From The New York Times:
In Renaissance Europe, Italy was Etiquette Central, attracting all the fascination and ridicule that go with that honor. English readers in the early 17th century assumed Tom Coryate, a professional jester turned travel writer, was joking when he reported that Italians did not attack their food with hands and hunting knives as did normal people, even normal royalty. Those finicky Italians wielded forks, a nicety that did not become common in the rest of Europe for another two centuries. Italian princes, courtiers and patricians sought instruction on improving their behavior toward others. That was not a goal that often appeared on the to-do lists of the power elite elsewhere. Of the three most prominent surviving Italian books on conduct, “Galateo,” by Giovanni Della Casa, published in 1558 and now out in a new translation by M. F. Rusnak, is the one that promotes civilized manners for their own sake. The respective aims of Baldassare Castiglione’s “Courtier,” which recommends sprezzatura, the Renaissance equivalent of being cool, and Machiavelli’s “Prince,” devoted to realpolitik (and therefore stressing effective, rather than genial, behavior), are admiration and glory. Although “Galateo” is addressed to a favorite nephew, only in passing does Della Casa, an ecclesiastical diplomat, mention career advancement as an incentive to learn the ways of society. Nor, although he was an archbishop, albeit a worldly one who wrote salacious poetry, does he evoke God as his source, as did the earliest writers of rules of behavior. Rather, as a classics scholar, he uses an aesthetic standard.
Della Casa’s message is: Don’t be disgusting. Pretty much everything that comes out of a bodily orifice meets his definition of disgusting — so much so that the mere sight of someone washing his hands would upset people, as their minds would leap to the function that had necessitated that cleansing.