“The world is indeed a sick thing; it is the kind of fur on which neither hide no hair is any good. The healthy heroes are rare, and God provides them at a dear price. Still the world must be ruled, if men are not to become wild beasts. So things in the world in general remain mere patchwork and beggary; it is a veritable hospital, in which princes, lords, and all rulers lack wisdom and courage–that is, success and direction from God–even as the sick person lacks strength and power. So here one must patch and darn and help oneself with the laws, sayings, and examples of the heroes as they are recorded in books. Thus we must continue to be disciples of those speechless masters which we call books.” Martin Luther, Commentary on Psalm 101 [:1], in Luther’s Works, vol. 13, p. 164. 
In this commentary Dr. Luther sought to advise the new ruler of Electoral Saxony on being a Christian prince. John Frederick followed his father, John the Steadfast, as Elector of Saxony. His support of the Reformation led to his military defeat to Emperor Charles V, subsequent imprisonment, and loss of much of his territory.
Written in 1534, Dr. Luther advised the new prince on how to rule properly. He drew upon biblical texts but also from ancient Greek and Roman writings. Luther advises rulers to turn to the heroes of the past and to their wisdom. After the statement recorded above, Luther continued:
“Yet we never do it as well as it is written there; we crawl after it and cling to it as to a bench or to a cane. In addition, we also follow the advice of the best people who live in our midst, until the time comes in which God again provides a healthy hero or a wondrous man, in whose hand all things improve or at least fare better than is written in any book.” Ibid.
