IT WAS THE popular belief that etiquette is simply a matter of acting naturally that drove Miss Manners from her comfortable chaise lounge into this business. Miss Mannners does not want people to act naturally; she wants them to act civilly.

Nowhere is the difference more evi-people naturally treat the disabled. You turn a well-meaning, good-hearted, average, sensitive citizen loose on someone who is not as able-bodied as himself, and just watch the well-meaning, good-hearted insults fly.

Why do the Temporarily Able-Bodied, as they have been called, behave so unpleasantly to others? Perhaps because the disabled have been segregated in the society. Miss Manners is not interested in hearing excuses. Miss Manners just wants you to learn how to behave properly.

Insults to the handicapped seem to be based on the absurd assumption that they are not full functioning adults and therefore - like patients or children - must do as others think best for them.

That is why people cheerfully invade their privacy, smugly shield them from the admission of sexuality, address them with patronizingly false good cheer, and blithely overrule their expressed wishes.

A typically symapthetic person will think nothing of accosting another human being, if he or she is in a wheelchair, demanding to know what is "wrong." This is personal information that someone may or may not want to volunteer. As a disabled lady of Miss Manners' acquaintance put it, "You wouldn't go up to a person ask, 'Hey, why are you ugly?'"

Nor would you lean close into the face of someone you hardly know with what she describes as "that gooey smile" with which the disabeld are often presented.

Miss Manners fails to see why a person seated in a wheelchair should be approached differently from one seated in an ordinary chair - one leans at an acceptable distance or sits nearby, and does not clutch the arm of another's chair - or why the ordinary rules of converstaion, as to taste or lack of it, should not apply. But along with the presumption about lack of privacy there is an assumption about a lack of sexuality. Miss Manners has long since learned not to make such assumptions abot anyone.

Another area of offensiveness is the matter of offering assistance. A polite person will offer assistance to anyone who seems to be in need of it, but the key word here is "offer." Disabled people often find, to their peril, that assistance is given to them after they have declined it, or contrary to their instructions on what assistance would be helpful.

If the disabled person has some aide, such as a cane or a seeing eye dog, it should be entirely under his or her control. Attempts to grab the cane arm or to pet a dog on duty are as helpful as playing with the controls of a car someone else is driving. If there is a companion accompanying the disabled individual, that assistant is not to be presumed to be a guardian. You address disabled people directly, instead of talking about them in the third person in their presence; and when you talk to a deaf person, you face him, not his interpreter.

Some leeway is allowed to children when they ask, "What is wrong with you?" or "How do you operate that thing?" But this is only because everybody understands that children don't know any better than to act naturally.

MISS MANNERS RESPONDS

Q: I would like to serve escargots at a dinner party, but I am uncertain how much equipment I have to buy to serve them properly, and also whether I can assume that other people love them as much as I do.

A: Let us be honest. You do not love snails; nobody does. They are rubbery little creatures which delight in hiding in their shells to fool you. What you love is garlic butter. The snails are merely an excuse, and a welcome one, for otherwise well-behaved people to slobber down a lot of garlic butter. Therefore, while it is nice to provide your guests with shell tongs and two pronged forks with which to go snail hunting, the really essential piece of equipment is a mop, in the form of porous bread.

Q: My wedding invitations were mailed on Saturday morning, and on Saturday night I broke my engagement. It was to have been a large, formal wedding, so there will be lots of people receiving engraved invitations which must now be recalled. How shall I do this? May I use the envelopes from the announcements.?

A: Miss Manners wishes to congratulate you on your good fortune. This is not a reference to the departure of your young man, with whom Miss Manners is unacquainted, but to the fact that you have the engraved announcements at your disposal. Miss Manners suggests you correct them with a pen, so that they will now read:

Mr. and Mrs. William Joel Perfect have the honour of announcing that the marriage of their daughter Daffodil Louise to Mr. Jonathan Rhinehart Awful III will not take place

Q: Would you please give me the correct etiquette on speaking or greeting people when entering a room of people and when meeting on the street. Should the person entering the room speak first? Should the youngest speak first, respecting their elders? I have relatvies in their late teens and also young adults (married) who will never speak unless spoken to first. I was brought up different.

A: Even Queen Elizabeth has given up the rules about speaking first, and she was brought up different, too. Several years ago, when she visited America, she greeted with regal silence anyone who presumed to speak to her before being spoken to; last year, while she was not yet up to calling out "Howdy," she, at least returned all greetings. Miss Manners feels it is always gracious to address another person civilly and to acknowledge civil addresses, and is pleased to see anyone master this ability, whatever her upbringing and however late in life.

Felling incorrect? Address your etiquette questions (in black or blue-black ink on white paper) to Miss Manners, Style Section, The Washington Post.