Part IV: A Voyage to the Country of the Houyhnhnms
1.He gets to be captain of his ship, the Adventurer. He is abandoned by pirates in a landing boat and comes upon a race of hideous, deformed and savage humanoid creatures to which he conceives a violent antipathy. Shortly afterwards he meets the Houyhnhnms, a race of talking horses. They are the rulers, while the deformed creatures called Yahoos are human beings in their base form.
3. Gulliver discovers that, in their language, "Houyhnhnm" means both horse and "perfection of nature". (((Oat+ milk))))
Gulliver explains to the Master Horse about his own origins. There are no words in Houyhnhnm language for things like deception, power, wealth, lust, or envy.
5.The Master Horse wants to know why humans go to war. Gulliver answers: (1) ambition to conquer, (2) corruption of the government, (3) differences of opinion. Wars over opinions are the worst kind.
6. He tells the Master Horse that the nobility in his country are educated to be lazy and ignorant, and that there is frequent mixing of classes that damages noble bloodlines.
7. The Master Horse gives Gulliver his conclusions: the European Yahoos have only enough reason to make their natural corruption worse. Gulliver´s Land Yahoos and the Houyhnhnm Yahoos natures are the same: they hate each other more than other animals do, and will fight even without a reason.
8. Houyhnhnms believe that you should respect other people's ideas without trying to dominate with your own. When a female Houyhnhnm has had a foal of each gender, a couple will stop producing children. This is to keep Houyhnhnm Land from becoming overpopulated. If one Houyhnhnm couple has two sons and another has two daughters, they'll trade one to make sure that they have the set quantity of one boy and one girl. If one family has lost one or both children, another Houyhnhnm couple has to have a child to supply their loss.
10. One day the Master Horse comes to see Gulliver and to tell him that the Houyhnhnms have voted that Gulliver must go away. They worry that such a smart Yahoo might encourage the other Yahoos to rise up and kill the Houyhnhnm's cattle.
The Master Horse gives Gulliver two months to finish his boat, which he builds with the help of the sorrel nag. Finally he leaves Master Horse and whole his family.
11. The sailors bring Gulliver aboard their ship, which is heading for Lisbon in Portugal.
They arrive at Lisbon, and Don Pedro insists that Gulliver stay at his own house and borrow some clothes. After 10 days in Portugal, Don Pedro tells Gulliver that it is his responsibility to go back home to his family.