In the portraits of the Parson and the Ploughman, Chaucer gives a positive expression to two medieval estates ideals – those of the clergy and the peasantry. The Clerk and the Knight are also presented as individuals who live up to an ideal of their estate, but Chaucer's attitude to the particular ideals that they embody is an elusive one. The ideal of chivalry underlying the Knight's portrait is treated in a later chapter where it can be usefully contrasted with that of the Squire; here I should like to discuss the Parson, the Ploughman and the Clerk.

Although most of the Canterbury pilgrims have failings or vices, Chaucer portrays idealised representatives of the three estates which form the skeletal structure of medieval society – Knight, Parson, Ploughman. From this observation it has been deduced that although Chaucer wished to criticise individuals for failing in their social and moral duties, he did not wish to attack the social ideology of medieval society, or the view that social cohesion depends on the interchange of specialised services provided by each class. Certainly it is striking that Chaucer not only presents the Parson and the Ploughman as ideal members of their respective classes, but also indicates how each benefits the other. Yet the isolated position of this sense of ‘common profit’ in the Prologue is also significant, and examination of the Clerk's portrait will modify the view that this is the social ethic implicit in the Prologue.