I TURN SENTENCES around," says E. I. Lonoff. "That's my life. I write a sentence and then I turn it around. Then I look at it and I turn it around again. Then I have lunch.Then I come back in and write another sentence. Then I have tea and turn the new sentence around. Then I read the two sentences over and turn them both around . . . And if I knock off from this routine for as long as a day, I'm frantic with boredom and a sense of waste."

Lonoff, brilliant writer and austere relcuse, is the object of a literary pilgrimage by Nathan Zuckerman, the central character of Philip Roth's new novel. Zuckerman is a writer too: 23 years old, four stories in print, and on the make in both senses of that phrase. He has already been profiled in Saturday Review , and is volubly expert on the rivalries of those gorgeous men-of-war, the famous American Jewish writers. The reader will spend a good part of this book trying to decide who is represented by E. I. Lonoff, and who by Felix Abravanel -- a man whose charm "was like a moat so oceanic that you could not even see the great turreted and buttressed thing it had been dug to protect."

As an original for Zuckerman, we are likely indeed to think of Roth himself near the start of his career. The central issue of this novel has as its seed an unpublished story of Zuckerman's that upsets his parents extremely: a treatment of a Zuckerman family scandal, in which Zuckermans -- therefore Jews -- are revealed as adulterous, violent and greedy. Papa Zuckerman consults a capo of the Newark Jewish community, Judge Leopold Wapter, who shows the offending typescript to Mrs. Wapter. Zuckerman soon receives a questionnaire from the Wapters ("If you had been living in Nazi Germany in the thirties, would you have written such a story?"). The distress of Zuckerman's elders recalls that which greeted "Epstein," Roth's own early story about an adulterous Jew.

But the issue goes far beyond whether or not Zuckerman's story should be published. As he comes to realize in the course of the novel, he faces difficult problems of loyalty and personal identification. The pull is between his art and his origins. Thus his need for a Jewish father's endorsement from the high-minded Lonoff. And thus his need for a wife so Jewish that she will cancel out his transgressions -- a need met and disposed of in a way far too entertaining even to be hinted at.

This novel is not merely short -- The New Yorker consumed it entire in two consecutive issues -- but specifically short-story-like. The characters are few, the subject is circumscribed. Although there are flashbacks, the main action takes place within 24 hours, and within the confines of a single house. One must be grateful to the author for not padding a delicate story in order to satisfy the prevalent taste for big books.

Still, one might have been made more grateful yet. The Ghost Writer suffers, if not from paddng, at least from flaws of emphasis. Felix Abravanel for one, and Zuckerman's estranged girl friend for another, are given too much flesh for the fine bones of the plot to bear.

Another flaw lies in the large structure: we learn in the first sentence that the story is being remembered by Zuckerman more than 20 years later. This distance proves useful, allowing for such footnotes as "I was then at the stage of my erotic development when nothing excited me as much as having intercourse on the floor." The trouble is that the story ends within the memory, leaving us with a framework novel missing half a frame. We would like to come back to the mature Zuckerman -- and we would like, when we do, to feel an added resonance in the story. It would be hard to avoid anti-climax in writing such an ending, but if anyone could do it, Roth could.

And we can only believe that he could. This, his 11th book, provides further evidence that he can do practically anything with fiction.His narrative power -- the ability to delight the reader simultaneously with the telling and the tale, employing economy that looks like abundance, ornament that turns out to be structure -- is superb. He is so good in this book that even when he's bad, he's good. The Ghost Writer is a thoroughly earned triumph. It is built not only with high craft but also with base craft, the laborious turning of sentences -- what we would expect, not from a Lonoff fixed in the firmament, but from the most nervous, the least "established," the most sweatily hopeful, of Zuckermans.