In the Middle Ages, the virtues were usually considered in terms of categories, branches, parts, manners and degrees. They were sorted and defined in an attempt to understand their meaning and their relationship to one another. This taxonomic approach to morality, found in many philosophical and exegetical texts, has been used as a framework through which to study Chaucerian virtue. However, as I hope to demonstrate in this thesis, Chaucer approaches virtue differently. Rather than present the virtues in abstraction as conceptual ideals, he contextualizes them through narrative. Throughout his work, he challenges the possibility of abstract definitions of virtue by showing that virtues must be considered in the human contexts that form, challenge and prove them. Building on work done on individual virtues and tales, this dissertation examines in detail how Chaucer handles virtue across a range of his work. Texts to be examined include the House of Fame, the Pardoner's Tale, the Knight's Tale and the Summoner's Tale (chapter one); the Physician's Tale, the Man of Law's Tale, and the Clerk's Tale (chapter two); the Wife of Bath's Tale, the Franklin's Tale, the Squire's Tale and the Tale of Sir Thopas (chapter three); Troilus and Criseyde (chapter four); and the Parson's Tale and the Retractions. Rather than imposing any potentially limiting taxonomic framework, it prioritizes the close study of his poetry. It also takes into account the changes Chaucer made to his sources, the traditions of virtue he had at his disposal, and the wide range of discussions he drew upon for his own examination of virtue. In its approach and its findings, this thesis fits within a critical tradition that shows that ethics cannot be abstracted from human experience and that the study of literature is a way of examining the richness of that experience.