Gulliver's final voyage brings him to a land ruled by horses — rational, wise, utterly honest creatures who have never learned to lie.

Among them, he finds a peace he never knew. The Houyhnhnms do not deceive, do not flatter, do not scheme. They live by reason and nature. Their society is ordered without being oppressive. Their kindness has no angle.

For six months, Gulliver lives among them. He begins to see himself — and all of humanity — with new eyes. The Houyhnhnms do not understand war, because they do not understand greed. They do not understand deception, because they cannot conceive of it.

But the Yahoos — savage human-like creatures — remind him, with painful clarity, of home. And Gulliver is a Yahoo. No amount of time with noble horses can change that.

He leaves with sorrow. He returns with disgust. And for the rest of his life, he cannot look at his own reflection without remembering what he truly is.

This is the cruelest and most honest thing Jonathan Swift ever wrote.