IMAGINE HOW astonished Miss Manners was to be asked about singles bars. Why, Miss Manners has never even set foot in a sandwich bar, let alone a singles bar, and wouldn't know what to order. Romance is all very well, but it certainly has nothing to do with civilized behavior, which is Miss Manners' passion.

Nevertheless, the question seemed a sensible one: "Now that the segregation of people by age and marital status has made the personal introduction obsolete, how does Miss Manners meet gentlemen of honorable intentions without resorting to such degrading alternatives as singles bars?"

To begin with, let us leave Miss Manners herself out of this, and also the intentions of gentlemen of her acquaintance. It was not Miss Manners who raised the problem. She does acknowledge, however, that it can be a legitimate one.

She is also forced to acknowledge, on second thought, that it is, indeed, a social, rather than a romantic, problem. As the question states, the society is segregated now by age and martial status. There are two quite distinct classes of people today, and they are not Rich and Poor, but Looking and Not Looking. The overwhelming occupation of the population seems to be looking for a mate, which leaves those who are mated nothing to do but macrame. That is why the latter are so anxious to discuss what is wrong with their relationships: So that they can break up and start all over again.

There must be a solution to all of this, and Miss Manners has it. The singles must stop being so single-minded. Those who are looking must stop looking as if they are looking, so that others will have to look after them.

Perhaps that is not clear. Well, in an ordered society, singles as well as doubles, are part of a network of social ties and obligations. Single people must then invite happily married former roommates to dinner, visit ailing great-aunts, take the children of friends to the Museum of Natural History and pay calls on hospitalized relatives. Right now, they tend to skip such attentions on the grounds that there is no pay-off.

What they don't know is that they will then give a new interest in life to the recipients of these attentions. The former roommate's spouse will produce, on the return dinner, an about-to-be-divorced friend whose re-entry into the market hasn't yet been posted. The great-aunt will scheme to pair her grand-niece with her late husband's grand-nephew. The children will reciprocate by issuing invitations to dreadful school plays directed by undreadful, unmarried teachers. The patients will gather up the strength to ring their bedside bells to summon eligible doctors and nurses.

This is the way the society used to function. Did you ever hear of a singles' problem before the singles decided that they would solve their own problems? MISS MANNERS RESPONDS

Q: My leg fell asleep at a dinner party. I didn't want to make a fuss, and so I just sat there pinching it, but that didn't help, and I was in agony. Would there have been a polite way to handle this problem?

A: Some medical emergencies take precedence over the ordinary rules of polite behavior. It depends not on the seriousness of the illness, but on how socially acceptable it is. Nothing would excuse your head's falling asleep, but the leg might squeak through. You could have waited for a pause in the conversation, announced calmly to the hostess, "I'm afraid my leg seems to have gone off again," and, with her permission, amused the guests by stomping around the dining room table until you had effected a cure.

Q: I always answer my own telephone, and I get furious when I am told to "Hold on, please," and am the left dangling. Mind you, this is from people who are calling me -- I may not even want to talk to them. Should I just hang up, or what?

A: Hanging up is rude. Say, "I'm So sorry I answered my telephone at an inconvenient time for you," and then hang up.

Q: I am originally French, and I was taught to say that I am enchanted to meet people when I am introduced to them. My wife says this is not done in this country. What is wrong with it?

A: We are a blunt and cautious people. Enchantment may or may not develop after an introduction, but never during it. What is wrong with saying that it does, is that you are then left without a follow-up.

Q: Where does one wear a hat these days?

A: Same as always: On the head. (Whoops. You'll have to pardon Miss Manners, who occasionally gets giddy after a full day of this sort of thing.) The proper answer is that the occasions for wearing hats, for both men and women, are the same as always, but the purpose is the opposite. One used to wear a hat with daytime clothes to be conservative; it is now done to be shocking. Miss Manners finds cocktail hats especially effective for the new purpose.