Some alumni of grammar schools have always had suspicions about the failings of their alma maters. They certainly did well by at least a percentage of their pupils. The successes enjoyed the life, the work, the games and prestige and went happily on to university. But because they learned to count as well as read, they realised that something was wrong about the numbers.
The classic four-form entry municipal grammar school - far better resourced than the comprehensive or secondary modern down the road - enrolled 120 or so new recruits. They were said to be the cleverest 15 per cent of their age group. Usually they came from supportive families in which the parents read and talked to their children. They were taught by highly-qualified teachers in small classes and were encouraged by the special incentive that comes from being identified as a high flier. And what was the result? More often than not, three quarters of the pupils who entered at 11 left at 16. About 20 - from an intake five times that great - went on to university.
It is amazing that the shortcomings were tolerated for so long. Perhaps one of the impulsions behind the comprehensive revolution of the 1960s and 1970s was the knowledge that the old, complacent grammar schools could not meet the demands of the Robbins Principle and equip every student with suitable ability and adequate ambition to qualify for a higher education place. But until now, no one at the heart of education policy has dared to contradict the shibboleth.
Three cheers, then for David Normington, head of the schools directorate in the Department for Education and Employment, who gave the official imprimatur to what has been known, but never spoken of, for years. Addressing a meeting of Kent headteachers, he accused some grammar schools of "coasting" at a level of achievement just high enough "to keep them out of trouble with the DFEE".
Mr Normington's admirable honesty raises an immediate and crucial question. If the 166 remaining grammar schools are not squeezing every ounce of potential achievement out of their pupils, what is the point of keeping them?
They are supported and defended as centres of excellence which guarantee success for natural achievers. If they are coasting along in the warm glow of assumed superiority, how can anyone possibly defend their continual existence and the damage which they do to the schools around them?
Perhaps, after all, God was educated at a comprehensive school. Just as the Government begins to prepare for the parental ballots which can end selection, a senior official of the DFEE shoots down the major argument used in defence of keeping selective schools. The insistence that only vandals would want to destroy "good schools" was always misconceived. Now we discover it to be wrong. The good schools are not so good after all.
Not that the new acknowledgements about poor performance will end the battle to retain the selective school system. Grammar schools possess an attraction which dare not speak its name. Places at grammar schools are what economists call "possessional goods". Their acquisition offers status to the owners and all who are associated with them - whatever the intrinsic merits of their possession.
Having a son or daughter who has "passed the 11-plus" (or some equivalent examination) scores almost as many points as driving a Jaguar, owning a house in the country, or skiing in Austria at Christmas. It makes the lucky family feel superior to the comprehensive people next door.
The battle to retain the selective system is more about status than it is about education. That is one of the reasons why the selective system must be ended.