A ship's surgeon recounts four voyages to fantastical realms: a kingdom of tiny people where political pettiness is magnified; a land of giants that reverses perspectives on power and vulnerability; an island of eccentric thinkers and impractical theorists that satirizes abstract learning; and a society of rational horses contrasted with brutish human-like creatures, provoking profound misgivings about human nature. Through sustained irony and invention, the travel narratives critique government, science, pride, and the moral failings of mankind, ending in the narrator's alienation.