Is it a study hall where rude people are breaking the rules by talking too loudly to one another and on their telephones?

Or is it a social watering hole where rude people are ruining the convivial atmosphere by spreading out their work?

Or is it an office extension where networking and conferences take precedence over both silence and loud chatter?

The modern coffeehouse has not decided which of these it wants to be. Rather, it appears to be waiting for its clientele to decide while it tries to figure out who drinks the most coffee -- students trying to stay awake, businesspeople nervously trying to close deals or sociable sorts trying to prolong the party.

As a result, such places are often crammed with three factions, all of whom tell Miss Manners, with equal indignation, about the bad manners of those other people who are ruining the proper atmosphere of the place.

And both sides are fueled with caffeine.

Historically, coffeehouses have served all of these purposes. In the mid-17th century, Samuel Pepys was hanging out in coffeehouses both to hobnob with his Restoration pals and to do paperwork for his job as an administrator of the Royal Navy.

Lloyds of London started as a coffeehouse frequented by mariners whose need for insurance surfaced from their conversation. The 18th-century figure most associated with coffeehouses, Dr. Johnson, a tea drinker who didn't even like coffee, regularly frequented a coffeehouse for conversation with writers and painters who did. In the mid-20th century, a revival of coffeehouses attracted students, poets and folk singers.

And in the 21st century, coffeehouses took up the important function of ensuring the continuity of the human race.

Now that romantic alliances are no longer fostered by the participants' family and social networks, the coffeehouse has become indispensable as a safe haven to check out strangers culled from the Internet as prospective romantic partners.

Miss Manners is by no means opposed to hybrid commerce.

Not only does she approve of venues for spontaneous socializing, but she is delighted to find business picking up the slack caused by a decline in private entertaining.

She is opposed only to public warfare among those operating from different notions of the prevailing rules.

Since bookstores started attaching cafes and developing reading corners, they, too, have been known to inspire conflicts between readers and talkers. An added element is the children's book section, made into a stopping place for those who are able to manage literature and noise simultaneously.

Miss Manners understands how reluctant proprietors are to chastise any of their clients, but reminds them that this is preferable to the melees that occur when the clients go after one another. It would seem reasonable that public accommodations not enforce silence, but be prepared to step in when necessary and say, "Excuse me, but I wonder if you would be kind enough to keep your voices down somewhat." And, for that matter, provide directions to the public library. Feeling incorrect? E-mail your etiquette questions to Miss Manners (who is distraught that she cannot reply personally) at MissManners@unitedmedia.com or mail to United Media, 200 Madison Ave., New York, N.Y. 10016.

(c) 2005, Judith Martin