THE HALF-LIGHT of a Nashville nursing home is not gentle with Allen Tate. It drains the last color out of his fragile face and thinning hair, and turns milky the clear plastic tube from the oxygen tank.

At 78, Tate has only peripheral vision left; what he can see clearly is the narrow passage of his own life. "I am not what I wanted to be," he says slowly, "but I am not displeased."

Allen Tate, the man who articulated modernism for the modernist writers and who defined Southernism for the Southern literary renaissance, is like a great actor reciting Shakespeare in an empty theater. Once widely considered one of the major men of letters in the United States - and still revered by other writers, many of whom have written the Nobel Committee urging that Tate be awarded the prize in literature - he is now virtually unknown to the general public, slotted away by universities into surveys of Southern lit. He is often described as a "seminal figure," but his influence has been very specifically on other writers. In a real sense, he is the peot's poet.

This specialized success is ultimately a disappointment for the man Robert Penn Warren calls "one of the most important characters in American literature," but it is only one of the ironies that have wreathed themselves around Tate the literary kingmaker.

He was probably the most precocious intellect among the Fugitive writers at Vanderbilt, but it was Warren who won the Pulitzer prizes. Tate was consumed by his work far more than his fellow Americans in Paris, Fitzgerald and Hemingway, but their reputations have far outstripped his. As a college student, Robert Lowell left Harvard to camp out worshipfully in a pup tent for several weeks in Tate's yard - but Lowell had his Pulitzer fewer than 10 years later.

Tate was something of a classical scholar (graduating magna cum laude in Greek and philosophy) whose poetry is dense with classical forms and allusions; yet his private life was hectic and exhilarating. He was an enthusiastic drinker and chain smoker for many years, an entertaining party wit and something of a ladies' man. At the same time he could be very conservative, and his forecful first wife of three) was careful to restrict her language in his presence.

He is not a man to understimate himself or to be humble in the face of honors. But the celebration of his 75th birthday, which drew such guests as Eudora Welty, Richard Howard and Howard Nemerov to Sewance, Tenn., interested him only through the dinner session - be missed the readings of critical papers.

As poet, critic and either of the Sewance Review. Tate embodied the European ideal of the literate, cosmopolitan man: yet it was Tate who articulated the history/mythology on which the Southern renaissance was founded. Born Nov. 19, 1899, he was rooted as strongly by his life in the 20th. In 1937 - he declared. "The literary center of the United States is definitely in the South;" and 40 years later, he still clings to the ghost of the Glorious Defeat.

"If the South had won, we'd have been Yankified - industrialized - that much sooner," he said in a bedside interview, pushing away an untouched lunch tray. "The North didn't want the South back, they just wanted to exploit it."

And he still feels a proprietary interest in prominent Southerners.

"President Carter - you can tell he's a gentleman for many generations. His accent is Southern, but not ridiculous."

The man who by 30 had already published his best-known work. "Ode to the Confederate Dead," arrived at Vanderbilt in 1917 as a brittle, acutely self-conscious student determined to establish himself as an intellect. He prided himself on his literacy, while his study partner looked up Greek words one at a time in the dictionary. Tate concocted elegant phrases for their translations (some of which still exist). Inevitably, he ran head-long into the brick wall of a conservative English faculty. One teacher attempted to crush Tate by sarcastically inquiring."Do you know who Dante was?" Infuriated, Tate snapped back, "Do you know who Jesus Christ was?" The incident paradoxically won Tate many friends. Dean Herbert Tolman, who told Tate to apologize, added, "But Allen - you don't have to mean it!"

Tolman was one of many impressed by Tate. "As a young man, as a college student, Allen single-handedly invented for himself what you would call the modern poetic style, before he'd ever read Eliot or Crane," remembers Warren, who roomed with Tate at Vanddebilt. By the time he left Vanderbilt and The Fugitive, the literary magazine he'd helped found, for New York, Tate felt assured of a brilliant career.

He and his new wife, novelist Caroline Gordon, lived off his free-lance criticism, liberally laced with the slightly malicious wit his friends relisbed, in a cold-water third-floor walk-up in Greenwich Village. By 1928, he had worked his way up to a Guggenhein Fellowship, and subletting Ford Madox Ford's flat, he and Gordon embarked upon the literary life in Paris.

Actually, they found much of the expatriate society frivolous, and Tate, who was working on two biographies (of Jefferson Davis and Stonewall Jackson) and two volumes of poetry, considered himself too busy for much of it. Gertrude Stein, who expected him at her salon every Thursday, called him "Tate"; he invariably addressed her as "Miss Stein." He liked Fitzgerald better than Hemingway, but spent more time with Hemingway, driving out every Sunday to the bicycle races. "We were pretty friendly," he says, "but I think if I'd been writing prose, he wouldn't have had me around."

When they returned to the United States in 1930, Tate fell into the circuit-preacher style of academic lecturing by which most writers survive. He spent a few years at Southwestern in Memphis and a few more at the University of North Carolina. By 1939 he was head of the creative writing program at Princeton, where William Meredith, now poetry consultant at the Library of Congress, was an undergraduate.

"It was the authority of his criticism rather than any perceptions (that made Tate respected)," says Meredith. "He understood what criticism coming from 'a man of letters' in the European sense could mean."

Back in Tennessee in the early '40s, the Tates established themselves in a "country house" in Clarksville. There they hosted elegant dinner parties followed by intricate charades. During the day, Tate often went trout fishing, the one aberation of man who preferred to watch his friends exercise than exert himself. "Mr. Tate ain't much of a man behind the hoe, is he?" the yard man once remarked to Carolina Gordon.

In 1943 he was named to the chair of poetry at the Library of Congress. For Tate, whose mother's family was from the Washington area and who graduated from Georgetown Prep, it was a kind of homecoming. But it was far from a quiet, scholarly existence - it became a kind of Paris-in-D.C.

The four of them - the Tates, novelist Brainard Cheney (then working for Sen. Tom Stewart) and Frances Neel Cheney (former president of the American Library Association) - took an old house across the Anacostia River. It was promptly christened The Birdcage, "for a nest of singing birds," Meredith jokes.

"It was an elaborately done-up house - almost gaudy but with everything slightly undersized," recalls Cheney. "Katherine Anne Porter was living in the basement, Meredith was on the sleeping porch, and John Peale Bishop was in the extra room until we moved him across the street." There were lengthy visits from other literary friends like Lowell and his wife Jean Stafford.

In his 40s, and at the height of his reputation, Tate was a man who was fashionable without being foppish. He is invariably remembered as a man of exquisite manners, impeccable dress - he bought many of his suits in Europe and replaced his tuxedos as styles changed - and intense personal composture. He played the violin, not well but with pleasure, and greatly enjoyed concerts. Yet he was almost oblivious to furniture and food, with the notable exception of his addiction to ice cream. he smoked incessantly, but never affected a cigarette case. He was an avid "hail-fellow-well-met" partier, but equally prone to evenings at home spent in energetic discussion.

"Caroline is the most entertaining conversationalist I've ever known," says Cheney. "She has a kind of extravagance about her that heightens everything she says."

The Tates' was a marriage of two very different personalities drawn together by talent and mutual admiration. It lasted over 30 years altogether (they were divorced, remarried and divorced) before succumbling at last to the wear and tear of two creative energies.

"They had a profound, psychic, spiritual relationship," Cheney says. "She believed in him as an artist, and as a man she sustained him; and she drew a lot of strength from him. She had the highest respect for Allen's intellect and it was reciprocated. (But) she had violent enthusiasms and violent rages. She had a kind of monomania about Allen."

In 1959 Tate married the statuesque Isabella Stewart Gardner, poet and scion of the Boston Gardner Museum Gardners. That marriage failed fairly quickly, and in 1966 he married his present wife, Helen Heinz.

About 10 years ago, what Warren used to call Tate's Luck began to change. He developed the first signs of the emphysema that plagues him now. Helen had twins, but at 11 months one of the infant boys choked to death before a panicked babysitter. And a series of rifts appeared between Tate and his former intimates, quarrels usually attributed to Tate.

"Allen has a sharp tongue as well as a sharp wit," says Cheney. "It's a least a legend that he has fallen out with all his friends at one time or another, but" - dryly - "some of them have overlooked it." Another associate thinks it's a reflection of Tate's disappointment in his shrinking influence, a last competitiveness. The two who have most adamantly refused to quarrel with Tate are Warren and Peter Taylor.

Last year Cheney and two others orchestrated a letter-writing campaign to get Tate the Nobel Prize. It's one honor he would dearly love; typically, all he has remarked is that the money would come in handy.

"He'll never win for the same reasons in a mirror that Steinbeck did win - there is nothing in his work that could appeal to European Marxists," Meredith thinks. But one way or another, recognition will come: "With any permanent look into 20th-century American poetry, the company he kept and the respect he had from that company, his stock will go up, unquestionably."

To win a Nobel Prize, or even a Pulitzer, a writer must have a wide appeal.Tate will never be a "popular" writer, although a few of his poems, such as "Ode to the Confederate Dead," will continue to be anthologized. He was always the man to stand alone; to some extent, coalescing in his mind the commitment of the literary career, he deliberately remained aloof.

"The poet stands apart from society," he says as a member of an order. "As a poet he does not function in society . . . except as an observer." But his poetry truth made up of little fictions, must be a weapon against the advance of technology, rationalism, dispassion.

"'Our calculations have outrun our conceptions' - that's Shelley. This is a world of abstractions . . . we must constantly struggle to be free. A poem is a statement about something the intellect can't entirely deal with. It defines as problem, not the solution.

The tide of recognition has begun to turn again. In the past two years, Tate has won five literary awards, most recently the Lenore Marshall Poetry Prize from Saturday Review for his "Collected Poems, 1919-1976." But by now, the cash has greater value than the honor; bedridden with emphysema and nearly blinded by deteriorating retinas, Tate is harassed by medical bills.

His nursing home half-room, separated from the shuffles and smells of the hallway by a plastic curtain, has become his receiving room. A parade of visitors - professors and undergrads, fledging poets and old friends - are fitted around the Vanderbilt football games he follows on the radio. Sometimes they come, like the Cheneys, to gossip in the manner of long-time intimates; some read to him out loud from the new biography of T.S. Eliot. Often nowadays, they come to interview him, to remind him of his shadowy existence in this dim decade. But he eludes them, these too-early eulogizers: baffles them by his distant charm. he has allowed few people to know him during his life, and he will not change now.

"Tate is a man of severe and elitist judgements," says Meredith, the member of the next generation. "As society becomes more populist, his criticism appears less useful, and I think in fact is less useful - but it is not less admirable for that.

"I think the way to express it is that he's a Hamiltonian, and that doesn't get you anywhere these days."

"Ode to the Confederate Dead," first published in 1927 and revised several times before the final version appeared in 1937, is Tate's best-known poem, and the one which for many years he considered his best. A long-standing legend - sometimes taught in poetry classes at Vanderbilt - places the cemetery in Franklin, Tenn.; however, Tate says he based the visual descriptions on the Confederate cemetery in Richmond, which he saw as a child.

Row after row with strict impunity

The heasstones yield their names to the element,

The wind whirrs without recollection;

In the riven troughs the splayed leaves

Pile up, of nature the casual sacrament

To the seasonal eternity of death;

Then driven by the fierce scrutiny

Of heaven to their election in the vast breath,

They sought the rumour of mortality.

Autumn is desolution in the plot

Of a thousand acres where these memories grow

From the inexthoustible bodies that are not

Dead, but feed the grass row after rich row.

Think of the autumns that have come and gone! -

Ambitious November with the humors of the year,

With a particular zeal for every slab,

Staining the uncomfortable angels that rot

On the slabs, a wing chipped here, an arm there:

The brute curiousity of an angel's stars

Turns you, like them, to stone,

Transforms the heaving air

Till plunged to a heavier world below

You shift your sea-space blindly

Heaving, turning like the blind crab.

-from "Ode to the Confederate Dead"

"Last Days of Alice" is Tate's strongest enunciation of his rejection of a world filled with abstractions. It recalls also a quote he attributes to T.S. Eliot: "It is better to commit a sin than to do nothing."

Alice grown lazy, mammoth but not fat,

Declines upon her lost and twilight age;

Above in the dozing leaves the grinning cat

Quivers forever with his abstract rags:

Whatever light swayed on the parilous gate

Forever sways, nor will the arching grass,

Caught when the world clattered, undulate

In the deep suspension of the looking-glass

Bright Alice! always powdering to glaze

The spoiled cruelty she had meant to say

Grazes learnedly down her airy nose

At nothing, nothing thinking all the day.

Turned absent-minded by infinity

She cannot move unless her double move,

The All-Alice of the world's eutity

Smashed in the anger of her hopeless love,

Love for herself who, as an earthly train,

Pouled to join her two in a sweet one;

No more the second lips to kiss in vain

The first she broke, plumged through the glass alone -

Alone to the weight of impassivity,

Incest of spirit, theorem of desire,

Without will as chalky cliffs by the sea,

Empty as the bodiless flesh of fire:

All space, that heaven is a dayless night,

A nightless day driven by perfect lust

For vacancy, in which her bored eye-sight

Stares at the drowry cubes of human dust.

-We too back to the world shall never pass

Through the shattered door, a dumb shade-harried crowd

Being all infinite, function depth and mass

Without figure, a mathematical shrowd

Huried at the air - blessed without sin!

O God of our flesh, return us to Your wrath,

Let us be evil could we enter in

Your grace, and falter on the stony path!

-"Last Days of Alice"