His reputation may new somewhat battered but, for generations, Scott of the Antarctic was an inspiration, an example of courage and leadership. Now, our greatest living explorer is trying to make him a national hero again. Nick Morrison reports.

SIR Ranulph Fiennes is on a mission. Not, this time, to the North or South Poles, both of which he has reached, nor to find a lost city in the desert, uncovered 13 years ago, nor yet to run seven marathons in seven days, accomplished last year. This time, it is to bring Captain Scott in from the cold.

Scott is one of the most prominent victims of the revision of history and debunking of heroes of recent times. For half a century and more he was an inspirational figure, who narrowly missed being the first man to the South Pole and died on the return journey, but his tactics and leadership have been held up to the harsh light of modern thinking and found wanting.

He was a rigid disciplinarian who maintained the divisions between officers and men even under the harshest of conditions; he was reckless in exposing his men to danger; he showed poor judgement, including making the mistake of taking horses on his fateful last expedition instead of dogs; he practically even forced Titus Oates to commit suicide - all these accusations and more have been levelled at Scott.

But Sir Ranulph is leading the fightback. His new biography of Scott, published in paperback next week, aims to restore the reputation of a man who, he feels, has been unfairly maligned. And Sir Ranulph has one distinct advantage over the revisionists who have done so much damage to Scott's heroic status - he has been there.

Sir Ranulph knows what it's like to haul 200lb sleds at temperatures of minus 50. His Transglobe expedition, from 1979 to 1982, saw him, along with Charlie Burton, become the first person to reach both North and South Poles overland. In 1993, along with Mike Stroud, he completed the longest unsupported polar journey across the Antarctic, covering 1,345 miles in 95 days, an expedition finally abandoned when he developed crotch rot, frostbite and piles.

He also holds the record for the furthest journey North unsupported, in 1990, although his attempts to reach the North Pole unaided have ended in failure. The latest, a solo trek in February 2000, was called off after just a week when he developed severe frostbite in his left hand. He had to saw off his frostbitten fingertips with a fretsaw. It took about two days for each finger, a little longer for the thumb.

His exploits saw him named by the Guinness Book of Records as "The World's Greatest Living Explorer", and among his many awards are the Polar Medal, with clasp, and the Explorers' Club of New York Medal. If anybody knows the privations suffered by Scott and his team, it is him.

But he insists his expeditions did not make him sympathetic to Scott, instead they gave him an insight into why Scott took the decisions he did. "My experience didn't give me an empathy with Scott, it gave me an understanding of his problems," he says.

He was moved to write about Scott following an encounter with Raisa Gorbachev, former First Lady of the Soviet Union, in Moscow in the mid-1980s.

"She was telling me that Stalin worshipped Scott and Scott was a hero in the Soviet Union, but she had seen a film which showed Scott as a complete twit," he says. Intrigued, he saw the film for himself, as well as reading books on Scott's 1912 expedition, including one by the chief debunker, Roland Huntford, and started to question their conclusions.

"My memories of having seen the film and read the book were entirely unrelated to the reality of my experience in Antarctica," he says. "I saw the film and it seemed to me that he was a very flawed person, but everything in the film didn't gel. They get away with it because it is a subject which very few people know about and know they are talking rubbish."

Sir Ranulph, something of a hero himself, deplores the trend for besmirching reputations, but says with Scott the debunkers have excelled themselves. "We have done it time and time again, but seldom have we done it so far away from the truth," he says.

He cites specific slurs, such as on Scott's "pathetic" attempt to salvage something from the failure to be the first to the Pole by bringing back 35lbs of fossils, even though they weighed down his sledge. These fossils, Sir Ranulph says, subsequently proved that Antarctica was a continent and were evidence of the scientific bent of Scott's expedition, in contrast with the pure glory-seeking of rival Roald Amundsen.

Criticised for abandoning his skis and then having to go back and collect them, Scott was simply responding to the changes in the snow, which at one stage made it seem madness to drag around 25lbs of skis. The use of ponies looks less foolish considering that Amundsen had as many problems with his dogs, and the accusation that Scott was hated by his men is undermined by more evidence than supports it.

All of these charges are scrupulously tackled by Sir Ranulph, along with one which has the potential to be most wounding: that Scott glared at the frostbitten and weakened Titus Oates until the young officer left the tent and abandoned himself to the elements with the words: "I am just going outside and may be some time."

But the accusation that Oates was pressured into suicide is mere conjecture, unsupported by any account, although Sir Ranulph says Scott would have been aware that to prevent Oates from dying would have been to torture the remaining members of the expedition, Dr Edward Wilson and Lieutenant Henry Bowers.

He recognises that Scott made mistakes - in an environment where no one had ever been before it was inevitable - but says they were no greater than those by Amundsen and Sir Earnest Shackleton.

"If they were human they would make mistakes, but Scott made a lot fewer than Amundsen and Shackleton," he says.

He says Scott's death, along with those of Oates, Bowers and Wilson, far from being caused by Scott's foolhardiness, was a result of extreme weather conditions. "Given any average conditions, those four men would have made it back to their base with comparative ease," he says.

"As a scientist, Scott was unbeaten. The results which he and his men produced are well in excess of the total results of all the international expeditions during the first half of the 20th century.

"I don't like words like hero, but I would say he was extremely level-headed, very accomplished, very good at making judgements. The mistakes he made were minuscule for the onerous task he had been given in an utterly unknown region."

As for Sir Ranulph himself, now 60, he had been planning to retire, but earlier this year Ginny, his wife of 35 years and herself a recipient of the Polar Medal and the first female member of the Antarctic Society, died from cancer.

Now, he is turning his thoughts to conquering Everest next year, after he was contacted by a South African friend who was planning to scale the North route and wanted Sir Ranulph to accompany him. "I have not climbed anything before, but lots of people have climbed Everest," he says, seemingly not at all in awe of the challenge.

For overcoming obstacles and responding to challenges is what Sir Ranulph does. There is no sense of romantic notions, of the "because it's there" brigade. Rather, it is his job, to get sponsorship and to go on expeditions. "I make a living through doing this sort of thing. If I stopped doing it, I would stop making a living," he says.

It may be just a job, and he may not like the word, but it's that sort of thing that makes Sir Ranulph a hero, perhaps just like Scott should be.

Captain Scott by Ranulph Fiennes (Coronet £7.99)