While John Locke’s impact on Jonathan Swift’s Gulliver’s Travels, an eighteenth-century satire, is a well-worn topic of scholarly discussion, Gulliver as the butt of a satire concerning an important aspect of Lockean epistemology has not been considered. In the 1690 Essay Concerning Human Understanding, Locke distinguishes between person (an abstract thinker) and man (an individual with a human shape but little capacity for thought). Locke’s differentiation underwrites the modern concept of intellectual and developmental disabilities. Cognitive ableism is the belief in the superiority of person over man, of the thinker over the individual with less capacity for thought. Approaching Book Four of the Travels from a disability studies perspective, this chapter argues that Locke’s person/man binary broadly comes into play, that the character of Gulliver straddles the person/man divide, and that his characterization parodies Locke’s distinction. Book Four satirizes cognitive ableism through its protagonist, who exhibits an extreme form of it.