Jonathan Swift once wrote, "Satire, being leveled at all, is never resented for an offense by any." He had much to indict concerning almost every aspect of the society in which he lived. Gulliver's Travels was his way of convincing people to listen. The biting satire is written in the form of a travelogue, which was then a popular genre. Swift does not develop his narrator's character as one would do with the hero of a novel. Instead, he uses Gulliver as a mask, behind which he can attack the abuses of society and the weakness of human nature. Gulliver sometimes candidly voices Swift's own opinions, while at other times, when he speaks the opposite of what Swift believes, he becomes an "inverted mouthpiece." Gulliver is, therefore, a complex tool, as well as the voice of Swift himself.

During Gulliver's first voyage to Lilliput, his straightforward descriptions convey exactly what Swift desired to impart concerning Protestant England and Catholic France. Book I is a satire of the foolishness of cultures and the animosities they engender. The Big Endians and the Little Endians fight and die over the argument about which end of an egg is the appropriate one to break. The original statute mandates only "that all true believers shall break their eggs at the convenient end" (41). The upheavals Gulliver chronicles have easily recognizable parallels in the history of the conflict between Protestants and Catholics in England and France. Thus, Swift uses Gulliver to condemn this struggle as a useless, wasteful frivolity.

In Book II, Swift presents Gulliver as a fool whose uninformed ideas are demolished by the morally upright king of Brobdingnag. Swift advances his own ideas through the obvious foolishness of Gulliver's opposite opinion. Gulliver celebrates the merits of England and tries to convince the king that it is an exemplary and worthy country. Yet the king's "doubts, queries, and objections" (128) reveal the shortcomings of the English government and the weaknesses of its officials. The wise monarch brings to light the avarice and corruption of English lords, the lack of merit or qualification of priests or officials, the inefficiency of courts, and the mismanagement of the treasury. Gulliver's debauched nature also reveals itself in the discussion of gunpowder, which Gulliver highly values for the death and destruction it causes. Through Gulliver's ignorant nature, Swift satirizes unjust aggression. Gulliver has his own criticisms of the Brobdingnagians which Swift uses to prove their true merit. Gulliver dismisses government by common sense and reasoning as rule within "very narrow bounds" (136). Gulliver judges their learning as defective, since it focuses on useful arts without regarding "abstractions and transcendentals." Their laws are open to no more than one interpretation, so Gulliver credits the people with the fault of not being "mercurial enough." Swift uses Gulliver to contrast his own views on political and social mores with those of his opponents.

Swift pursues the same strategy, with Gulliver as his pawn, in Book III. Gulliver considers the wise political philosophers on Lagado to be "wholly out of their senses" (192). Gulliver scorns ideas such as selecting officials based on wisdom and virtue, rewarding merit, and instructing princes to mediate their own interests with those of the people. Gulliver approves of ideas which are truly ridiculous. He admires a certain doctor's proposals, which include physically abusing ministers to improve their memories and causing two opposite party members to exchange half their brain to mediate disputes. In these episodes, Gulliver does not speak what Swift wishes to impart to his readers. Yet, Gulliver advances the satire by criticizing ideal methods or advocating what is plainly wrong, thus imparting good sense to the reader.

Gulliver exposes the vanity of human beings during the various voyages he takes in Book III. On Laputa, the people are completely obsessed with complicated mathematics and disregard the practicality of simple geometry. Their knowledge does not enhance their wisdom. Their quality of life and peace of mind are both sacrificed, since they are perpetually in a state of worry over cosmic catastrophes. Gulliver's candid, neutral observations highlight their pitiable state, which Swift considered to be the same as that of the enlightened scientists of his age. Later, Gulliver's naÏve reaction to the Struldbrugs emphasizes the foolishness of humans' desire to live forever. When Gulliver describes what he would do with eternal life, he represents the reasons people so desire it. First and foremost, he desires to benefit himself by gaining riches and acquiring education in arts and sciences in order to become a great sage. Secondly, he would try to benefit society by passing on his knowledge. However, as Gulliver discovers, eternal life brings the exact opposite of what he and Swift's readers would assume. Instead of being rich, Struldbrugs are poor. Instead of being wise, they know nothing of the present age and cannot get along because they have no ability to communicate. They do not improve the present age, but instead, common vices are magnified in them. They are not respected, but despised by all other people. Swift here satirizes the idea of progress over time and the smugness he perceives in those who believe they are improving the human race. Swift uses Gulliver as an exhibition to prove that human nature is and will remain weak.

To further this idea, Swift makes clear in Book IV that Gulliver has not grown as a result of his travels. Gulliver tries to adopt the Houyhnhnm lifestyle and loses his dignity, just as the Balnibarbians who imitate the Laputans bring themselves poverty and hardship. Through Gulliver, Swift stresses the indispensability of balance. The Yahoos and the Houyhnhnms represent each side of human beings' dualistic nature. Gulliver makes the mistake of fully embracing the intellectual side while stifling love and passion. Thus, Swift makes the point that, like Count Munodi and Don Pedro, one must moderate between intellectual and passionate aspects of his or her nature. The last voyage suggests that the weakness of human nature stems in part from a failure to appropriately balance these two elements.

In the words of Juvenal, "It's hard not to write a satire." Swift perceived much folly in his own society and in human nature in general. He wrote his own epitaph, saying, "Here lies Jonathan Swift, where savage indignation can no longer lacerate his heart." The events and contemporary figures satirized in this work are unrecognizable to the average modern reader, but Swift's skill in exposing the weakness of human nature is still striking. This is why Gulliver's Travels endures as an ironic masterpiece.