BOOK REVIEW / The philosophy of philandering: Bertrand Russell - Caroline Moorehead: Sinclair-Stevenson, pounds 20

BERTRAND RUSSELL may well have been the greatest philosopher of the 20th century. At all events, he bequeathed to philosophers in the English-speaking world not only the problems with which they still wrestle, but the analytical techniques they bring to bear on them. When Russell was in his early thirties, his collaborator on Principia Mathematica said he thought Russell had the acutest philosophical intelligence since Aristotle. But of course Russell was much more: a passionate campaigner against wars and the governments that waged them; a journalist of genius who knew just how to irritate, inform and amuse a lay audience with his views on sex, vegetarianism, movie-going or the vice of smoking cheap cigars; a formidable philanderer; and a friend who could startle with unpredictable kindness or equally unpredictable callousness.

He was born into aristocratic liberalism in the most literal way. His grandfather, Lord John Russell, introduced the Reform Bill of 1832 and started Britain on her way to democracy. His father, Viscount Amberley, wrecked his parliamentary career by arguing in favour of birth control as well as votes for women. The confidence this aristocratic background gave him lasted all Russell's life; in the First World War he thought nothing of addressing himself to President Wilson, and in the 1950s he thought as little of addressing himself to Nikita Khrushchev and John Foster Dulles on behalf of nuclear disarmament.

One could hardly ask for a more tempting subject for biography - nor, given the complexity of his ideas, for a more difficult one. Caroline Moorehead has not done at all badly. Wisely, she steers clear of the more vertiginous cliffs and chasms of Russell's analysis of mind and matter, thought and logic. What we get is essentially figures in a landscape - Bertie among the Apostles, Bertie and Ottoline, Bertie and the pacifists of the First World War.

Given that Russell was born in 1872 and died nearly 98 years later, and that in the course of this long life he moved between Cambridge, London, the USA, China and Russia, between academic life, political activism, high journalism and low, schoolmastering and the conduct of a love life of astonishing complexity, it is no mean feat to paint his richly coloured social and intellectual landscape in the detail Caroline Moorehead does. Because Russell was so prone to fall out with his friends, both for personal and political reasons, he is oddly absent from the memoirs of people with whom he was at various points extremely close. To put him back in the houses and gardens he frequented for much of his life has taken a lot of unobtrusively handled reading and interviewing. But the plausibility of the result perhaps owes even more to the way Caroline Moorehead preserves an emotional calm that many readers find hard to hang on to when they get close to Russell.

It is not merely that he was politically unstable, lurching from passivity to insurrectionism as outside events provoked him. His character can easily seem repulsive. On his own admission, he was a frightful prig when young and an unprincipled philanderer in middle age. One can't read the letters in which he admits to one lover that he is betraying her with another without feeling that the combination of deception and self-deception would be discreditable in anyone, and particularly in the philosopher who declared that the disinterested search for truth was one of the great glories of human civilisation and the courage to live unflinchingly in the face of unpleasant truths one of the greatest of moral virtues.

Caroline Moorehead doesn't flinch. She records the fact that most of Bloomsbury detested Russell's bleakness and emotional austerity, and deplored his commitment to politics rather than private happiness; she chronicles the hatred that the saintly G E Moore and Ludwig Wittgenstein came to feel for him; she acknowledges that his relations with the pacifists with whom he worked in the First World War often rested on bad faith - they wanted to bear moral witness to the evils of war, while he wanted to use them as a mass movement to stop the war. But she resolutely doesn't take sides: she surveys the scene with the benign sympathy that never came naturally to her cast of high-grade egoists.

It is a matter of taste whether the price the reader pays for this good-natured approach is too high. If you think - I do - that from first to last what makes Russell interesting is the dazzling intellect, the clarity of thought and the fearlessness with which he tackled every issue he encountered, you will wish there was less Garsington and more about Russell's analysis of Marxism or nuclear disarmament or pragmatism or the reduction of mathematics to logic. If you feel you can turn elsewhere for that - most of Russell's voluminous output is still in print - and want to know what it must have been like to live alongside that extraordinary personality, this is as persuasive a picture as you're likely to see until all the papers of Russell's friends and family are opened sometime in the next century.