"Since it is the case that you are now just beginning that journey that I have for the most part as you see completed, that is, the one through mortal life, and loving you so very much as I do, I have proposed to myself--as one who has been many places--to show you those places in life where, walking through them, I fear you could easily either fall or take the wrong direction." So begins Galateo, a treatise on polite behavior written by Giovanni Della Casa (1503-56) for the benefit of his nephew, a young Florentine destined for greatness.             In the voice of a cranky yet genial old uncle, Della Casa offers the distillation of what he has learned over a lifetime of public service as diplomat and papal nuncio. As relevant today as it was in Renaissance Italy, Galateo deals with subjects as varied as dress codes, charming conversation and off-color jokes, eating habits and hairstyles, and literary language. In its time, Galateo circulated as widely as Machiavelli's Prince and Castiglione's Book of the Courtier. Mirroring what Machiavelli did for promoting political behavior, and what Castiglione did for behavior at court, Della Casa here creates a picture of the refined man caught in a world in which embarrassment and vulgarity prevail. Less a treatise promoting courtly values or a manual of savoir faire, it is rather a meditation on conformity and the law, on perfection and rules, but also an exasperated--often theatrical--reaction to the diverse ways in which people make fools of themselves in everyday social situations.             With renewed interest in etiquette and polite behavior growing both inside and outside the academy, the time is right for a new, definitive edition of this book. More than a mere etiquette book, this restored edition will be entertaining (and even useful) for anyone making their way in modern civilized and polite society, and a subtle gift for the rude neighbor, the thoughtless dinner guest, or the friend or relative in need of a refresher on proper behavior.