You might like to think about this last quote that comes as Gulliver concludes his narrative and how he struggles to reintegrate into his home life after being with the Yahoos and the Houyhnhnms:
My Reconcilement to the Yahoo-kind in general might not be so difficult, if they would be content with those Vices and Follies only which Nature hath entitled them to. I am not in the least provoked at the Sight of a Lawyer, a Pick-pocket, a Colonel... This is all according to the due Course of Things: But, when I behold a Lump of Deformity, and Diseases both in Body and Mind, smitten with Pride, it immediately breaks all the Measures of my Patience; neither shall I ever be able to comprehend how such an Animal and such a Vice could tally together.
There is of course massive satire in the way that he comes to associate European culture with that of the savage and oppressed Yahoos. By his belief that the sins of humans can be explained by the "due Course of Things," Gulliver shows how he believes, as the Houyhnhnms do themselves, that humanity is ungovernable and corrupt at its very core, just like the Yahoos. Humans are therefore satirised as being no more than animals or savage creatures who unfortunately have been given enough reason to make their corruption a problem. What is even worse is humanity's own inability to see themselves for the depraved creatures that they are and to consider themselves as actually being noble.