The tone of Gulliver's Travels is complex and undergoes several transformations over the course of the novel to reflect the narrator's changes in perspective. In Books 1, 2, and 3, Gulliver's tone is confident and sincere, reflecting his naive worldview. By the end of the novel, however, his experiences in the land of the Houyhnhnms have caused him to view his fellow humans with disgust and have rendered his tone bitter and cynical.
On numerous occasions, Gulliver speaks directly to the reader, and the tone of these passages is often self-conscious and somewhat defensive. In Book 1, Chapter 2, for example, he takes great pains to justify an act of defecation:
"But this was the only time I was ever guilty of so uncleanly an Action; for which I cannot but hope the candid Reader will give some Allowance, after he hath maturely and impartially considered my Case, and the Distress I was in."
The tone and style of this passage, which are reminiscent of other travel narratives, contrast sharply with the shocking and subversive content. This contrast between tone and content, along with Jonathan Swift's use of irony and understatement, establishes Gulliver's Travels as a work of satire. Though Gulliver's tone changes over the course of the novel, Swift's tone, in keeping with the genre, is consistently sarcastic and disdainful.