In his poem “The Novelist,” W.H. Auden contrasts novelists with poets in terms of their different aptitudes. Poets can “dash forward like hussars,” but novelists must “learn / How to be plain and awkward.” A novelist, “to achieve his lightest wish,” must “Become the whole of boredom, subject to / Vulgar complaints like love.” Among the just, the novelist must be just, among the filthy, “filthy too.” This poor slave, Auden implies, must take account of the rigmarole of ordinary life, the sundry of things merely being as they are. The poet, minding his own business, sits quietly till an inspiration strikes.

By “the novelist,” Auden means the realistic novelist, perhaps someone like his friend Christopher Isherwood. In his highly suggestive and far-reaching book “How Fiction Works” (Farrar, Straus and Giroux, 288 pages, $24), the critic James Wood quotes Auden’s poem, and evidently agrees with its contrast between novelist and poet. By “fiction,” he, too, means realism. His book, like his earlier collection of essays “The Broken Estate” (1999), might well be called “How the Realistic Novel Works” or “The Novel After Flaubert.” You would not learn from these books how “Tristram Shandy” works, or “The Fall of the House of Usher,” “Dracula,” “Molloy,” or “The House of the Seven Gables,” this last a romance, a genre, as Hawthorne described it, in which the writer is free to present “the truth of the human heart … under circumstances, to a great extent, of the writer’s own choosing or creation.”

Mr. Wood does not care for such freedom. He is interested in the novel of character in which the leading figures are verifiable by appeal to the ordinary external world, the world we can’t possibly not know. In this version of fiction, which came into its own in the 19th century, characters are like persons in kind, palpable structures of forces and qualities offering themselves to be known; each is like a signature in ink which we have only to decipher.

Mr. Wood takes the privilege of the realistic novel for granted; he doesn’t worry about the ideological factors involved in his taking it for granted. He assumes that the world is as it appears to be, self-evident, unquestionable, fully present to be apprehended and annotated. He is willing to accept laws of culture as if they had the force of laws of nature. He is impatient with talk of the instability of character or the mercurial qualities that are steadied only by an arbitrary name or initial: Pierre Menard, K., Isabel Archer. Not given to rebukes, he makes an exception in favor of William H. Gass and scolds him for asserting, of Henry James’s Mr. Cashmore in “The Awkward Age,” that “nothing whatever that is appropriate to persons can be correctly said of him.” Mr. Wood finds this “deeply, incorrigibly wrong.” He is also sharp with Thomas Pynchon, in whose fictions “everyone is ultimately protected from real menace because no one really exists.” The philosophical quandaries provoked in that sentence by “really” and “exists” don’t trouble him.

But I wonder: Aren’t there figures in fiction who are not palpable, as Jane Austen’s Emma and George Eliot’s Dorothea are? What would we lose if we thought of Virginia Woolf’s Mrs. Ramsay as an apparition, which she at least once regards herself as being? I wonder what kind of fiction might correspond to Woolf’s saying, in “Moments of Being,” “we are the words; we are the music.” A notion of character would have to be very elaborate to register that impulse. I wonder, too, why Mr. Wood doesn’t interrogate the axioms by which we make our social and personal judgments; many of them are merely received notions, after all. Late in the book, he quotes Proust as saying that “our social personality is a creation of the thoughts of other people,” but he is reluctant to give that statement its weight: What would we have to say of a particular character if we thought it true? In later chapters Mr. Wood takes a deep breath and concedes — for it goes against his grain — that “the psychological novel” exists, and that it complicates the understanding of character he has earlier advanced. But even then he is anxious to get back to what he really loves in novels: sudden flourishes of perception in gestures, moments of action.

There is such a moment in [Joseph Roth’s] The Radetzky March, when the old captain visits his dying servant, who is in bed, and the servant tries to click his naked heels together under the sheets … or in [Dostoyevsky’s] The Possessed, when the proud, weak governor, von Lembke, loses his control. Shouting at a group of visitors in his drawing room, he marches out, only to trip on the carpet. Standing still, he looks at the carpet and ridiculously yells, “Have it changed!” — and walks out.

We could have done without that nudging “ridiculously.”

Style, too, is one of Mr. Wood’s favorite terms, but his sense of it is equivocal. He likes it, but he doesn’t want to have too much of that good thing. He scolds Nabokov, Updike, and, more gently, Bellow for putting their styles too blatantly on display. “Nabokov’s fiction is always becoming propaganda on behalf of good noticing, hence on behalf of itself.” Bellow is rebuked for stepping forward, in “Seize the Day,” to do Tommy Wilhelm’s thinking for him. In “Terrorist,” Updike “plants his big authorial flags all over his mental site,” to make sure he has his say even if his character, poor, limited Ahmad, can’t say much for himself.

Mr. Wood is also opposed to irrelevant detail. And to fancy styles, even though he has his own fancy styles. He is willing to “become the whole of boredom,” but every page or two he gives himself a break and flaunts his own distinctive stuff. And in his novel, “The Book Against God” (2003), he commits every one of the offenses he finds in other writers.

“How Fiction Works” is best — indeed brilliant — when it brings forward telling details: a word, a phrase, a sentence, an episode, in Dickens, Flaubert, Henry James, Jane Austen, Dostoyevsky, Proust, V.S. Naipaul, Muriel Spark, and many more. My favorite sentence is quoted from “David Copperfield,” the description of Dora’s cousin, who was “in the Life-Guards, with such long legs that he looked like the afternoon shadow of somebody else.” Many of Mr. Wood’s own sentences are nearly as good, as in summing up a perceptive contrast between Nabokov and James in relation to detail seen, he writes:

But James is certainly not a Nabokovian writer; his notion of what constitutes a detail is more various, more impalpable, and finally more metaphysical than Nabokov’s. James would probably argue that while we should indeed try to be the kind of writer on whom nothing is lost, we have no need to be the kind of writer on whom everything is found.

Mr. Donoghue is University Professor and Henry James Chair of English and American Letters at New York University. His most recent book is “On Eloquence.”