Until recent years, Chaucer's "Tale of Melibee" was scorned by most critics as a boring conglomeration of proverbs. As a result, little attempt has been made to understand the tale's content and the reason for its popularity in the Middle Ages. However, D. W. Robertson, in his reevaluation of the headlink between "Sir Thopas" and "Melibee" concludes that Chaucer intended ''Melibee" to contain all the sententious meaning which underlies the other tales. Presupposing that the tale may prove to be the keystone of The Canterbury Tales, this thesis purposes to explicate "Melibee" in its medieval context and to show its vital tie with the thematics of the other tales. The first chapter summarizes relevant Chaucer criticism on ''Melibee" and introduces the Robertsonian analysis of the headlink. Chapter two correlates the text with St. Augustine's commentary on the seven steps to wisdom found in De doctrina Christiana. In chapter three, the tales surrounding ''Melibee" in Fragment VII are explicated in light of their relationship to "Melibee" in the seven part schema. Special emphasis is given to the analysis of "The Shipman's Tale" since until this time there has been no "patristic" analysis of the story. The fourth chapter briefly draws the correlation between the seven steps to wisdom within ''Melibee" and the seven-part progression followed in the overall thematic structure of the Tales. Thus, the ''Melibee" is shown to be the key to discovering the rationale for Chaucer's ordering of the tales and also the key to understanding the intended theological "sentence" of each individual story. / M.A.