It is now 45 years since Michael Young launched his famous attack on the dangers of meritocracy. His thought-experiment The Rise of the Meritocracy warned of a future of social division based on intelligence.
Yet in truth Britain's problem 45 years on is not that we have too much mobility, marked by social vertigo of those on the rise and depression of those on the slide. Our problem remains that birth rather than worth still counts for too much, not too little. This is true in education.
All the independent evidence shows overall standards to be rising. But the bad news is that when it comes to the link between educational achievement and social class, we are in the relegation zone of industrialised countries. Today, three quarters of young people born into the top social classes get five or more good GCSEs, but the figure for those born at the bottom is less than one-third. We have one of the highest university entry rates in the developed world, but also one of the highest drop-out rates at 16.
Four factors are key to this depressing pattern. First, the simple fact of growing up in poverty, with the restrictions it places on housing, diet, lifestyle. Second, family factors - critically parental interest and support, which itself is driven by parental experience of education. Third, neighbourhood factors. The fourth is the quality of schooling.
The first three require long-term change in social and economic life. But the great power of schooling is that it is in our power to change it now, and change it for the better.