Gulliver meets the inhabitants of the Flying (Floating) Island, learns that it is called Laputa, and immediately realizes that the inhabitants are a distracted people who have a very limited attention span and very narrow interests; their main concerns are essentially mathematics and music. Gulliver observes the Laputans. Their clothes, which do not fit, are decorated with astrological symbols and musical figures. They spend their time listening to the music of the spheres. They believe in astrology and worry constantly that the sun will go out. The Laputan houses, he notices, are badly built, without accurate right angles. The Laputan women are highly sexed and adulterous, preferring men from the island of Balnibarbi. The Laputan husbands, who are so abstracted in mathematical and musical calculations, don't know that their wives are adulterous.
Here, Swift concentrates his satire on people's pride in reason. Reason, in Swift's era, was valued above all other faculties. Science was fast becoming a religion, with the telescope and the microscope as fountain-heads of Truth. Swift found this unnatural. He felt that too thorough an emphasis on reason obscured the human elements in a person's make-up. Even Swift's choice for the name of the flying island indicates his opinion of the Age of Reason. Gulliver explains to us what he believes Laputa to mean, but his speculations are wrong. The name Laputa comes from Spanish and means "the whore." We are reminded of Martin Luther's famous description of reason: "That Great Whore, Reason!" Luther became infuriated with reason because some of his opponents were using it to deny the Lutheran emphasis on faith. Swift was generally sympathetic to the Lutheran adherence to faith and the system of morality built upon it. By naming the island Laputa, he warns his readers that he is deprecating those rationalists and abstract reasoners who are antagonists of faith.
The Laputans are speculative and rationalistic philosophers. And they are dismal failures — as philosophers, as reasoners, and as men. They are devoted to the most ethereal of abstract disciplines — music and mathematics — but cannot play music well or figure accurately enough to build houses or tailor clothes. They are completely incompetent in practical affairs and don't even notice that their wives are notoriously unfaithful.
Swift uses the whoring wives of the Laputans to suggest that immorality accompanies abstract, proud reason. The story from Juvenal relates these licentious women directly with national morality and English politics. In addition, Swift also takes a poke at Walpole, the leader of the Whigs. The woman who runs away to live with a slave has reference to the stories that circulated about Walpole's wife.
Incorporating other political allusions, Swift chides George I by means of the Laputan's king's hospitality to Gulliver. George I was notorious for filling his administration with illiterate Germans from Hanover. The tailor's mistake in calculation applies to Isaac Newton, a mathematical theorist who dabbled in politics. Newton suffered ridicule because a printer made a mistake in one of the figures Newton used in computing the distance of the earth from the sun. Swift, however, had yet another quarrel with Newton. Newton recommended a scheme to debase Irish coinage that Swift believed was immoral and callous. Newton was a convenient model for Swift, who believed that he incorporated the essence of the immoral, abstract reasoning scientist. Swift also makes satirical use of the Laputan anxiety about the health of the sun and the comet theories. Many of his contemporaries were so interested in astrology, Swift believed, that they might worry over a comet and not notice their wives' infidelity.
quadrant an instrument similar to the sextant, used by naivgators for measuring the angular distance of the sun, a star, etc. from the horizon.
gallants men attentive and polite to women.
caprices sudden, impulsive changes in the way one thinks or acts.