A History of the American People by Paul Johnson Weidenfeld & Nicolson, pounds 25
Two spirits, alas! dwelled in the breast of Goethe's Faust, and two spirits, alas! dwell in Paul Johnson's. There is the tub-thumping bully of the Daily Mail, laying all the world's complex evils at the doors of a hideously caricatured tribe called liberals. And there is the stylish popular historian, author of an admirable History of the Jews and of other books, disfigured, indeed, by occasional ideological perversities like his odd preference for Warren Harding over Franklin Roosevelt, but still well worth reading. Which of these two unkindred spirits has now written the history of the American people? The answer is: both.

The first 750 pages of this book are by Jekyll Johnson, the graceful, fair historian. I particularly enjoyed his neat biographical sketches, of Alexander Hamilton, for example, or of Thomas Jefferson ("a fastidious devotee of all life's luxuries, from claret to concubinage"). Johnson is just as good on Henry Clay, who is portrayed unforgettably in Kentucky giving "a grand Terpsichorean performance ... executing a pas seul on the table, smashing $120 worth of china and glass"; while in Washington "he adopted a different accent, watched his grammar (not always successfully) ... and generally did his gentleman act".

Only occasionally does Hyde Johnson grab the pencil and manage to scribble in some ponderous neo-conservative anachronism, such as calling plans for repatriating slaves to Africa "a liberal solution" or comparing the Salem witch trials to Watergate. From first to last, Johnson promotes the idea of American exceptionalism. "The creation of the United States," says his first sentence, "is the greatest of all human adventures." "Looking back on its past and forward to its future," says his last, "the auguries are that it will not disappoint an expectant humanity."

That is the book's strength. For 750 pages it is written with a wonder and affectionate curiosity that sweep the reader along. Johnson has mastered a huge amount of material, yet made his narrative immensely readable. Professional historians will no doubt find fault with his interpretations. There is some force, too, in the criticism that this is not, as modern historians would see it, a history of the American people, so much as an old-fashioned general history of the kind that has been out of fashion for two generations. So much the worse for them. This is the kind of book that brings new readers to its subject by its freshness, its enthusiasm and the quality of its writing.

Almost to the end, Johnson maintains his detachment. His portraits of Woodrow Wilson and Harry Truman are as lively as his Andrew Jackson or his Abraham Lincoln. His set-pieces on the jazz age and on McCarthyism are as fresh as his account of slavery or the Great Awakening of American Protestantism. Even his portraits of Kennedy and Johnson, though sharp, are judicious. And then we come to Nixon, and Watergate.

At this point, Johnson leaves the rails. Or rather his locomotive jumps the points and careers off on new rails, leading straight for a gaping mineshaft of ideology and prejudice. He speaks of "hysteria", of "juvenilia". He says that the Plumbers were "engaged in a variety of activities of an entirely justifiable nature". That is not what the courts found.

He describes Watergate as a "media putsch". That is exactly what it was not. The President of the United States resigned to avoid virtually certain conviction on articles of impeachment. He was not brought low by the media, but because the whole system, from the police court to the Supreme Court, worked as it was supposed to do.

After Nixon, Johnson spirals out of control. He rages incoherently about "political correctness", not understanding that it was never anything but a slogan used by conservatives to dish the liberals. His account of the Iran Contra affair is a travesty. His account of the civil rights movement is trivial and inaccurate. He recites right-wing tittle-tattle about Clinton.

At one point, he actually leaves terra firma. After the new immigration began in the late 1960s, Johnson says, "America became in danger of embracing a caste system" or of setting up "the juridical infrastructure of a racist state, like Hitler's Germany".

Nothing like that happened. Nothing like that could happen in America. To use such wild language would be inappropriate in a tabloid newspaper. To use it in a history book, like the 13th stroke of a clock, casts doubt on all that preceded it. And it raises the question whether the United States Johnson knows, and claims to love, bears any relation to the real country beyond the walls of neo-conservative think tanks.