Most literary reputation is fragile and fleeting, and the reputation of poets especially so. Their stock is traded on a Nasdaq of singular cruelty and volatility. We still read Hemingway and Fitzgerald, for example, but who reads Edna St. Vincent Millay, in her lifetime just as celebrated as her two contemporaries? Almost as famous was Edwin Arlington Robinson, whose best-selling Arthurian trilogy -- "Merlin," "Lancelot" and "Tristram" -- is something that few readers now would want to linger over, particularly if they were hoping to stay alert enough to drive or operate heavy machinery.

Sometimes death is the making of a poet's reputation, as in the case of Sylvia Plath, the details of whose suicide -- the towel under the door, the unlighted oven hissing gas, the sleeping children in the next room -- lent both poignance and a certain creepy glamour to her posthumous work. Sometimes a poet dies, spends a term in limbo and then is resurrected in a different guise altogether. This is what happened to Robert Frost, who at the time of his death in 1963 was generally considered to be a New England folkie -- the homespun bard of stony walls and snowy evenings. In 1977, the third volume of Lawrance Thompson's biography suggested that Frost was a much nastier piece of work than anyone had imagined; a few years later, thanks to the reappraisal of critics like William H. Pritchard and Harold Bloom and of younger poets like Joseph Brodsky, he bounced back again, this time as a bleak and unforgiving modernist.

But most of the time, death for poets is what it is for the rest of us -- the beginning of that slow, inexorable process of being forgotten. Take the case of Robert Lowell. When he died, in 1977, Lowell was by far the most famous American poet of his era. The only figure of comparable renown was Allen Ginsberg, but Ginsberg was never embraced by the critics the way Lowell was; with his ohm-ing and his finger cymbals, Ginsberg had become a kind of self-caricature. Lowell was cool, but he was also dignified, and his reputation seemed secure and indelible. Within a couple of decades, though, he had all but fallen off the map. His books slipped out of sight, his poems disappeared from reading lists and course catalogs. Almost nobody talked about him -- especially in the writing programs, where younger poets go to learn what they self-consciously call their "craft." Increasingly, Lowell looked like the end of a line and the last of his kind -- the Great American Poet (White Male Div.).

How are the mighty brought so low? In Lowell's case it was probably inevitable. For a while, he loomed so large that he crowded everyone else off the stage. There was a time in the mid-60's when you couldn't pick up the paper without reading about Lowell. When he declined Lyndon Johnson's invitation to read at the White House in 1965, it made Page 1. Lowell actually took Shelley's wishful pronouncement seriously, believing that poets were the unacknowledged legislators of the world. He was a familiar figure at protests against the Vietnam War, and also on the campaign trail, where he served as unofficial consigliere to Eugene McCarthy (a closet poet himself).

Lowell had the good fortune to come of age at a time when poetry hadn't completely gone out of fashion. Eliot and the religion of modernism were still in high regard, and it was even possible for a poet to be awarded a photo spread in Life magazine, as Lowell was in 1947. He was also lucky in his genes. He was a Boston aristocrat -- a Winslow on his mother's side and, on his father's side, connected to the Cambridge Lowells, one of New England's formidable ruling clans. Lowell looked like a poet (White Male Div.). He was big and imposing, with handsome, almost Roman features that were never entirely obscured by those nerdy black glasses he often wore. As he aged and let his hair grow long, he came more and more to resemble someone out of the Old Testament. He also sounded like a poet, intoning his verse in an accent that was part Boston Brahmin, part Southern drawl (an overlay acquired from his teachers). Most of all, Lowell wrote like a poet, in language that was grand, sonorous and memorable. If you were an English major in the 60's, you probably still remember the first time you read "For the Union Dead," with those excoriating last lines:
. . . Everywhere,

giant finned cars nose forward like fish;

a savage servility

slides by on grease.
Even the dullest among us knew that this was the genuine article.

But fashions change, and waiting in the wings for Lowell to get off the stage were quieter, less stentorian poets like John Ashbery (whose style was more elusive and almost surreal) and James Merrill, who was more elegant and witty. The poet whose reputation most benefited from Lowell's demotion was his friend Elizabeth Bishop, the contemporary poet he most admired and who most influenced him. Hers was a case of a poetic stock that had been severely undervalued for years -- in part because she was the opposite of Lowell: private, retiring and unprolific. Though Bishop herself hated identity politics of any sort, her reputation also benefited tremendously from the groundswell of interest in feminist and lesbian poets, and on most campuses now she has far more stature than Lowell. She is indisputably part of the canon, while his ultimate ranking is still uncertain.

Even during Lowell's lifetime his reputation had a dark side: drinking, affairs, public outbursts. To a point this did him no harm; we like our poets to be tarnished angels. But in 1973, Lowell alienated much of the literary community with "The Dolphin," a volume of poems describing his affair with the British novelist Lady Caroline Blackwood and the breakup of his second marriage, to Elizabeth Hardwick: not only did the volume explicitly refer to Hardwick and to their daughter, Harriet; it even quoted some of Hardwick's personal and imploring letters. Everyone to whom Lowell showed the manuscript counseled against publishing it, but Lowell somehow thought he could lessen the sting by simply rearranging the order of the sections. He was crushed by the hostile reception it got.

Lowell and Blackwood married a year before "The Dolphin" came out, and the union proved to be toxic and combustible. "I'm manic," Lowell said once, "and Caroline's panic." What began as bliss ended in exhaustion and distrust, and a nightmare for hotel chambermaids on both sides of the Atlantic as the couple left behind a trail of broken glass, bloody towels and empty vodka bottles. Worn out and in poor health, Lowell eventually left Blackwood and died in a cab on his way back to the long-suffering Hardwick. (He was clutching a portrait of Lady Caroline.)

The damage to his reputation was compounded in 1982 with the publication of Ian Hamilton's biography. While not unsympathetic to Lowell, Hamilton revealed a number of secrets that had been known only to intimates -- not only was Jean Stafford's nose shattered, for example, in an accident caused by Lowell's reckless driving (that was legend), but after they were married, in 1940, he socked her and broke the nose again. The last half of his book becomes a sad and unrelenting catalog of the cycle of mania, breakdown and hospitalization that dogged Lowell all his life. That he had been treated for mental illness was no surprise to his readers. A stay at McLean Hospital is the subject of his famous poem "Waking in the Blue," the one whose third stanza begins:
This is the way day breaks in Bowditch Hall at McLean's;

the hooded night lights bring out "Bobbie,"

Porcellian '29,

a replica of Louis XVI

without the wig -

redolent and roly-poly as a sperm whale,

as he swashbuckles about in his birthday suit

and horses at chairs.
But Hamilton's biography made it clear that mental illness -- its manic outbursts (Lowell would send cables to the pope, conduct operas while standing at his seat in the audience), its depressive aftermath -- was a more constant part of his life than anyone except his closest friends knew, and they of course also remembered the many happier, saner moments, which the biography inevitably tended to slight.

If you were going to orchestrate a poet's reputation, the biography would come out after a hefty selection of the poet's letters, perhaps, and certainly after a big, career-capping volume of the poet's collected work. The collected volume is the equivalent, in the poetry world, of the major museum retrospective; it's also what keeps poets in the syllabus and on the reading lists. The model here is the posthumous career of James Merrill. Whatever his biography (which is in the works) does or doesn't reveal about Merrill, it will be in the context of the sumptuous volume of his collected poems, which came out just six years after his death, in 1995, and demonstrated that Merrill was an even more considerable poet than had been thought.

In Lowell's case, that collected volume, so necessary to solidifying a poet's reputation, is only just now making its way to the shelves, edited by Lowell's literary executor, Frank Bidart, and by David Gewanter. There are several reasons for the 25-year delay, chief among them that Lowell, like Wordsworth and Auden, was a tireless and obsessive rewriter. Revising for him wasn't just an afterthought but an essential part of the creative process, and in a sense none of his poems were ever truly finished. Just assembling and sorting through the various texts was an exhausting editorial enterprise. Then, though this had not been part of the original plan, Bidart decided that the poems needed to be annotated. But finally what delayed the "Collected Poems" was the same thing that kept Penelope at her loom. The longer Bidart worked on the project, the more reluctant he was to finish. "I loved Lowell -- he mattered enormously," Bidart said recently. "And in a funny way to end this book was like losing him all over again."

In fact the book restores him -- not Lowell the basket case but Lowell the master. And the "Collected Poems," if you read it more or less in chronological order, supplies another kind of biography, the story of how a great poet finds and then refines his voice. Unlike Merrill, whose early poems were precociously (almost eerily) polished and proficient, Lowell was not a natural. He decided to become a poet while still in prep school, but his ambition far outstripped his early accomplishment. Among other things, he disdained the advice of one of his teachers, Richard Eberhart, that poetry ought to give pleasure. His early work, stiff, labored and artificial, was not much fun at all, and it was hardly a blessing for Lowell's poetry when in 1941 he briefly but fervently converted to Catholicism (so fervently, according to Ian Hamilton, that he stopped sleeping with his wife at the time, Jean Stafford). Lowell's first book, "Land of Unlikeness" (published in 1944), contains some promising poems, but also lots of dreadful, Hopkins-inspired verse:
Oh, if soldiers mind you well

They shall find you are their belle

And belly too;

Christ's bread and beauty came by you,

Celestial Hoyden, when our Lord

Gave up the weary Ghost and died. . . .
Lowell's next two volumes, "Lord Weary's Castle" (for which he won the Pulitzer Prize in 1947) and "The Mills of the Kavanaughs," which came out in 1951, were notable improvements but not exactly easygoing. Written mostly in enjambed blank verse, these poems stomp on the sound-effects pedal (lots of alliteration and piled-up consonants) and are so dense in their layers of reference that you don't so much read them as unpeel them, layer by layer.

Lowell's great breakthrough came in 1959 with the publication of "Life Studies," a book that transformed American poetry. Lowell dropped the pentameter line in favor of one that was shorter and freer, and he discovered so-called confessional poetry: he wrote about his family and his ancestors, about his own breakdowns and depressions. What resulted was poetry that was both formal and colloquial (and even funny), both personal and public, as Lowell turned himself into a kind of midcentury Everyman. The poems were memorable in a way that so much contemporary verse is not, because of the way they managed to combine language that was genuinely "poetic" with the ease and naturalness of everyday speech:
One dark night,

My Tudor Ford climbed the hill's skull;

I watched for love-cars. Lights turned down,

they lay together, hull to hull,

where the graveyard shelves on the

town. . . .
These and the poems that followed in "For the Union Dead," five years later, were the ones that so many English majors thrilled to, and that made Lowell, in his way, the rock star of American lit -- the heartbreaking poems about Lowell's father, humming "Anchors Aweigh" in the bathtub or swaying, "bronzed, breezy, a shade too ruddy," after downing his bourbon old-fashioned; the sexy poems about his marriage to Elizabeth Hardwick:
. . . Oh my Petite,

clearest of all God's creatures, still all air and nerve:

you were in your twenties, and I,

once hand on glass

and heart in mouth,

outdrank the Rahvs in the heat

of Greenwich Village, fainting at your feet -
Had you stumbled on these poems from someplace else on the assigned reading list, you might have been taken aback. They weren't ostensibly about the great poetic subjects: mortality, good versus evil and beauty and truth and the like. They were about getting along with your relatives, about being horny and depressed, about waking up in the loony bin. But they talked about these subjects in language at once so natural and so elevated, so classical and colloquial, that they invested ordinariness with a kind of grandeur.

If Lowell had never published another word after "For the Union Dead," he would still deserve a place in the anthologies, but in fact he went on to write a great deal more -- so much that the critics and scholars, those who haven't written him off, are still trying to come to grips with it all. In 1973 alone, he published three separate volumes of what he termed sonnets -- unrhymed 14-line poems -- and then toward the end of his life, in "Day by Day," there was a last, late flowering of poems in a relaxed and conversational meter. Not all of these are great, the sonnets especially. Some are boring, some almost impenetrable, but they are written with a conviction that now seems almost quaint. Unlike so many contemporary poets, Lowell never wrote poetry about poetry, or worried about the insufficiency of words to stand for what they signify.

Lowell may have belonged to the last generation to believe seriously in the poetic vocation. His friends and colleagues, all born around World War I, included Bishop, Randall Jarrell, Delmore Schwartz, John Berryman and Theodore Roethke. They didn't imagine themselves teachers of creative writing who would turn out the occasional slim volume; they saw themselves as the heirs to, and the equals of, Yeats and Eliot. (Lowell on occasion even compared himself with Milton.) They believed, as Eileen Simpson, Berryman's first wife, wrote in her memoir, "Poets in Their Youth," that poetry must be the "ruling passion" of life.

They were all a little nuts, of course -- or, in the case of Lowell and Schwartz, more than a little sometimes. Except for the teetotaling Jarrell, they were all alcoholic, and they smoked like chimneys. Berryman killed himself, and Jarrell most likely did. The rest died, in poor health, long before they should have. Major American poet, mid-20th century -- it's not a job description or a lifestyle that you would wish upon anyone.

Part of their misery was that so few people were paying attention. Poets have always complained about the smallness (and unfitness) of their audience, of course, and in fact the mid-20th century was not such a bad moment for being a poet in America. It was a far better moment than the early 21st century is -- when poetry has become an art form with more practitioners than actual readers. But already back then, Berryman and Schwartz, in particular, were complaining bitterly about the poet's insignificance in American culture, about a decline in readership and in critical attention. The poet must dedicate himself to poetry, Schwartz wrote, even though "no one else seems likely to read what he writes; and he must be indestructible as a poet until he is destroyed as a human being."

What kept them going was that they were besotted with poetry and, despite themselves, with dreams of its possibilities. They stayed up all night reciting, arguing and declaiming, and then the next day they wrote impassioned letters of quarrel and encouragement to one another.

Poems still get written, naturally, but the flames, one suspects, don't burn quite so hot these days. Poets behave better, live longer and probably settle for less. If someone of Lowell-like talent and Lowell-like ambition were to come along now, it's not a given that poetry would be his or her No. 1 career choice. If you had a literary bent and really wanted to become famous and leave a stamp on your generation, you would write novels or screenplays. Or, better yet, you would set your verses to a bass line and become a rap artist.