Gulliver visits the Yahoos but cannot reconcile himself to their vulgarity. They eat frogs and fish and kennel in holes. They stink, cannot be housebroken, and hurl excrement at one another. When Gulliver goes swimming, he is cornered by one of the amorous females who embraces his naked body and, Gulliver says, would have sexually assaulted him had his protector, the Sorrel Nag, not saved him. In contrast to the Yahoos, the Houyhnhnms govern themselves wholly by reason. They take good care of their young, but they do it on the grounds of reason. Accordingly, they breed for strength and comeliness; no Houyhnhnm marries for either love or money. Also, there is no adultery. Once every four years, Gulliver tells us, the Houyhnhnms meet for an assembly to settle all problems. Not surprisingly, there are few or no problems that need solving.
Houyhnhnms are a breed of moral animal, different from the Yahoos or Europeans. We have, in fact, already seen this difference in Chapters 3 through 6. Houyhnhnm society is a rational (and, metaphorically, a bloodless) utopia. It contains details taken from Plato, as well as from More; both men proposed such societies as methods of curing people's vices. Swift demonstrates, however, that these utopias are only suitable to fully rational and totally innocent creatures; they are only inhabitable by the type of creature who doesn't need the cure.
The rest of Book IV is spent exploring Gulliver's pride — the extraordinary and perverted pride that makes him aspire to be a horse.
the sentiments of Socrates as Plato delivers them Socrates (470-399 B.C.) was an Athenian philosopher and teacher of Plato (427-347 B.C.), the Greek philosopher whose writings often feature Socrates in philosophical dialogues.