1. Gulliver’s Travels Part 4 Chapters IX - XII

2. Chapter IX
The Houyhnhnms hold one of their four-year grand assemblies while Gulliver is there. They go back to an old debate: whether Yahoos should be wiped off the face of the Earth.

3. Chapter IX
On the side of "yes": they're disgusting and they have to be watched constantly to keep them from doing bad things.
The Houyhnhnms caught and tamed their children.
The Master Horse tells his fellows that, in Gulliver's land, Houyhnhnms are the servants and Yahoos are the rational animals.

4. Continued
The Master Horse also informs them about the human practice of sterilizing horses to make them less aggressive – why don't the Houyhnhnms try this method on young Yahoos of their own country?
This way, the Houyhnhnms could make the Yahoos more docile, which would mean they wouldn't need to kill them all.

5. Continued
The Houyhnhnms don't write anything down; they rely on oral records for their history.
They also don't have much in the way of astronomy, except to measure months and years.
They write beautiful poetry about friendship and in praise of their athletes.
All of their words for something bad are connected to Yahoos, so a poorly built house is ynholmhmrohlnw Yahoo, and a stone that cuts their feet, ynlhmndwihlma Yahoo

6. Chapter X A room is made for Gulliver, and he furnishes it well.
He also makes new clothes for himself and settles into life with the Houyhnhnms quite easily. 
He begins to think of his friends and family back home as Yahoos. 
However, he is called by his master and told that others have taken offense at his being kept in the house as a Houyhnhnm.
The master has no choice but to ask Gulliver to leave. Gulliver is very upset to hear that he is to be banished.
He builds a canoe with the help of a fellow-servant and departs sadly.

7. Continued It is February 15, 1714.
Gulliver does not want to return to Europe, and so he begins to search for an island where he can live as he likes.
He finds land and discovers natives there. He is struck by an arrow and tries to escape the natives’ darts by paddling out to sea.
He sees a sail in the distance and thinks of going toward it, but then decides he would rather live with the barbarians than the European Yahoos, so he hides from the ship.
The seamen, including Don Pedro de Mendez, discover him after landing near his hiding place.

8. Continued
They question him, laughing at his strange horse-like manner of speaking, and cannot understand his desire to escape from their ship.
Don Pedro treats Gulliver hospitably, offering him food, drink, and clothes, but Gulliver can think of him only as a Yahoo and is thus repulsed by him.
Gulliver is forced to travel back to England, where he returns to his family, which has been convinced that he is dead.
He is filled with disgust and contempt for them. For a year he cannot stand to be near his wife and children, and he buys two horses and converses with them for four hours each day.

9. Chapter XII
Gulliver claims that everything he has written is absolutely true.
Gulliver's motto is: "Though Fortune has made Sinon wretched, she has not made him untrue and a liar." In other words, though Gulliver is not happy about having left Houyhnhnm Land, he still refuses to lie about any of his experiences.
Gulliver has been warned that he must first relate his experiences to an English secretary of state in order to give England the opportunity of invading the lands he has visited.
It wouldn't be profitable to try: the Lilliputians are too small to be worth it, the Brobdingnagians, too large and dangerous, and the Laputians, literally out of reach.

10. Continued
A further reason why Gulliver doesn't want the Europeans to conquer the lands he has seen is because they don't seem to want to be conquered.
Taking their lands against their will is cruel.
Gulliver is sitting in his garden thinking; he is instructing his family as best he can; he is applying the lessons of Houyhnhnm Land; he is looking at his face in the mirror to get used to the features of Yahoos; and he is mourning the treatment of Houyhnhnms in England.

11. Thanks
By Arfat