All of the lessons the Don learns about being chivalrous come from books, specifically the fabulous tales of King Arthur and his Knights of the Round Table. The influence of these tales was widespread. The code of chivalry espoused nine basic tenets: prowess, justice, loyalty, defense, humilty, courage, faith, largesse, and nobility.
Although Don Quixote carries his beliefs about righteous living to the extreme, I would argue that books on how to live are just as influential today as they ever have been. A look at the titles and topics of today New York TImes Bestselling Advice Books bears this out (5/30/07):
1. THE SECRET, by Rhonda Byrne
2. THE DANGEROUS BOOK FOR BOYS, by Conn Iggulden and Hal Iggulden
3. REPOSITION YOURSELF, by T. D. Jakes
4. THE EXCEPTIONAL PRESENTER, by Timothy J. Koegel
5. YOU: ON A DIET, by Michael F. Roizen and Mehmet C. Oz et al