Advice on Conduct Toward Friends and Enemies

23 There is a supreme rule of conduct required in these good men-at-arms…they should be humble among their friends, proud and bold against their foes, tender and merciful toward those who need assistance, cruel avengers against their enemies, pleasant and amiable with all others, for the men of worth tell you that you should not converse at any length nor hold speech with your enemies, for you should bear in mind that they do no speak to you for your own good but to draw out of you what they can use to do you the greatest harm.

Speak of the achievements of others but not of your own, and do not be envious of others. Above all, avoid quarrels, for a quarrel with one’s equal is dangerous, a quarrel with someone higher in rank is madness, and a quarrel with someone lower in rank is a vile thing, but a quarrel with a folk or a drunk is an even viler thing.

And make sure that you do not praise your own conduct nor criticize too much that of others. Do not desire to take away another’s honor, but, above all else, safeguard your own. Be sure that you do not despise poor men or those lesser in rank than you, for there are many poor men who are of greater worth than the rich.

Geoffroi de Charny (1356)
A Knight's Own Book of Chivalry (Philadelphia: University of Pennsylvania Press, 2005), 70-71