TOBIAS WOLFF knows a lot. He knows about men and women and children, and about America in its variety. His people are kids, soldiers, wives, successful in business or failed in art. They're devotees of love, of drugs, of technology. Wolff's taste for experience seems, as a major writer's should seem, promiscuous.

All 10 of these stories are told in the third person. This narrative mode permits an exterior view of even the central figure, which seems to be why Wolff employs it. He's disinclined to tell stories from the inside out, to present a world through the thoughts and feelings of a viewpoint character.

Instead, Wolff tries to create windows on the soul through speech and action. In pure form, that is the way of drama. In fiction it tends to be awkward, artificial, inefficient, and extraordinarily difficult.

Yet at his best Wolff turns the handicap into an added grace, making his method appear easy or even inevitable. The central character of "Coming Attractions," 15-year- old Jean, works in a movie theater. After closing up for the night, she's waiting alone for her boss to come and drive her home.

We see inside her scarcely at all. But the pathos of her life, and the heroism with which she meets it, emerge through phone calls that we hear her make, followed by a series of inspired events.

This story, like several others collected here, combines a traditional emphasis on character with a contemporary looseness of plot. There's no clear forward march, no resolution, no comes-to-realize. Helpless to change her circumstances, Jean wages war within them. She is an existential heroine, who continues to act, no matter how ineffectively or irrelevantly, and thus to be. At the end, though nothing has changed in her, something has in us.

"The Poor Are Always With Us," another grand story, takes place among computer engineers in Silicon Valley. The milieu is authentic: protagonist and antagonist meet when they bring their Porsches in for servicing. The audacious plot turns on a wager, the consequences of which change several lives. Here again, the inner world is illuminated through word and deed.

OTHER STORIES, less lustrous, shine in places and parts. "The Missing Person" follows the trajectory of Father Leo, who longed to be a missionary in Alaska, as he sinks through level below level of a demeaning career. He's spiritual advisor to a gaggle of hip nuns -- one a disc jockey -- who call him "Padre" or just "Pod." Equally memorable is Krystal, the heroine of "Desert Breakdown, 1968," who loves the word "never" because it reminds her of Beethoven shaking his fist at the heavens.

Still, many of these stories do not seem adequately lit. Collectively, they show the limits of what exterior signs can tell us of people's brains and viscera. Only a partial humanity percolates through action and speech. Not even a writer as good as Wolff can eschew he thought and he felt forever.

The distress that his method creates is seen first of all in dialogue. Speech in fiction, in order to be efficient for the author's purposes, needs to be inefficient for the characters'. Wolff's dialogue falls easily into addresses, so eloquently explanatory that they look less like speech than like writing.

One sometimes feels, eerily, that the characters are aware of the reader's need for information. At times the ostensible viewpoint character becomes little more than a conveniently placed eye and ear, used by the author to let us eavesdrop on a story- within-the-story.

In "Our Story Begins," a busboy walking home from work stops at a coffeehouse. There he overhears a story told by one patron to another -- a story that continues for nine pages. Afterward, completing a kind of narrative sandwich, the busboy continues his walk home. He has (so far as Wolff lets us know) no response whatever to the overheard story. Any connection between it and his own story is obscure.

"Leviathan," a close to generic story of four friends gathering for cocaine and confessions, lies at the nadir of this collection. The anecdotes are boring, the action thin. Yet even here, Wolff does so much well that his gifts are continually evident.

Those gifts are lavish. His ear is sharp for every kind of speech. He can be very funny. He can be lyrical. His people display consistency and irrelevance -- that odd blend of the mechanical and the random that we embrace as free will. His decorative surfaces turn out to be weight-bearing. His details, innocently planted, germinate. Back in the World is a striking and an exciting collection by a writer unusually fine.