James Wood, 42, is from the U.K. He's tall, walks fast, drives a white Mini Cooper, speaks eloquently and enjoys a nicely tended garden.

It's after lunch, and he's walking (quickly) down Brattle Street in Cambridge, Mass., when he spots two kids playing on the immaculate front lawn of a stately house. “Look at them,” he says. “They have no idea how lucky they are.” A block later, he steps up on tiptoes to peer over a brick wall at some hidden greenery. “Lovely,” he says. “I love gardens. I like to sit in them.”

He is, however, not a gardener—he doesn't like the labor. And besides, he's too busy lecturing at Harvard and being the pre-eminent critic of contemporary English-language letters to pick up a watering can. It should also be noted that he is the fiction critic at the New Yorker, is married to the novelist Claire Messud (they have two children), coined (and sort of destroyed) the school of “hysterical realism” and is the author of two books of criticism, a novel (The Book Against God, Farrar, Straus & Giroux, 2003) and what he calls his “little book,” How Fiction Works (FSG). The title tells the book's story. It's a slim volume and lacks a menacing subtitle, but in the book's 208 pages, Wood lays out the dos and don'ts and whys and why nots of narration, character, dialogue, narrative and detail.

The book's format and informal tone, Wood says, is a result of lecturing at Harvard and teaching a special master's class at Columbia, and it also outs him as not strictly a critic. Here is a man who really, really loves fiction that works and even uses exclamation points. There are four in his text, and to hear Wood talk about it, you might think that the British press would have liked to impale him on one.

“In almost every case in Britain, and maybe I hadn't realized it was a tick in the book or an irritation, but they said, 'Why does he have to go into raptures? It's pompous.' Someone said it's like belles lettres from the 1890s. Someone else said it's like dispatches from the world of beautiful letters. An academic said, 'it's embarrassing that he gets so worked up.' ”

When the book's very positive reviews are brought up, Wood acknowledges them, briefly, and, then, like any writer, dials in on the bad press again. (On his novel: “There was a certain kind of happiness to say, 'Wood demands masterpieces of novels. Is his own book a masterpiece? No, it isn't. Let's all pile in and have a great laugh at that.' ” On the catty blogosphere: “For a while I got caught up in the arguments, and I would actually weigh in. You can't do that, and it's surely a bad sign that it only ever occurs to one to do it at three in the morning when one is depressed.”)

So, unlike most critics, Wood knows what it's like to both deliver and receive pans. But he says he takes no pleasure in hurting people's feelings. “I think as I get older, I don't know what this is about, but I think as I get older I'm more aware of the danger of being involved in an occupation that hurts people's feelings. I agree that, on the hierarchy of sins, it's not very high, but still, is that what you want to do? I often blithely like to quote the Kingsley Amis thing, and I try to live by it myself, that a negative review should spoil your breakfast but not your lunch. But I know perfectly well that a bad review spoils more than my lunch—my dinner and a few weeks of dinners.”

Professionally, he's “closed the door on the whole hysterical realism thing” and has been “getting more engaged in contemporary American writing by people younger than the DeLillo crowd.” On the docket: following in Edmund Wilson's footsteps and taking on more than literature. (See “Holiday in Hellmouth” in the June 9 New Yorker.) “I imagine I'll stay a critic,” he says, “but there might be different ways of writing about things.”