John Bald is a former Ofsted inspector and has written two books on the history of writing and spelling. He is a Vice-Chairman of the Conservative Education Society.

Episode three of BBC2’s Secrets of Your Life Revealed contains an astonishing video clip, showing how a specialised brain cell detects active neural networks, wraps its tiny, tentacle-like dendrites around them and deposits a layer of myelin, speeding up the transfer of information along the network by 100 times. The cells are selective, reinforcing only the most active networks (shown in green on the video) and not touching the others (shown in red).

This combination of science and technology shows beyond speculation exactly what goes on in the brain as we learn, and it should transform the educational debate. Traditional teachers and modern Conservatives know from experience that closely-focused teaching, followed by practice, builds knowledge, and the understanding and skills that depend on knowledge. Our progressive opponents believe that learning is incidental to whatever is going on in the classroom, and place little or no value on knowledge and what most of us would see as teaching.

Their errors are all around us, whether in approaches to maths that expect children to solve problems without giving them the means to do so, “language-experience” techniques in English that expect reading and writing to be picked up without knowledge of the structures of the language, or “immersion” and “exposure” methods in teaching languages that leave pupils in a state of confused frustration. It is small wonder that the proponents of these errors have withdrawn from debate with us and are taking no notice of the brain research – they know they are wrong, and do not much care, as they are more concerned with moulding society than with the real process of teaching and learning. Research evidence that shows benefits from approaches to teaching that don’t fit their view – and there is now plenty of it – is ignored, marginalised and sneered at.

Constructing an alternative to the progressive view of education has been a long and difficult task. Early pioneers, notably Sir Rhodes Boyson, were subject to isolation and ridicule, partly because of esoteric views that ran alongside their good ideas on teaching. Later attempts had their own errors, notably Lord Baker’s first National Curriculum, which divided everything into ten levels whether or not this was appropriate, and then tried to sustain them with verbal gymnastics that destroyed their credibility. Professor Harvey Goldstein had a field day, likening the government’s use of the national curriculum to a drunk’s use of a lamppost, “for support rather than illumination.”

The first real breakthrough came with Sir Michael Wilshaw’s Mossbourne Academy, which backed its use of ability grouping and strict discipline with examination results that were so much better than local competition as to defy belief. In its first GCSE results, the top sets for Spanish and German achieved 28 and 24 A*s respectively, and the success was carried through into the sixth form. There was no arguing with good GCSE pass rates running at over 80 per cent, while the worst I’d seen in progressive Essex were as low as five per cent. Mossbourne had an immediate impact on attitudes in neighbouring schools – some were hostile, but others started to compete, and standards rose. I’ve seen the same effect in the one Harris academy in which I’ve worked.

Reliable evidence of improved standards is the key to winning the argument, and will not be fully in place until the examination reforms are complete. Nevertheless, the recent report The Question of Knowledge, produced by the Association of School and College Leaders, is an important development, as it puts the debate on a professional rather than political basis.

The knowledge-rich curriculum has never been the preserve of the centre-right – its most prominent protagonist, ED Hirsch, comes from the Left – but progressives have latched on to Labour since the sixties, and are delighted with Corbyn. I will declare an interest, having worked with the contributor, Ian Bauckham, Executive Head of Bennett Memorial Diocesan School, on the Teaching Schools Council’s report on language teaching, but his is one of only a few of these essays that backs up his arguments with hard evidence of progress from pupils. Many of the others contain statements of belief with which most Conservatives will agree, but this is not enough to settle the issue.

The root of the matter is succinctly expressed in Professor Geoff Whitty’s BERA address of 2005, in which he defends the right of professors to pursue their own goals and values, irrespective of politicians, citing a polite tiff with Labour’s Charles Clarke. For Professor Whitty and his colleagues, the goal is equality. For Conservatives, it is to enable each person to achieve the best of which he or she is capable. Building intellectual capacity through the knowledge-rich curriculum is consistent with what we now know about the operation and development of the brain. The progressive alternative is not, and has done great damage to those it most wanted to help. It must not be allowed to prevail.