“When you have blown your nose, you should not open your handkerchief and inspect it, as though pearls or rubies had dropped out of your skull. Such behavior is nauseating and is more likely to lose us the affection of those who love us than to win us the favour of others.”
“It is not polite to scratch yourself when you are seated at table. You should also take care, as far as you can, not to spit at mealtimes, but if you must spit, then do so in a decent manner. I have often heard that people of some countries are so demure that they never spit at all, and we might well refrain from doing so for a short time. We should also be careful not to gobble our food so greedily as to cause ourselves to get hiccups or commit some other unpleasantness, like a man who hurries so much that he makes himself puff and blow, which annoys everybody else.”
“No one must take off his clothes, especially his lower garments, in public, that is, in the presence of decent people, because this is not the right place for undressing. Besides, it might happen that the parts of the body which are normally hidden should be laid bare, and this would embarrass both the man himself and the onlookers.”
– Giovanni Della Casa in Galateo or The Book of Manners (1558); painting: Monsignor Giovanni Della Casa (1544) by Jacopo Pontormo, from the National Gallery of Art, Washington, D.C.