Columnist Kilpatrick on language; The Writer's Art, by James J. Kilpatrick. Fairway, Kan.: Andrews, McMeel & Parker Inc. 299 pp. $14.95.

One approaches fall with anticipation. One watches the children, conspicuous in new clothes, some shy, some gregarious, waiting for the big yellow bus. One senses that something abstract has entered the atmosphere, just as surely as the air has a new edge, a new transparency.

The new element, after the languors of summer, is no doubt the element of discipline. So much education is a matter of reducing feelings to symbols, of disciplining the warm chaos within! What ripens toward fall is our readiness to give up the summer promises of boundless possibilities for a few well-defined ends.

So much education is a matter of writing it down.

And what is the image we cherish of the writer? Not the emaciated romantic, slave to a demon muse, but an ordinary person with clean hands and a clear head, with sharp pencils, white paper, and a comfortable space in which to work. And a nose for the business at hand.

The nose reminds us that a good writer is a critic. And if you feel I have just left you behind, behold: James Jackson Kilpatrick, now, at 63, pretty much retired in Rappahannock County, Va.; a syndicated columnist, whom George Will calls ''a Jeffersonian, Virginia, small-government, free-market, classic conservative,'' and who, according to September's Vanity Fair, still belongs to the Op-ed Set - this man Kilpatrick has written a book just for you and me.

In a marketplace overflowing with short books on how to write well, Mr. Kilpatrick, whose column is used by 512 papers, speaks from experience, in a book no shorter than it should be, seeing it is from the hand of one of the master journalists of our times.

What claims our attention here is one writer's experience of the language and of the people who use it. More than any other master writer who has preserved the essence of his craft in a handbook, Mr. Kilpatrick conveys the experience of what is, after all, a sometimes distressingly abstract affair. He begins by saying, ''Ours is a beautiful language, beautiful to speak and to hear, beautiful to read and to write.'' Later on he says, ''As writers, let us look at everything very hard, so it will stay in our heads for always.''

After we look hard, we write. To write, he makes clear, we have to collect words. With characteristic precision, he describes the looking as sensuous, the collecting as intense. Judging from the specimens of word usage he has collected , some nearly perfect, some ludicrously wrong, Mr. Kilpatrick's intensity has paid off. Years of judgment lie behind his exhibits of good English, as when he directs us to read Rebecca West, vintage '46 (her dispatches from the Nazi war trials).

As for the exhibits of what goes wrong, there is no want. Mr Kilpatrick's ear, like his nose, is sensitive; the longest chapter by far is devoted to usage. A paragraph on the word ''pinch hitter'' concludes, ''... the vocabulary of baseball ought to be used as we use other vocabularies, with tender loving care.''

But almost all books of this sort have lots of examples of what not to do. Mr. Kilpatrick's is special because in it he tells us what we ought to do. In a masterly section entitled ''We must keep our instrument properly in tune,'' he quotes Roger Rosenblatt's essay on a plane crash (from Time magazine), a passage from Ken Follett, examples from John D. MacDonald and Dick Francis, E. B. White, and, yes, James J. Kilpatrick himself. He has kept his instrument in tune for many, many years, and the result is a tone of rich sonority, cunning flexibility , and unembarrassed elegance.

''The Writer's Art'' is, then, adult fare. No, we don't have to eye the schoolchildren enviously anymore. We, too, can face the fall with anticipation; we, too, can learn from our experience. That is, if we sit down and work on our writing, with master Kilpatrick nearby ready to console, rebuke, and inspire.