some other location.
frog of the foot a triangular, horny pad in the posterior half of the sole of a horse's hoof.