MICHAEL FOOT fought his first general election campaign 72 years ago. He is the supreme witness to the history of parliamentary democratic socialism in Britain, its triumphs and (more often) its travails. He has embodied the contradictions of a self-contradictory movement more completely, more often, than anyone.

The clichés are easy to summon. The shaggy-haired pensioner in his "donkey jacket" at the Cenotaph; the Aldermaston marcher; the truculent Bevanite; the party leader who defended "the longest suicide note in history"; the finger-jabbing stump speaker; the romantic parliamentarian; the Swiftian polemicist; the 18th century rhetorician in a 20th-century pullover; the perennial dissenter; the long-winded loser swept aside in the sound-bite age. All accurate, but not entirely true.

Appropriately for a bibliophile, Foot's tale, like Labour's, has bookends. Both, oddly - perhaps not so oddly - can be found to the right of history's shelf. First is Ramsay MacDonald's calculated defection from the party in 1931, to form a "national government" in alliance with the Tories.

Michael Mackintosh Foot was still a cradle West Country Liberal then, what Kenneth O Morgan describes as a "nonconformist patrician". He had yet to discover Stafford Cripps, the people of the Liverpool docklands, or socialism. He was a sickly product of a Quaker private school (much loved) and Wadham, Oxford (ditto). But the party he joined in 1935, aged 22, and represented in hopeless Monmouth during that year's election, was scarred by MacDonald's betrayal.

Seventy-two years later, an old man rumbles still over betrayal and illegal wars. Tony Blair, the other bookend, can fairly be seen as the agent of the extinction of Foot's chosen party. If history is an argument, Foot lost. The rightwards march of Labour, commenced by the despised Hugh Gaitskell half a century ago, has reached a terminus in the last, definitive betrayal. Between those limits lies a life.

Heroes have been Foot's affliction. He has indulged too many of them, too often, and more often than an educated person should countenance. Morgan's affectionate biography does not speculate as to reasons, but his subject's need to idealise favourites, and brook no criticism of them, suggests a psychological weakness. To put it brutally, as a reminder: this is not what socialists do.

Montaigne, Swift, Byron, Hazlitt, Disraeli, Wells: there you find the Foot style, and most of the habits of his mind. You find, mostly, a sometimes tedious romantic. You also find a distinctly non-socialist attitude common among the bookish, founded on a myth. Men such as Foot tend to believe that great, Promethean artists are necessarily great and moral men. There is no evidence for the superstition.

Here we have a Foot we can switch from Byron to Beaverbrook without a murmur. Here we have a Foot for whom Hazlitt and Hampstead mattered more, always, than Keir Hardie. Why did he take the counterfeit shilling of "Max", his lordship, and the Express group? Just for a career?

In Morgan's version of events, the answer is plain: merely because the shilling was offered, and merely because he "loved" Beaverbrook, his patron and surrogate parent. What would an actual socialist have said?

Lord Copper from Canada was a fascist in every meaningful sense. Foot was his comedy "beard" and there is no excuse, from that day to this, for Michael Foot, member of the National Union of Journalists, editor in name, running Beaverbrook's Evening Standard. Why forget?

People forget the point of ancient history. In Morgan's account we have an urbane Michael Foot discovering an "unusual" friendship with Enoch Powell over convivial 1970s dinners in suburban London. No "rivers of blood" over that table. They talked about books, instead, and deferred to a higher Oxbridge calling. Dishes mopped, Foot went back to denouncing Tories and the Tory returned to his calling: the - I can't do Powell - blecks.

We have Blair because we had Foot: the left contrived it. It's what they once used to call a historical fact. Foot made Blair both possible and necessary. Too much rubbish was spoken over nuclear bombs and dissent and the rights of parliamentary socialism. Foot, blethering - and even in his kindly account there is half a century of sheer blethering - allowed the alternative.

This sometimes sloppy, always deferential, and often recurring account of a long life makes no amends. Morgan admires his subject, and admires him tediously. Foot is excused at every turn, even when he chose to be a loyal minister of the crown. The job of journalism, never mind historians, is to make the call. Michael Foot? Hero? Man of letters?

Socialism harbours a strange prejudice. It asks, with no good reason, for proof of authenticity. It wants to know - and it really wants to know - who you are, really. Nye Bevan, the least-deserving of Foot's many heroes, once judged his protégé as always a Liberal, at heart, and the child, always, of the old West Country Liberal, Isaac Foot.

Morgan's terrible portrait merely affirms every judgement. There is no reason to admire Michael Foot. There is no reason, equally, to admire any of those patrician socialists, of any stripe. It's what used to be known as a contradiction.

Foot is old, but no wiser, I think. Why was he a candidate 72 years ago? Just because socialism defers, as it still defers, to bookish Oxbridge types. Call me old-fashioned in the age of the Tony, but wasn't that, once upon a time, the opposite of the point?