Houyhnhnms and Yahoos
Animal Rationale or Rationis Capax
What do the Yahoos and the Houynhnmns stand for? What moral was Swift drawing from them? The answer to the second question depends on the solution of the first. One solution could be that the Yahoos represent man has he actually is, self-seeking, sensual and depraved, while the Houyhnhnms symbolize what man ought to be, unselfish, rational, cultured. In the fourth voyage, Swift presents a case study for opposing states of nature, with the Yahoos representing the argument that man is governed by his passions, seeking his own advantage, pursuing pleasures and avoiding pain, and the Houyhnhnms representing the argument that man is governed by reason. If this is the case, then Swifts misanthropy was such that he saw men as the foul and disgusting Yahoos, and made it plain that reform of the species was out of the question. A major fault with this theory is that it leaves no place for Gulliver.
When attention is drawn to the figure of Gulliver himself, as distinct from his creator, Swift, he is taken to be the moral of the story. If you can't be a Houyhnhnm you don't need to be a Yahoo; just try to be like Gulliver. The trouble with this idea is that when taking a closer look at Gulliver, he isn't worth emulating. The final picture of him talking with the horses in the stable for four hours a day, unable to stand the company of his own family, makes him look foolish
Another theory is that Gulliver made a mistake in regarding the Houyhnhnms as models to be emulated: so far from being admirable creatures they are as repulsive as the Yahoos. The Yahoos might be ruled by their passions, but these have no human passions at all. On this view, Swift was not advocating, but attacking reason.
The voyage does seem to have a slight religious moral also. One of the oldest debates in Christianity concerns the nature of man since the fall of Adam. He was so corrupted by that event that left to his own devices he was beyond redemption. His passions naturally inclined him toward vice, and his reason, so far from bringing him out of his vicious ways, led him even further into error. Only Divine Relevation could bring men back to the straight and narrow path of virtue. Although man is naturally inclined toward evil, nevertheless his own unaided reason could bring him to a knowledge of moral truth.
The connection of the fourth voyage to this debate is obvious. The Yahoos symbolize man as the incorrigible sinner. The Houyhnhnms symbolize man, directed by reason, into the path of righteousness. The Houyhnhnm word for to die is Lhnuwnh. The word is strongly expressive in their language. It signifies, to retire to his first Mother. This is not a euphemism, for the Houyhnhnms cannot say the thing that is not. They have therefore some notion of existence after death, though of course they have not benefited from Christianity.
Reason was not enough for the Houyhnhnms. It did not enable them to imagine a different country from their own, so that they accused Gulliver of lying when he told them that he came from over the sea. They also failed to figure out what his clothes were. The Sorrel Nag who first discovered Gulliver undressed could only explain the sight by saying he was not the same thing when he slept as he appeared to be at other times. Gulliver could only show his master what his clothes were by undressing before him. The truth had to be revealed even to a Houyhnhnm.
The moral of the encounter with the Yahoos and the Houyhnhnms is that Reason alone might be enough for men if they would only use it properly. Yet instead of employing it as the Houyhnhnms did to eliminate passion, in the words of Gullivers host We made no other use of it than by its assistance to aggravate our natural corruptions, and to acquire new ones which Nature had not given us. Reason, instead of leading men into Virtue, led them into Vice. To the Houyhnhnms, therefore, they were not better than the Yahoos, they were