Writing in 1821, with an assurance that seems barely credible in 1984, Shelley declared poets to be ''the unacknowledged legislators of the world.'' More than 100 years later, W. H. Auden took a much less sanguine and more modern view of the poet's status. ''Poetry,'' Auden said, ''makes nothing happen.''
The work of Seamus Heaney and Robert Lowell, in part because they have achieved such renown in a society that tends to relegate poets to out-of-the-way corners and in part because they have both tried, in different ways, to express what they see as the conscience of their countries, suggests some answers to the questions raised by the distance civilization has traveled from Shelley's view of the poet to Auden's: What is the importance of the poet to a world seemingly convinced that it can do quite well without him? What does the poet have to say about that world that is not already being said by the legions of sociologists, psychologists, and journalists undreamed of in Shelley's day? What, if anything, can poetry make happen?
Though from different backgrounds (Lowell was brought up in a prominent Boston family and Heaney in a rural area of what is now Northern Ireland) and different generations (Lowell was born in 1917, Heaney in 1939), these poets share a commitment not only to the tradition and worth of poetry, but also to the belief that the poet has a responsibility, however unacknowledged it may be, to engage the political and social realities of his time.
When the current round of violence in Northern Ireland began in 1969, Heaney was living in Belfast and had just published his second volume of poems, ''Door Into the Dark,'' a book that, like his first, was chiefly concerned with recapturing his rural County Derry experience. As he later acknowledged, 1969 changed all that. ''From that moment,'' he said in an essay, ''the problems of poetry moved from being simply a matter of achieving the satisfactory verbal icon to being a search for images and symbols adequate to our predicament.''
The most important of those images was already at hand, in the final poem of ''Door Into the Dark'', called ''Bogland'', that described the vast tracts of bog in Ireland, with their remarkable powers of preserving artifacts and bodies from remote civilizations, as a symbol for the Irish sensibility, turned inward upon itself and its many-layered history. In his next two volumes, ''Wintering Out'' (1972) and ''North'' (1975), Heaney found in the astounding archaeological discoveries made in these bogs a way of writing about the fanaticism and violence going on, often quite literally, in his backyard.
A poem entitled ''Punishment,'' from ''North,'' shows how Heaney uses the large historical perspective inspired by this archaeology to take his reader far beyond a sociological or political understanding of the Ulster troubles. After describing the exhumed body of a young woman hung centuries ago as an adulteress , the poem takes a characteristic leap to the present, to the practice in contemporary Ulster of tarring and feathering young Roman Catholic women seen going out with British soldiers:
My poor scapegoat,
I almost love you
but would have cast, I know,
the stones of silence.
I am the artful voyeur
of your brain's exposed
and darkened combs,
your muscles' webbing
and all your numbered bones:
I who have stood dumb
when your betraying sisters,
cauled in tar,
wept by the railings,
who would connive
in civilized outrage
yet understand the exact
and tribal, intimate revenge.
This poem does far more than deplore the mistreatment of Catholic women in Belfast or Londonderry. By insisting on what Heaney has called ''the archetypal pattern'' connecting a remote age with the present, it reveals fundamental qualities of human nature that are, it seems, timeless - not just the silent compliance and voyeuristic ambivalence that permit such atrocities, but also, as the last two lines suggest, the need of a community to punish violators when the community is defined in part by that very need.
In other bog poems, Heaney draws connections between the victims of ancient, pagan fertility rituals and those sacrificed to the infertile political and religious fanaticism that has so divided and diminished life in Northern Ireland today. As in ''Punishment,'' the comparison not only suggests the futility and meanness of the contemporary fighting, but also, by seeing it as part of a long human history of fanaticism and sacrifice, argues for what Heaney has called ''its deplorable authenticity and complexity.''
If Heaney's art has inevitably had to respond to the events that have shattered the surface of life in his native Ulster, the most important of Robert Lowell's poetry, published between the late 1950s and the late 1960s, was subtly but surely shaped by the far-reaching political and social changes that America experienced in moving from the darkly threatening years of the cold war to the openly disruptive years of the war in Vietnam. ''The world is very much under my skin,'' Lowell said in 1961, ''and really seems like a murderous nightmare when one looks outward.'' Lowell's poetry, however much it may focus on his private life, almost always looks outward as well, and his nightmare vision of the collapse of moral values and of the loss of individual freedom and possibility is ultimately a vision of life in contemporary America.
Vereen Bell's ''Robert Lowell: Nihilist as Hero'' (Cambridge: Harvard University Press, 251 pp., $17.50) makes a convincing argument that Lowell's poetry is ''identifiable by nothing so much as its chronic and eventually systematic pessimism.'' And yet, as Heaney pointed out in an essay on Lowell, that nihilistic vision did not lead Lowell, despite a life tortured by frequent mental breakdowns and suicidal impulses, down the path taken by some of his contemporaries, poets like John Berryman or Sylvia Plath. ''They swam powerfully into the dark swirls of the unconscious and the drift toward death,'' Heaney said, ''but Lowell resisted that, held fast to conscience and pushed deliberately toward self-mastery.''
It is this paradox - this almost overwhelming pessimism countered by a sustaining faith in his work - that makes Lowell's poetry speak so eloquently to the American experience, and that gives its readers a way of seeing that experience in terms of an overarching vision of the human condition in the 20th century.
Even in his early, often obscure poetry, Lowell's temporary faith in Catholicism is described as a moral center threatened by the amoral, self-centered hedonism that he later sees at the center of America's corruption (from ''Concord'': ''Crucifix,/ How can your whited, spindling arms transfix/ Mammon's unbridled industry?''). But it is in ''Life Studies,'' (1957) that Lowell's vision of a nation coming apart at the seams surfaces fully. The book's structure reflects the convergence of Lowell's private concerns with those of his country, moving outward from poems charting the moral and economic decline of Lowell's once-prosperous and powerful family (''My Last Afternoon with Uncle Devereux Winslow,'' ''Commander Lowell,'' ''Terminal Days at Beverly Farms'') to poems that track this loss of cohesion across the much broader territory of American life in general (from ''Waking in the Blue'': ''and see the shaky future grow familiar/in the pinched, indigenous faces/of these thoroughbred mental cases''; from ''Memories of West Street and Lepke'': ''where no agonizing reappraisal/jarred his concentration on the electric chair - /hanging like an oasis in the air/of lost connections'').
In the politicized and turbulent 1960s, Lowell's poetry carried this vision into more overtly public ground. ''For the Union Dead,'' (1964) links Lowell's loss of personal innocence with what he sees as the decay of America's moral center, eaten away by a corrupt and corrupting servitude to the god Mammon evoked earlier in ''Concord'': ''Everywhere,/ giant finned cars nose forward like fish;/ a savage servility/ slides by on grease.'' And if, as Lowell's biographer Ian Hamilton suggests (''Robert Lowell: A Biography,'' New York: Random House, 527 pp., paperback, $8.95), ''For the Union Dead'' reveals Lowell ''treating his own torments as metaphors of public, even global ills,'' the last stanza of what is probably Lowell's best-known public poem, ''Waking Early Sunday Morning,'' published in 1967, exemplifies his ability to see a specific event like the Vietnam war in the context of a much broader, more terrifying vision of nihilism:
Pity the planet, all joy gone
from this sweet volcanic cone;
peace to our children when they fall
in small war on the heels of small
war - until the end of time
to police the earth, a ghost
orbiting forever lost
in our monotonous sublime.
What rescues this poetry from the black hole toward which its vision seems to drive it so relentlessly is Lowell's extraordinary commitment to his art. The body of poetry that Lowell left behind him stands as a monument to the courage that kept him writing right up until his death in 1977 in the face of his own bleak view of the human condition, and of a personal life full of pain and disappointment.
This side of Lowell is especially evident in his later poems. In ''Fishnet,'' for example, published in his penultimate book in 1973, he takes a Yeatsian comfort in the edifice that he has constructed out of a life of public and personal despair:
The line must terminate.
Yet my heart rises, I know I've gladdened a lifetime
knotting, undoing a fishnet of tarred rope;
the net will hang on the wall when the fish are eaten,
nailed like illegible bronze on the futureless future.
That fishnet is also Lowell's legacy to the poets who have come after him, including, of course, Seamus Heaney. And in an elegy written at Lowell's death, Heaney pays tribute to Lowell in terms that recognize the value not just of Lowell's poetry, but of poetry in general - its ability to make something happen by taking us into waters that are treacherously uncharted but ultimately regenerating:
. . . You were our night ferry
thudding in a big sea,
the whole craft ringing
with an armourer's music
the course set wilfully across
the ungovernable and dangerous.