Andrew Adonis, the Schools Minister, did not even try to hide his irritation. Writing in The Times on August 21, the day the GCSE results were released, he lashed out at those who would claim that the exams were being dumbed down instead of celebrating the increasing numbers of students getting A and A* grades.

"It is the class-based elitism that instinctively wants to ration success and cap the aspirations of the less advantaged," he wrote. "The underlying premise is that there is a fixed pool of talent in society." And then came this breathtaking assertion: "There is no genetic or moral reason why the whole of society should not succeed to the degree that the children of the professional classes do today, virtually all getting five or more good GCSEs and staying on in education beyond 16."

Why breathtaking? Isn't that pretty much what both Labour and Tory politicians say? It is part of the received wisdom among politicians whenever they talk about education: except for a few children with severe handicaps, they assert, all children can succeed on the academic track if the schools do their job. Politicians argue only about which policies will achieve this obviously attainable result.

Adonis's statement was breathtaking nonetheless because, scientifically, it is not true. His belief that nearly all children can be proficient at academic skills is educational romanticism. Many children are just not gifted enough to learn to read and write at more than a rudimentary level, far short of the level required by a GCSE, and the schools can only tweak their performance at the margins. An educational system that serves all the children must begin by recognising that truth.