Ethics and Exemplary Narrative in Chaucer and Gower

A lively defence of the ethics of exemplary narrative, and a detailed account of its forms and functioning in the works of Geoffrey Chaucer and John Gower. Why do medieval writers routinely make use of exemplary rhetoric? How does it work, and what are its ethical and poetical values? And if Chaucer and Gower must be seen as vigorously subverting it, then why do they persist in using it?