Robert Louis Stevenson by Claire Harman

Adventures of a literary buccaneer

HARPERCOLLINS £25 (503pp). £22.50 (free p&p) from 0870 079 8897

In the Edinburgh house where Robert Louis Stevenson grew up - 17 Heriot Row - stands a two-foot high statue of the writer in his Hawaiian period. Jacket off one shoulder, knickerbockers tucked into boots, RLS could almost be a leathery frontiersman. But the statue's hollow, haunted face belongs to a less sturdy man.

Stevenson was a literary buccaneer who travelled on the romantic edge. News of his sudden death in 1894 came as a shock. Henry James could not believe it; Rudyard Kipling was so devastated he was unable to write for a month. A cerebral haemorrhage had killed RLS at 44.

Half a century on, Stevenson's importance as a writer remains an issue. Is Treasure Island a fabulous allegory, or merely the trimmings of an old costume-chest? Should Kidnapped be viewed as just a superior Boy's Own adventure? And what of RLS himself, this consumptive Edinburgher in his velveteen smoking jacket? The photographs suggest a man who struck poses. If Stevenson and his work ever suggested a winsome sweetness, part of the blame must lie with the high Tory art critic Sir Sidney Colvin. In 1899, he published Stevenson's letters in such an expurgated edition that RLS emerged a rather bloodless creature.

Fortunately, the eight-volume edition of Stevenson's correspondence published by Yale in 1994-95 set the record straight. The editor, Ernest Mayhew, laboured heroically to remedy Colvin's errors and suppressions. For 25 years he lived with Stevenson's near-illegible handwriting; dredged archives and badgered American collectors. After Mayhew, it was no longer possible to banish RLS to the literary bagatelle. The letters bristle with slang ("boghouse", "blue fits") and saucy vulgarisms ("fuckstress"). A wayward creature, RLS was in rebellion against the family trade of lighthouse engineering.

Claire Harman's is the first biography of Stevenson to make use of the complete Yale correspondence. Yet, astonishingly, it adds very little to recent lives of Stevenson by Frank McLynn, Ian Bell and Brian Bevan, or indeed to personal appreciations by Nicholas Rankin ( Dead Man's Chest) and Hunter Davies ( In Search of RLS).

Nevertheless, this is a smoothly-assembled and readable study, which confirms Stevenson as a writer of the first importance. A dark apprehension lay beneath much of what he wrote, and The Strange Case of Dr Jekyll and Mr Hyde touches an elemental fear. The terrible scene where Hyde tramples over a child's body still evokes pity and horror. Whatever its detractors might say, the novella is a work of high philosophical intent.

Enchantment is one of the special qualities a writer must have, and RLS is always a delight to read. Stevenson's charm lies partly in his exuberant youthfulness, says Harman. As a boy RLS would "go Crusoing" in the lowlands of East Lothian, creeping about at night with a lantern. It was a short step from here to the tense action across loch and moor, the thrilling flight through heather that Henry James admired in Kidnapped, and which influenced Buchan's The Thirty Nine Steps.

Often ill as a child, Stevenson was pampered. His Calvinist nurse provided lullabies and cups of sugared tea but also, importantly, tales of sin and redemption in the Free Church. For all his quarrels with the Calvinism of his upbringing, Stevenson was at heart a religious moralist. Nurse Alison's stern morality may have influenced his great short story "Thrawn Janet", which broods on the evil in the world and in man.

Admitted to the Scottish Bar in 1875, Stevenson made some effort to practise as an advocate, but wig and gown were not his style. His struggle to become a writer brought new friends, among them Edmund Gosse. His marriage in 1880 to Fanny Osbourne, a quick-tempered American, was not altogether happy; according to Harman, Fanny was a jealous woman who kept RLS on a short rein.

Though well-researched, this biography shows signs of hasty work. Yet Harman's literary judgement is sound, and she rightly praises Stevenson's last, unfinished work, Weir of Hermiston. This is a novel that reconciles all the strands: adventure story, fable, Presbyterian morality. RLS was no longer the dandy in thrall to Baudelaire and symbolism. With Weir the old velvet-coated prose had disintegrated and, as Stevenson's distant cousin Graham Greene observed, "the granite was coming painfully through".

Ian Thomson's biography of Primo Levi is published by Vintage

Buy any book reviewed on this site at www.independentbooksdirect.co.uk - postage and packing are free in the UK