SOME OF THESE TALES - nine stories and a novella - are set in childhood, others in the military: worlds that Andre Dubus shows to be remarkably alike. Gang spirit, the yoke of authority, simmering violence, dreams of glory - these the child and soldier share. Given their passions and their fetters, both figures make strong protagonists. And given their lives' diagrammatic daily order, their exclusion from society at large, their scheduled metamorphoses into adult and civilian, how well they suit the shape of short fiction.

But choosing a helpfully ordered world is only a preliminary; stories stand or fall because of how soundly - not where - they are built. And every line of this book is both honestly felt and shaped with care. There is never a wisp of cosmetic obscurity, no sermonizing and no coyness, no self-preening prose.

The novella, "Adultery," stands far above most of the stories. Told mostly from a young mother's point of view, it portrays the slow collapse of her marriage while she and her husband each have a series of love affairs. The power of the story depends, not on any clever innovations of plot, but on something finer: the author's ability to notice what the rest of us merely see, to show us what important truths we never knew that we knew - and never could have known that we knew if we hadn't read this. Of the relationships between men and women, men and men, women and women, here is a wealth of understanding.

"The Shooting," the best of the short stories, turns on an incident of violence, but even here the force of the fiction derives from character, not plot. As Rust Hills once observed, plot isn't simply what happens; it's what happens to somebody. What makes it matter to the reader is the fact of its mattering to the central character. Wisely, this is what Dubus finally cares about: not a man's actions, however dramatic, but their complex effect upon him forever after.

The several stories dealing with childhood are the least successful - in no way bad, merely weak - and seem like early work, rehabilitated to fill out the volume. The final effects they aim at are simply too slight, too tentative. And indeed, if many of these ten pieces share a shortcoming, it has to do with final effect. The ending of a story should confer shape, wholeness. It should be a kind of spotlight, shining back over the story and revealing its unity, the necessity and beauty of its arrangement, its cumulative force. Here Dubus's touch is uncertain; sometimes the stories trail off almost arbitrarily.

Nor is it only in their endings that some of these stories seem unfinished. Nailheads have been left showing where certain materials are joined, almost as though two separate stories had been hammered together. The handling of time tends to be awkward. In the childhood stories especially, the virtue of simple writing has sometimes been carried to excess.

But, more than most books, this one shows us a writer in transit, who travels far while we watch him. The stories appear to be printed in roughly the order of their writing for as we read on they grow richer, more mature. The dialogue becomes as accurate as a tuning fork. The eye for detail, precise and vivid and revealing, grows continually sharper. Above all, the examination of character grows more and more intimate, profound, absorbing, ever fuller of critical wisdom and uncritical love.

"Adultery," the novella that concludes, indeed crowns, the book, is not unflawed; here again there are problems with structure, including the ending. And yet here we have entered the world of highest artistry toward which the stories windingly lead. Perhaps it suggests a largeness more important than length that the novella is set, not in the stories' enclosed worlds of childhood and the military, but in society at large, where our medals are invisible and spankings are always of the spirit. Writers will envy it, readers will read it again. It comes from an author of whose expanding powers one does not sense a limit.