By the quote above, Ludwig Wittgenstein suggests that Houyhnhnms could not have a true sense of good if they did not know what evil was. The Houyhnhnms also embody a sense of arrogance and bias that exists in humans. Their only sense of "evil" is in terms of the Yahoos. That is reflective of some governing institutions that blame others as the source of corruption and evil. Historically, groups like gypsies, Armenians, and Jews have fallen under that category of scapegoats. When the Houyhnhnms observe Gulliver, they immediately classify him as a Yahoo. By doing so, they do not act as rational creatures because they ignore the great number of differences and only observe superficial similarities. The idea of not being able to understand good without understanding evil can be explained in religious terms as well.Throughout Book IV, there are many links to Christian ideas. Ehrenpreis thinks that Swift's writing plays off a debate between Locke and Stillingfleet over the definition of "man". Stillingfleet uses a Trinitarian argument that defines man as "a creature that enjoys a special 'subsistence'." This definition is not practical because the "special subsistence" is not defined. Locke defines it as "that faculty, whereby man is supposed to be distinguished from beasts, and wherein it is evident he much surpasses them." It seems that Swift does not support either argument, because the physical "subsistence" of man is embodied in irrational creatures, while the intellectual "subsistence" is embodied in a rational beast. Knowles shows that by giving a beast reason, Swift can point out the fallibility of Deist thought. Anthony Collins wrote, "whosoever live by reason are Christians." Since the Houyhnhnms live by reason, then it can be implied that they are Christians. The ending of Book IV is another attack on Deist thought. The Deists thought "that every Man is bound to follow the Rules and Directions of that Measure of R...
