BOOK REVIEW / The smelting nation: 'The Disuniting of America' - Arthur M Schlesinger: Norton, 10.95 pounds

'YOU cannot spill a drop of American blood,' said the novelist Herman Melville, 'without spilling the blood of the whole world.' And the essayist Ralph Waldo Emerson once said that 'Irish, Germans, Swedes, Poles & Cossacks, and all the European tribes, the Africans and the Polynesians will construct a new race . . . as vigorous as the new Europe which came out of the smelting pot of the Dark Ages.'

For a great part of this century, the American creed taught that immigrants of all nations and all cultures would be assimilated and converted by American institutions including, not least, American schools and colleges, into 'the American, that new man'.

There have always been those who resisted the 'smelting pot'. Early in the 19th century, nativists resented German and Irish immigration; and Know-Nothings resisted Catholics. By the Twenties, after the great surge of immigration between 1890 and 1917, a campaign against immigration resulted in the Immigration Act of 1924, which froze immigration into quotas based on the national origins of the population in 1890.

But the shared misery of the Depression, the ideology of the New Deal and the ideals of the Second World War (which was, if not a war against racism, then at least a war against racists) reinforced the appeal of the melting- pot. The Kennedy administration abolished the 1924 quotas, thus opening the door to the New Immigration from Asia and Latin America which has, in the past 25 years, replaced the dwindling trickle of European migrants.

Every action, however, in society as in physics, tends to have an equal and opposite reaction, and the civil rights revolution of the Sixties, itself a projection of the creed of assimilation, produced a new reaction against what the writer Michael Novak referred to as 'the unmeltable ethnics'. Blacks, too, either seeking to 'raise the consciousness' of their own people or to acquire political clout, turned away from integration and assimilation.

The consequence is a whole cluster of anti-assimilationist trends, cults and fashions in contemporary America. This deeply troubles Professor Arthur Schlesinger, one of the unbending champions of traditional, or New Deal, liberalism since the heyday of Americans for Democratic Action in the Fifties.

Now, in a small but forceful and learned tract, he has restated the classic liberalism of his youth. He has good reason to feel the need to do so: his book adds to the anthology of horror stories about 'political correctness' which have seeped across the Atlantic in the past few years. Here again is the New York State task force on minorities, led by the nose by its consultant, Dr Leonard Jeffries, who in his teaching at City College in New York contrasts the 'ice people' of Europe with the warm, sharing 'sun people' of Africa. Here, too, is the educational psychologist, Asa Hilliard, teaching young New Yorkers that Egypt was a black African country, that Africans brought science and philosophy to Greece and that such dead white males as Ludwig van Beethoven and Robert Browning were really dead black Africans.

Hilliard's essays have been adopted by public schools or taken as the basis for 'Afro-centric curricula' in more than a dozen American cities, including the capital. Students in New York State are taught that the 'Haudenosaunee political system' - the Iroquois Indian confederation - was an equal influence on the framing of the US Constitution with the colonial experience of government and the tradition of the European Enlightenment.

Schlesinger, it goes without saying, does not agree with this historical judgement. Nor is he in sympathy with the Office of Students' Affairs at Smith College, a famous women's school in Massachusetts, which enjoins its pupils to avoid 'ableism', defined as 'the oppression of the differently abled by the temporarily able'.

His point is not simply that much political correctness is ridiculous and pernicious, however. He refuses to be panicked by such silly instances of the politicisation of the curriculum, alarming though they are: he makes the point that most eminent black scholars find it even more offensive and ridiculous than their white colleagues do.

The motto of the United States, Schlesinger says, in that dead white language, Latin, is e pluribus unum: out of many, one. He restates that American ideal against the unmeltable ethnics, against the politically correct, the nationalists and separatists and cultural pluralists, and against those in politics who kowtow to them. He convincingly debunks, incidentally, the theory that there will soon be a 'minority majority' in America. But perhaps he underestimates the sheer pain that drives people in a society so relentlessly given to ethnic stereotyping to say: 'OK, you say I'm not a real American like you. So be it.'