Chaucer's General Prologue is a robust celebration of human diversity, yet it also engages in social stereotypes. As an Estates Satire, its purpose is to show the various members of the medieval feudal estates and to mock members of society in terms of their deviation from the ideal of their estate. The feudal society claimed that society is strongest when every member stays in place and fulfills the duties of the place into which he or she is born. Chaucer the Pilgrim—the naive narrator of the Prologue—claims everyone is "worthy," yet it becomes clear quite soon that the reader must find ways in which worthiness is compromised by individual pilgrim's tendency to want to rise to a higher status or to abandon the standards of behavior assigned to a specific way of life.
Those who fight must protect the state from harm through battle, but they should do so only for noble causes and by fighting according to the chivalric ideal. Among the knight, the squire, and the yeoman, it seems that the knight most upholds these ideals yet also seems to have become something of a mercenary in the era's crusades. Terry Jones' book Chaucer's Knight details some of the nuances in the sketch the prologue offers, and "The Knight's Tale" is certainly marked by the knight's complicated relationship to love and war. The Squire is motivated more by romance than political idealism, using the tools of chivalry to achieve courtly attention, and the Yeoman is even further removed from the ideal.
Similarly, those who pray—the Prioress, the Monk, and the Friar—creating a descending scale in terms of those who pray on behalf of others. While the Prioress seems to care more for social than spiritual grace, the Monk himself seeks to ignore his order's rules, and the Friar is downright sinful in his practice. The simple parson is the pilgrim who most exemplifies the ideals of his place and is least ironically portrayed:
He was a shepherde and noght a mercenarie. And thogh he hooly were and vertuous, He was to synful men nat despitous, (Gen Prologue, lines 514–16)
Among those who work—the majority of the pilgrims—Chaucer offers a range of figures who skirt the demands of honest labor. The Miller, for instance, keeps his finger on the scale when measuring wheat. The Cook has a nasty open wound on his leg. The Clerk from Oxford studies by living off of others' money. The Shipman seems more pirate than noble wayfarer.
The game in the General Prologue is to read the details offered casually about each pilgrim and see in what ways they are drifting from their estate's ideal. Chaucer's own poetry is lively enough to suggest a complex characterization, but the poem does not fully realize round characterization such as one finds in Shakespeare. Irony, the juxtaposition of characters among each other, and the linking of pilgrim to tale told creates a more interesting mode of characterization than one expects in medieval literature.