In 1993 the American poet Louise Glück was awarded a Pulitzer Prize for The Wild Iris. Last year she published a volume of essays, the testimony of a severe - severely truthful -practitioner, Proofs & Theories (Ecco Press, $22.00).

The introductory essay, 'Education of the Poet', cannot have been easy or pleasurable to write, anatomising as it does, without concealment or fudging, a poet's growth towards uncompromised and strictly inimitable work. One paragraph in particular may strike readers with the force of a truth unfashionable, inspiriting in a time of poetic laissez faire:

And if I had, as yet, no idea what kind of patience would be called for in my life, I had, by that time, already ample experience of what is called 'writer's block'. Though I hated the condition, a sense that the world had gone gray and flat and dull, I came to mistrust the premise behind the term. To be more precise: I can make sense of that premise in only two ways. It makes sense to presume fluency when the basis of the work is some intuition about language profound enough to be explored over a lifetime. Or when the work is anecdotal in nature. Even for the writer whose creative work arises out of the act of bearing witness - even for such a writer, a subject, a focus, must present itself, or be found. The artist who bears witness begins with a judgment, though it is moral, not aesthetic. But the artist whose gift is the sketch, the anecdote: that artist makes, as far as I can tell, no such judgment: nothing impedes the setting down of detail, because there is no investment in the idea of importance. When the aim of the work is spiritual insight, it seems absurd to expect fluency. A metaphor for such a work is the oracle, which needed to be fed questions. In practical terms, this means that the writer who means to outlive the useful rages and despairs of youth must somehow learn to endure the desert.

The desert, Louise Glück makes clear, is differently experienced by those writers (not many, perhaps) who experience it at all. She gives access to the glaring tracts of her own desert, in which words will fail her for years at a time.

The Proofs of her title are the provings, from her experience, in her work and reading: the testing out, the measuring and appraising of linguistic and moral value. She uses the word 'moral' unproblematically. One realises that when she uses the word 'true', or the word 'language', she knows without doubt what she means, and her attentive reader will understand her since what she writes is grounded again and again in lived particulars, but particulars which have been examined from every angle, so that the poet is as fully consdous as she can be of what she is doing. What she says may be a surprise, but never merely a surprise. Poetry is a form of discovery which avoids reflex and repetition, which makes the complex sense not of statement but of formal inference and resolution. 'And one of the revelations of art is the discovery of a tone or perspective at once wholly unexpected and wholly true to a set of materials,' she says in another essay. This truth to materials - to language, to occasion, to antecedent - is the most rigorous proof of a poem.

The Theories of the title are not those that find favour in modern seminar rooms but those that grow from observation and practice: not generalisations but testable plausibilities, true within contexts, and therefore scrupulously contextualised.

One of the most suggestive essays in her volume is 'Invitation and Exclusion'. Here, again tracing the course of her own reading (the one sure 'proof she has), she differentiates kinds of poetry. Her argument has to do with 'the other', with notions of 'voice', with transcendence and its failure, with soul, the terms scrupulously located and defined against actual poems. Prufrock's is clarified by sharp contrast with the voice of Stevens's 'The Idea of Order at Key West': Lady Lazarus is set in the balance with Emily Dickinson's very different intensities.

Great pain, in Plath, resurrects the violent ego which renounces comparison, being obsessed with boundaries. Dickinson manages to be both intensely personal and devoid of egotism: in a sense the poem is about being devoid of ego. But I want to stress a more technical point: the poem resolves in a search for precedent, or analogy.

It does Louise Glück scant justice to snatch fragments out of her integrated mediations. My intention is to recommend her essays, and her poems, the more recent volumes as yet unavailable in Britain. In its irony-shy clarity her criticism recalls the contemporary poet to certain priorities. Truth to materials, what a cold formulation! And yet it may draw some younger poets - those dissatisfied with the space the poem is expected to occupy today, with the poems that are endorsed by the media and award-giving bodies -back from audience applause to a severe solitude of judgment, making certain questions and answers unavoidable. 'Voice' here takes on a wholly different valency from the one it is generally given, and 'investment' recovers the force it had before bursaries, awards and the reading circuit became the command economy of Parnassus.

*

In July falls the centenary of Robert Graves's birth. What a perennially young poet he remains: it is possible to forget that he died nearly a decade ago. How neglected he is, too, in critical debate. In the bourse of reputations he's seldom quoted, as though for all his youth, his telling and retelling of the 'one story', he has become a poet of the remote past, timelessly young rather than our near contemporary. He is fixed - by his lyrical strategies, his strange theories (less strange than Yeats's), his unambiguous sexuality, his remove from the political fray, his memorability, his mere success - in marble stillness. He is an anthology presence while lesser poets of the generations he spanned, and to which he contributed, crowd the foreground. Bare acknowledgement is a form of neglect.

When as an apprentice poet Graves called on Thomas Hardy at Max Gate, the old poet confessed that he revised his poems very little, subjecting them to three or four drafts at most. Graves even at that time was a reviser par excellence, endlessly adjusting, altering, often years after a poem's first emergence in language. His hectic forming and reforming is Virgilian, moving always towards an elusive final statement.

Graves's characteristic rather than particularised voices have an archaic inflection. He depends on the power of word and rhythm, not self dramatisation or a rhetoric inherent in familiar imagery, to evoke experience. What his best poems say is inseparable from the words used; he is, 'the last pure lyric poet in English'. One is refreshed by his aloofness from the orthodoxies of the generations he lived through. He is old fashioned not like Housman, or Larkin, but like Jonson, Herrick, Rochester, speaking in despite of ephemeral decorums, fulfilling an older mission, a more earnest, delightful engagement with language.

The poems speak from the borders, not the past. The experience of World War I defined early Graves. War haunts the poems, though it did not shape him as it did David Jones. The memory of war is heavy with consequence but not, as for Blunden, binding him to the dead: it sets him apart from the living.

Has he no friend at court to intercede?
He wants none: exile's but another name
For an old habit of non-residence
In all but the recesses of his cloak.

The 'old habit of non-residence' was prompted by a love of the Mediterranean, a rejection of industry and its technologies, the desecration of native landscape, the impoverishment of relationships. Rather than stay and endure, or resist as Betjeman did, a decline, Graves retired, sending back messages of his and our progress, a retrospective radical, not a reactionary, speaking from an unregainable world.

Returning to civilian life after the war, the tension in his poetry changed: the craftsman drawn towards aestheticism became metaphysician, psychologist, wayward philosopher. He moved from innocence to different sorts of knowledge. Later he returned to innocence - the passionate, aroused old age of innocence intensified, not betrayed by experience.

Laura Riding ('the strong pulling of her bladed mind') left no area of his concerns untransformed. Their names were associated from 1926 to 1939. She gave him a vivid sense of technique as a servant of truth, an instrument of revelation. The poet was not a word-player, but a truth-teller, or he was nothing. A poem could not be made: it had to be discovered in the language. Michael Roberts summarised her beliefs in these terms: 'Poetry is the final residue of significance in language, freed from extrinsic decoration, superficial contemporaneity, and didactic bias.'

Formal experiment usually occurs well within the bounds of tradition. There is no startling innovation in his verse -indeed what startles is the authority with which he deploys the subject matter and imagery of romantic love poetry in the present age with authority - the effortless contemporaneity of the timeless, an unostentatious brilliance which would be as comprehensible to Gray as it is to the attentive Modern reader 'Love is the echoing mind, as in the mirror/We stare on our dazed trunks at the block kneeling.'

'He becomes dull, trusting his clear images:/I become sharp, mistrusting my broken images.' Trust is best invested in the senses: 'He in a new confusion of his understanding;/I in a new understanding of my confusion.' There is Socratic hubris here, yet the voice persuades us not by beguiling tone but by precision, even if that precision is as much a function of rhetoric as of philosophical clarity. This poem, celebrating the aleatoric, fragmentary, unpredictable, is (ironically) in a consistent, even a contrived, argumentative form. Formal deftness at times runs against his thematic and critical cavils - yet formal certainty is the only certainty he has. It orders uncertainties, clarifies areas of confusion. From the instability of feeling and the ephemeral epiphanies of the senses he wrests a fitful celebration of love.

Craft is exercised on the recalcitrant content of passion, and against the erosions of time. The poems illuminate coherent areas in chaos. Beyond each poem darkness forms again, or the poet comes up against a mirror and discovers he has been travelling in the wrong direction, into self. He declares:

… no soft 'if, no 'either-or',
Can keep my obdurate male mind
From loving true and flying blind.

A major poet? Has he the generic range to sustain the title? Time will tell? Time has told. We should look at Graves with the same intensity we confer on Stevens, on Auden and on Lowell.