The Letters of Robert Lowell ed Saskia Hamilton

Lowell and his contemporaries - Berryman, Bishop, Plath, Schwartz - have long been marked down as "confessional" poets, a label that disintegrates upon even the slightest analysis. All poetry is performative; this book, and other volumes of letters, have the virtue of showing us that the verse we have admired is not the poet's only means of objectifying and analysing experience.

Lowell knew most, if not all, of his poetic peers, and early in life he had set about cultivating the previous generation. After showing no particular intellectual distinction in youth, he decided in his teens to become a poet and began assiduously to acquire the necessary talents and connections. When he wrote to Allen Tate asking to come and stay for the summer at Tate's house in Tennessee, Tate tried to wriggle out of it by saying that the house was so full of poets that anyone else would have to sleep on the lawn. Up pitched Lowell with his "translucent green umbrella tent" and stayed on the lawn for a month. It was this persistence, not unmixed with outright flattery, that would later win him the friendship and tutelage of Pound, William Carlos Williams, Robert Frost and George Santayana.

Writing of his contemporaries, though - and usually to his contemporaries - Lowell was catty, entertaining and startlingly acute. The letters show us Randall Jarrell, with his "scrolled-up sphinx tone... emotionally immature, puritanical, monstrous, odd; but his peculiarity is part of his excellence." There is Dylan Thomas: "dumpy, absurd body, hair combed by a salad spoon, brown-button Welsh eyes always moving suspiciously or fixing on the most modest person in the room". There is Theodore Roethke: "a sort of tender hard-heartedness, too great a wish to be big, so that much of the poetry is a little dead under the ringing cadences." And then there is the gossip, clever people on clever people. Jarrell on Edith Sitwell: "a skull fattened for the slaughter". Pound on Cummings - "a razor-blade without the handle" - and Cummings on Pound: "You're humane without being human."

Many of the best letters in this book are written to Elizabeth Bishop, the only one of Lowell's contemporaries whom time has proved truly his poetic equal. Lowell cottoned on to Bishop's talent early, and she his, and watching their friendship deepen over nearly 30 years is one of the chief joys of this collection.

It was, for all its mutual kindness, a complex relationship. Lowell, who often developed by imitation of or reaction to poetry and people that he admired, found Bishop's poetry compelling and exciting because of its difference from his own: "You always make me feel that I have a rather obvious breezy, impersonal liking for the great and obvious," he writes to her, "in contrast with your adult personal feeling for the odd and genuine." Bishop, by contrast, admired and was occasionally envious of Lowell's productivity, but more than that of his sense of entitlement to a poetry that she herself had to fight for. Her comment to him in 1958, after seeing the poems that would become Life Studies, is a psychological biography in a paragraph:

"I am green with envy of your kind of assurance. I feel that I could write in as much detail about my Uncle Artie, say - but what would be the significance? Nothing at all. He became a drunkard, fought with his wife, and spent most of his time fishing - and was ignorant as sin... Whereas all you have to do is put down the names! And the fact that it seems significant, illustrative, American, etc, gives you, I think, the confidence you display about tackling any idea or theme, seriously, in both writing and conversation."

Bishop lived in Brazil for many years, and Lowell seems to have found it easy to apostrophise her there; his letters, though compendious and keen to incorporate all the gossip, also offer judgments on his own work that he never shares with those closer to him. Writing prose, he writes, "is a hell of a job - it starts naked, ends as fake velvet." Elsewhere he complains revealingly: "How easy it is for me to lay it on, and mean it." And he describes the aftermath of his destructive manic attacks to her in careful and unassuming detail: "One is left strangely dumb, and talking about the past is like a cat's trying to explain climbing down a ladder."

If Bishop was his best friend, she was not so without reservation. Lowell, when manic, would occasionally forget, or ignore, that Bishop was a lesbian, and after one peculiar visit early in their relationship she writes to a friend: "I do want to remain friends but I think it is going to require great care and fortitude and a rhinoceros skin into the bargain."

A rhinoceros skin is what many of Lowell's friends and intimates were forced to develop, and not all of them liked it or stayed the course. A plot, of sorts, is provided for this book by the irregular rhythms of the protagonist's manic depression, and one can usually spot, with a kind of bemused horror, an attack on its way. Lowell's tendency when manic was to take a new girl and begin mulling on the possibility of marriage; he dispatched breezy letters to his friends indicating a divorce from Elizabeth Hardwick, his long-suffering wife, and began to make plans for a new existence. The relapse into normality usually left him shattered and guilty, worried that the mania was a consequence of his own immorality and not just a mental inevitability. "It's been imbecilic, inhuman, dangerous, embarrassing and hell on Elizabeth," he writes after one attack. "I feel like a son of a bitch." When later in life he was prescribed lithium, rather than Thorazine and electroshock, his anger is palpable. Twenty years' psychotherapy and analysis, he wrote, might as well have been "for a broken leg".

Seeing Lowell like this is a potent antidote to the unkindness and arrogance that many critics found in the man and his work. His decision to adapt letters from Elizabeth Hardwick after the break-up of their marriage for his book Dolphin can probably never be justified as humane, but it is at least illuminating to see the correspondence around it with Hardwick and his friends. ("I feel like a man walking on two ever more widely splitting roads at once," he writes to Hardwick, "as if I were pulled apart and thinning into mist, or rather being torn apart and still preferring that state to making a decision.")

Without the need to perform in metre, Lowell's guilts and cavils are differently explored, made more comprehensible than when expressed as adjuncts of the poetic consciousness he cultivated. "I was naked without my line-ends," he writes at one stage in a phrase that Saskia Hamilton, the editor of this volume, appropriates for her excellent introduction. That nakedness, from such a guarded poet as Lowell has often appeared to be, is appealing and enlightening.

One feels, though, that Saskia Hamilton has been somewhat ill-used by her publishers. The notes are excellent but brief: Lowell's peripatetic existence and the breadth of his reference really demand lengthy commentary, and being able to keep track of his existence outside the letters (which girl is it now? is he in the bin?) helps too. And despite its title, this is not a complete edition; for reasons of space many letters have had to be excised. If Lowell wrote a string of letters from one place, that place will only be noted at the top of the first letter to save space, which sounds like a good idea in principle, but rapidly becomes infuriating. They could have cut down a few more trees and had a definitive edition.

Ian Hamilton's biography of Lowell, still the most influential document on the poet, was published five years after Lowell's death to howls of protest from the poet's intimates. Wisely, lethally, it placed Lowell's mania at the centre of the book, treating his sane periods as blessed aberrations and his excursions into poetry as mysterious acts of alchemy. Caroline Blackwood, to whom Lowell was married when he died, complained that it "did not show why people loved [him]". Saskia Hamilton (no relation) has produced a book of letters that goes at the very least a long way to remedying that.