You can go off people.

In last week’s TES, Gerard Kelly and Andrew Adonis enthusiastically berated the independent sector for our various failings: isolationism, mission drift, failure to live to up to the principles of our founders, over-concern for the interests of our own pupils, lack of charity. It was all there. Former schools minister Adonis even began with a reference to the “Berlin Wall” between the two sectors. We always know where we are going when that old chestnut crops up: straight to the land of fantasy and posturing.

Let’s try to get some balance and realism back into the debate. TES editor Kelly asks what we in the independent sector use our independence for, other than the benefit of our own (presumably unworthy) pupils. It is a perfectly fair question. Of course, I hope and believe that the pupils in our schools gain a great deal from their experience. Our independence allows that experience to be richer, more varied, more imaginative, more value-driven and more readily directed towards the needs of particular children than is often possible within a state monopoly. It is not because our schools or our leaders are better. It is simply because of the liberating quality of independence.

It is also palpably true that the initiative, strength of mind, ambition and sheer resilience of the independent sector has a significant impact - measurable in some cases - on the national education debate and on national education development and policy. Independent schools have pioneered the Extended Project Qualification at AS level. It was through the independent sector that the Pre-U qualification was born as an alternative to the A level. Independent schools began the serious and far-reaching experimentation with the International Baccalaureate. The brave and imaginative choice of some independents to abandon a 16-plus examination entirely in favour of their privately designed and carefully focused courses will, I think, be similarly influential. It was the resistance of independent schools to be driven by the fads and whims of educational thinking in the 1960s and 1970s that proved it possible to combine traditional rigour with genuine child-centred teaching and learning in a way that we now all seem to accept.

That is what independence is for. It ensures that a section of education is able to resist the blanket judgements, the sometimes ill-considered and occasionally downright stupid pronouncements of government and of the educational establishment. Independent schools are able, instead, to rely upon the vision, ambition and imagination of their leaders, governors and staff. Sometimes they reveal truths that the government and the establishment missed - not always, but sometimes.

Many of our colleagues in the maintained sector and many political observers understand this only too well. Ironically, Adonis was one of the most vocal and surely the most prominent. Much of the thinking behind the academies movement is based on precisely the arguments outlined above - the idea that the liberation of individual schools benefits all schools.

So why is Adonis bashing us now? He bemoans the great barrier that exists between the independent and maintained sectors. He blames it on us. He accuses us of isolationism and reminds us of our charitable duty.

We want to play a part

I realise that it is a pity to allow facts to get in the way of a good argument, but I think it is time. There is no “Berlin Wall” between the two sectors. There is no “isolationism”. It is absolute tosh. I have worked in the independent sector for more than 30 years. There is closer collaboration, greater shared working and greater trust between the two sectors - both locally and nationally - than ever before. And this goes way beyond the normal patronising references to shared playing fields. It involves full and partial partnerships, shared governance initiatives, summer schools, joint teacher training, collaborative work in shortage subjects, regular and highly valued meetings between leaders in the two sectors and much more. It is educational, not charitable - and that is a really important point.

If Adonis thinks that proper collaboration between state and independent schools will be founded upon charitable duty, he has completely missed the point. It will be founded upon educational drive, upon educational vision and upon a truly shared ambition for UK education to be among the best in the world. That is what we all want to be a part of, so please don’t patronise us by suggesting otherwise.

Banging the charity drum simply will not produce the results he wants. Firstly, a number of fine independent schools are not charities at all (interestingly, it does not limit their commitment to ambitious outreach and partnership programmes). Secondly, the stated charitable purposes of the others are nowhere near as precise as Adonis seems to think. Even where they are specific, the schools concerned are privately committed to exceeding their stated charitable targets through extensive programmes of fee assistance, bursaries, outreach and partnership activity. We do, and always will, fulfil our charitable duties. If, in addition, you want us to be more fully involved in national education, so do we. But please treat us as committed educationalists, not as naughty, over-privileged children who owe you something.

You may detect a note of frustration here. We in the independent sector have offered time and again to meet with government (and with Adonis, in my case) to discuss the opportunities for further integration and collaboration between the sectors. We see ourselves as a fully functioning part of the education system, not some kind of appendix to it. We want to be involved. At local level, we frequently are. At national level, ministers and members of the House of Lords cannot seem to find the time to talk (nor, apparently, to listen). Instead they make do with repetitive political posturing. It all gets a bit tiresome.

Kenneth Durham is headmaster of University College School in North London.