The truth is, we remember what we want to

THE NEWS that Stanley Baldwin probably didn't have a mistress does not come as a shock, but it is a little disappointing. For a brief, prurient moment, the story in Thursday's Telegraph ('House links Baldwin with mystery woman') held out hope. The sharp-eyed owner of a pleasant residence in Stow-on-the-

Wold had noticed that his title deeds bore the names of 'The Right Honourable Stanley Baldwin' and of a widow called Mrs Lucy Isaac, and showed that they had bought the house jointly in 1922 and retained it for 10 years.

Why should a leading politician be involved in such a set-up, except to provide a love-nest? Obviously, the stainless reputation of Britain's most phlegmatic and (until 1990) greyest Prime Minister, who contemptuously denounced press barons as harlots and sacked a king for wanting to marry a divorcee, was about to be besmirched. Unfortunately, the simple explanation did not long stand up to scrutiny. There was a swift expert dismissal. Professor Keith Middlemas, Baldwin's biographer, pooh-poohed the idea. Admittedly, Mrs Baldwin was 'a bit of an old bat', but Stanley 'simply wasn't that sort of man'. Then the Telegraph's own sleuths got to work: on Saturday, the paper declared the riddle solved. Baldwin was an old friend of Mrs Isaac's husband Arthur, killed on the Somme in 1916: in his will he appointed the politician as joint executor with his wife. Everything, in short, was above board, and explicable as a legal device.

A pity, but there it is. Should we, however, completely abandon such a promising historical possibility? Conceivably, Professor Middlemas and the Telegraph's detectives could have jumped too readily to the innocent conclusion. We still know little about Mrs Isaac. We do know, however, that Baldwin was a reserved and even secretive man, as well as a crafty one. If he was able to conceal such an unusual purchase from the world, not only at the time, but for the next 71 years, he was surely capable of other deceptions. Here we may speculate. The Conservative premier was well known for his indolent lifestyle, and for taking extended holidays in Aix-les-Bains: perhaps these trips were a front, designed - in the days before intrusive journalism - to hide illicit visits to Gloucestershire.

Although there is no evidence that Stanley and Lucy were lovers, there is no way of proving they were not. Indeed, it was Mrs Baldwin - was it not? - who advised her four daughters before their wedding nights to 'lie back and think of England': counsel that somehow lends credence to the mistress theory. We shall never know. Probably, there is no more to be said. However, when the name of Baldwin is mentioned at a saloon bar somewhere a decade or two hence, a savant is bound to say: 'Wasn't he the Prime Minister who had a bit on the side tucked away in the Cotswolds?'

Facts are curious. As the authors of 1066 and All That triumphantly showed, it is usually the wrong ones that people remember. Those that are right are recalled only in semi- apocryphal bits. A fact, according to the dictionary, is 'a thing that is known to be true'. But very few things are, and nearly all of the billion trillion events that take place every micro-second vanish completely, leaving no trace. We speak of 'recorded history' as though we have a comprehensive understanding of what has happened in the 5,000 years since the invention of writing, but we know virtually nothing. Even in this century only the tiniest particle of what happens is ever put on paper (or tape-recorded, or videoed) and what isn't thrown away is a particle of that.

Most records are designed to deceive. Have you ever read minutes of a meeting that state: 'Then the chairman threw a wobbly, and attacked his colleagues as ignorant fools'? What the minutes probably say is that the chairman 'suggested ways in which performance could be improved'. All official accounts put a gloss, including those of Cabinet meetings which (as Mr Heseltine once observed) can be the most imaginative of the lot.

Some records, however, are better than others. The most useful kind of evidence to the historian has been the methodically kept diary, written close to the events and not intended for publication. We are ignorant about Mrs Isaac because she did not keep one; by contrast, Frances Stevenson, Lloyd George's mistress, has a permanent and honoured place on Olympus because she did. Diaries offer intimacy, frankness, atmosphere. However, they are always biased. As readers of the published journals of the Harold Wilson era will be aware, when two or more diarists describe the same encounter, they almost invariably contradict one another. Political diaries are normally written for eventual publication, and so leave out the really sordid details. Occasionally the author leaves unintended clues - as in William Gladstone's massive journal, whose strange markings Professor Colin Matthews has been able to decode as evidence of unusual sexual practices.

In the days of Gladstone and Baldwin, people wrote letters that were long, intimate and revealing. Asquith used to scribble highly indiscreet billets doux to his girlfrend during Cabinet meetings. Now they use the telephone and so (buggings and answering machines apart) this kind of data is much reduced. One reason, however, why even the most illuminating diaries and letters give a distorted impression of the world in which they were composed, is that certain kinds of people wrote and hoarded them more than others. Biographies of the Bloomsbury Circle abound because its members chronicled each moment of their leisured lives, and then stored their outpourings. There are few working-class heroes whose lives remain as vivid: the reason is that they wrote little and what they did write ended up on a bonfire in some long-forgotten spring cleaning.

Nevertheless, the sources are not solely to blame for the gaps in our knowledge. The main reason why some things are 'known to be true' and others are not is that the public is choosy about what it wants to remember, and to find out. Galileo was executed for saying that the sun did not go round the earth: truths can stare you in the face, but they do not become things 'known to be true' unless people have the stomach to accept them. On the whole, society is hostile to information that upsets its view of the established order. It likes to be shocked, but not to be disturbed. People enjoy the details of the latest rape or murder, but they do not care to learn too much about the injuries inflicted by British and American planes on tens of thousands of conscripted human beings in the Gulf war. In the heyday of the British Empire people did not know about the suffering of subject races; Germans in the Third Reich did not know about the extermination of Jews in the camps; people used not to know that lesbianism existed, that child abuse was rife, or that smoking tobacco damaged your health, not because the evidence was unavailable but because for various reasons they preferred a state of ignorance.

They also liked to regard royalty and Cabinet ministers with awe, and to believe that they led blameless lives. Today, the opposite is the case, and the things known to be true have altered accordingly. Baldwin probably did not have a mistress. However, the significant fact - and the reason for the original press report - is that we would all have been delighted if he did.

Neal Ascherson is on holiday