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.
