he specific metaphors in each of the four voyages. Firstly, Swift went to great pains to present Gulliver's Travels in the genuine, standard form of the popular travelogues of the time. Gulliver, the reader is told, was a seaman, first in the capacity of a ship's surgeon, then as the captain of several ships. Swift creates a realistic framework by incorporating nautical jargon, descriptive detail that is related in a "factual, ship's-log" style, and repeated claims by Gulliver, in his narrative, "to relate plain matter(s) of fact in the simplest manner and style." This framework provides a sense of realism and versimilitude that contrasts sharply with the fantastic nature of the tales, and establishes the first ironic layer of The Travels. As Tuveson points out (58), "In Gulliver's Travels there is a constant shuttling back and forth between real and unreal, normal and absurd...until our standards of credulity are so relaxed that we are ready to buy a pig in a poke." The four books of the Travels are also presented in a parallel way so that voyages 1 and 2 focus on criticism of various aspects of English society at the time, and man within this society, while voyages 3 and 4 are more preoccupied with human nature itself, (Downie, 281). However, all of these elements overlap, and with each voyage, Gulliver, and thus the reader, is treated not only to differing but ever deepening views of human nature that climax in Gulliver's epiphany when he identifies himself with the detestable Yahoos. As such, the overall structure also works like a spiral leading to a center of self-realization. Or, as Tuveson puts it, Swift's satire shifts from "foreign to domestic scenes, from institutions to individuals, from mankind to man, from others to ourselves," (62).
             The choice of metaphor in each voyage serves more particularly the various points of Swift's satiric vision. "The effect of reducing the scale of life in Lilliput is to strip human affair...