Biography: The reader over my shoulder, as I began this biography, was its reticent subject: the Orcadian poet, essayist and fiction writer, George Mackay Brown (1921-1996).
A deeply self-conscious man with a passion for privacy, a reverence for anonymity and a wariness of the least intrusion into his life, he proved a distinctly queasy autobiographer in For the Islands I Sing, the short, shy memoir he left for posthumous publication.
I could easily imagine his lantern jaw clenching and the gas-flame blue of his eyes intensifying as he checked out the pages of Maggie Fergusson's biography, with which he was prepared to co-operate "so long as nothing was published in his lifetime".
Why, unless he harboured some shameful secret, was Mackay Brown so squeamish about his biography and autobiography? Other than his widely-known devotion to John Barleycorn, were there skeletons clinking like whiskey bottles in his cupboard? Not one, it turns out - unless you count a susceptibility to depression, inherited from his father; an inhibition or suspicion about committing himself to long-term amorous relationships; a self-censoring tendency, as an older writer, because of "a striving for personal purity . . . that sometimes bordered on neurosis". Fergusson's disclosures hardly amount to revelations. In an accusatory age, when every biographer feels entitled to look down gleefully from a dunghill height at his or her subject floundering on feet of clay, she has produced a refreshingly perceptive, empathetic and even affectionate book.
If Mackay Brown has been unusually fortunate in attracting a biographer who is both a stylish writer and a sympathetic recorder, Fergusson herself has not been presented with an easy task. Non-marrier, non-driver, non-traveller, non- performer of his work in public, her subject might seem a non-starter for a full-length biography. Unlike his fictional characters, he never ran away to sea or trysted with the laird's daughter; and was content to live as far from literary centres as Stromness (his small coastal town) is from San Francisco and to remain about as fashionable as a bere bannock in the age of blueberry bagels.
Although the best-known of the triple-named poets (whose number include Sydney Goodsir Smith, Ian Hamilton Finlay and Iain Crichton Smith) who were his contemporaries, he was always underrated; his one brief brush with fame came in 1994 when his novel, Beside the Ocean of Time, was short-listed for the Booker Prize.
The most beguiling of storytellers, without being the most nimble engineer of the novel form, Mackay Brown was unquestionably a writer deserving of attention. But, living alone in his little council flat, he was driven to distraction and depression ("the prize was causing George such distress that he was taking antidepressants") by the media frenzy.
Whether shaping his local newspaper columns or his novels, short stories and poems, Mackay Brown was prolific and professional. A devoted writer by vocation and a devout Catholic by conversion, he remained a Calvinist by work ethic; and he exorcised prying and prattling summer tourists by pinning on his front door - like an article of faith - a three-word proclamation: "Working all day". After many years of being nursed for tuberculosis or self-nursing his morning-after hangovers, he had gradually acquired this regular work habit, which earned him enough to meet his meagre needs. He was proud to eke out a living from his royalties and he indignantly refused to live more royally on a Civil List pension.
Always reluctant to leave Orkney, Mackay Brown intensified his imaginative vision by narrowing his geographical horizon. Apart from his fleeting one-off visits to Ireland and England, he never strayed farther than the Scottish mainland. His happiest time in mainland exile, his "golden age", occurred when, in 1951 and 1952, he was part of a highly congenial class at Newbattle Abbey near Edinburgh, an easygoing adult education college in a stately home (wooded surroundings, wood-panelled rooms, five Van Dyck portraits). Fortuitously, the warden at Newbattle was the inspirational and supportive Orkney-born poet, Edwin Muir, whose autobiography, The Story and the Fable (1940), Mackay Brown revered.
Later, Mackay Brown became a keen student of Edinburgh's literary pubs - Milne's in particular - during his undergraduate years at the university there (he would take a degree in English literature in 1960); and soon the thin, duffel-coated man with the laboured breathing and the hollow cheeks proved surprisingly adept at holding his own among the lits and wits of the city. It was in Milne's that the 36-year old poet met Stella Cartwright, ardent and exuberant at 20, with whom he fell in love. But their romance was, as it were, the Milne's without the boon; their engagement was broken off and - though they remained friends to a greater or lesser extent until her death at 47 - her early decline into drunkenness, destitution and Zimmer-framed infirmity makes for painful reading.
There were revitalising relationships with two other young women; but Mackay Brown's well-settled ways did not seriously allow for the prospect of a muse becoming a spouse. When pondering possible reasons (vocational, psychological and spiritual) for this reluctance to marry, Fergusson treads delicately; and she mercifully spares us speculative sessions on the Freudian couch. Not exactly a Shelley, Byron or Marlowe where the eventfulness of his life is concerned, Mackay Brown is nonetheless compellingly and vividly portrayed in this book, even when the biographical excitements rationed to the reader relate to nothing more momentous than the poet's first-ever dance at the age of 66 or his first bottle of shampoo at the same age (until then, it was to Fairy Liquid that he owed his luxuriant hair).
Just as Edwin Muir discerned the larger fable within every life story, Mackay Brown traced the archetypal patterns underlying everyday lives and the sacramental core secreted in the most humble human routines. His poems were often structured around rudimentary cycles: the seasons, the days of the week, the months of the year or the Stations of the Cross. Sometimes, his words filled these forms mechanically, like ready-made moulds; at their brilliant best, though, the poems are flooded with the light of revelation and illumination like the Neolithic tomb at Maes Howe - the Newgrange of Orkney - on a crisp mid-winter day.
While he may seem over-eager to escape to the heraldic world of the Orkneyinga Saga and the lamplit hearths of childhood crofts, his rooted, conservationist vision speaks urgently to our own deracinated, globalised, consumerist age. His island has much to teach ours, not least regarding our destructive assumptions about "economic growth": "The notion of progress is a cancer that makes an elemental community look better, and induces a false euphoria, while it drains the life out of it remorselessly."
• Dennis O'Driscoll received the 2006 O'Shaughnessy Award for Poetry from the Center for Irish Studies in Minnesota. His Bloodaxe Book of Poetry Quotations will be published later this year.
George Mackay Brown: The Life By Maggie Fergusson John Murray, 363 pp. £25