Gentilesse by Chaucer is an interesting poem discussing what it really means to be a noble man.  “vertu to love and vice for to flee” is the key point Chaucer is pushing meaning that virtue to love and refraining from vices are the most important elements for a man.  Whats even more interesting is that he also says that a person can obtain all the wealth in the world and be the most virtuous man but this is all dependent on whether or not his heirs are also virtuous.  This is an interesting way to depict how to determine nobility based on both the merit of the man and his linage.