It's a puzzle how Gordon Brown manages to maintain the aura of a serious intellectual. He clearly reads widely. But so, too, do my nephews, albeit books with shorter words. The problem lies not with his ability to read but to draw the correct conclusions.

His speech yesterday on social mobility is a case in point - a weird mix of platitudes and outright nonsense. Parents should want their children to do better than they did themselves. Wow. What an insight. And this “cannot be achieved without people themselves adopting the work ethic, the learning ethic and aiming high... We must set a national priority to aggressively and relentlessly develop the potential of the British people.” It's difficult to imagine a priority aggressively and relentlessly to hold back the potential of the British people.

The difficulties start when he talks in more than platitudes. Yesterday's speech was predicated on the notion that, while he had been fortunate to be “a child of the first great wave of postwar social mobility”, there was then a “lost generation” of “Thatcher's children” who were denied the chance to progress. Mr Brown is right to talk about the reversal in social mobility that took place in the last century. But he is about as far from the truth as it is possible to imagine in describing its cause. Margaret Thatcher did not create the problem; she inherited it.

A 1996 study by the Institute for Fiscal Studies confirmed what strikes most people instinctively: education is the great engine of social mobility. “There is a clear correlation between high mobility up the income distribution and a high level of educational attainment. Non-movers are almost five times as likely to have no qualifications as big movers; at the other end of the scale, big movers are more than seven times as likely to have A levels or better than non-movers are.” And with the educational opportunities laid out in Rab Butler's 1944 Education Act, which enshrined the tripartite system of grammar, technical and secondary modern schools, increasingly it was no longer true that where you were born on the social scale determined where you ended up.

Times Archive, 1965: Government clarifies plan for education switch

It is made clear in the long-awaited circular that all selective secondary schools should eventually disappear

• Leading article: Second best

As Churchill said to the boys of his alma mater, Harrow School, in 1940: “When this war is won... it must be one of our aims to establish a state of society when the advantages and privileges which have hitherto been enjoyed by the few shall be more widely shared by the many, and by the youth of the nation as a whole.”

And this started to happen: the proportion of public-school-educated undergraduates at Oxford was, for instance, on a steady downward path after the Second World War. In 1946 65 per cent of male students were from independent schools. By 1967 only 53 per cent of male students were from public schools. The pattern was even clearer with women, the share falling from 57 per cent of arts undergraduates in 1946 to 39 per cent in 1967. For all the problems with technical and secondary modern schools, grammar schools did a fine job of lifting children out of poverty and into opportunity. Yet today, our comprehensive system has one of the worst rankings in the developed world.

Education was seen by the advocates of comprehensive schools “as a serious alternative to nationalisation in promoting a more just and efficient society” (as Tony Crosland, who would not rest until he had “destroyed every f***ing grammar school”, put it). But this was Grade A drivel. Class divisions were made worse, not better. Now those who can afford to do so leave the state system for private education or move to a middle-class catchment area. The rest are stuck with what they are served up. As A.H.Halsey, an adviser to Crosland and one of the leading egalitarian theorists of the 1960s, put it: “The essential fact of 20th-century educational history is that egalitarian policies have failed.”

The speed of the process was astonishing. In the late 1960s the state grammar schools and quasi-state direct grant schools easily outclassed the independent sector in terms of academic output. The next decade saw both these meritocratic pillars of the state school system collapse. In 1971 35 per cent of all state schools were comprehensive; in 1981 the figure was 90 per cent, and almost all the direct grant schools had joined the private sector. In destroying the direct grant schools on the altar of equal opportunity, the 1974-79 Labour Government succeeded only in denying opportunity to many poor children.

Mr Brown is right to emphasise the imperative of social mobility. But until he stops speaking in platitudes and starts understanding what has gone wrong, he will never be able to put anything right.

Stephen Pollard is author of A Class Act: the Myth of Britain's Classless Society

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