The theory that lay behind the post-war establishment of grammar, technical and modern schools was that children could be distinguished according to aptitude and ability, and that it was proper to provide them with different education and experiences. Many special schools, mostly run by charities, already shared this general philosophy and aimed to provide education from which, for example, the deaf, the physically disabled or epileptic could benefit.

These schools now increasingly fell under the local education authorities (though many retained their charitable status); but some children were left out. They were deemed incapable of benefiting from any education and were the responsibility not of the local education authorities but of the health or social services. Parents of such children were not obliged to send them to school, indeed there were no maintained schools to which they could be sent.

Then, in 1970, legislation was passed to bring all children, however severe their disabilities, under the aegis of the Department of Education. No child might any longer languish at home or in a long-stay hospital deprived of education altogether.

A committee of inquiry was set up by the then Education Secretary, Margaret Thatcher. The committee, which I chaired, reported in 1978 and its recommendations were incorporated in the 1981 Education Act. This enshrined for the first time the concept of special educational needs. It is easy to see it now as the last gasp of welfarism: provision should be determined by need, virtually regardless of cost.

The 1981 Act was morally motivated; like the welfare legislation of the Attlee government, it treated education as an intrinsic good. More importantly, it widened the scope of the concept of special education by concentrating not on particular things wrong with children, but on what they must have to gain access, as far as possible, to the whole educational experience. Education was thought of as a shared path down which all children must walk, though for some it was a smooth and easy road, for others fraught with obstacles, to be removed one by one.

At the time, about 2 per cent of schoolchildren were being educated in special schools. The committee of inquiry discovered that far more children than this - at least 20 per cent of those in school - would at some time or another experience a special need, even if only temporarily. Special needs therefore became normal. There was a continuum of needs. The children in question were not hidden away; most of them were in ordinary schools and, given the new optimism about the help they could be given, it was plain that many others in special schools could be moved into mainstream education.

However, my own view was, and is, that there is still a place for special schools, as centres of expertise. They are also a necessary part of the education of some children, such as those who used to be called “maladjusted” and the very severely multiply disabled.

There were two problems. First, what was proposed in the Act could not be afforded. Second, the committee had recommended that the most severely disabled children should be issued with official “statements” setting out their needs, the local authority having a statutory obligation to meet them. This was supposed to be a way of prioritising certain needs as well as ensuring that if a child moved from one authority to another the obligation would pass on. The committee intended that only about 2 per cent of schoolchildren would have statements.

The “statement” has been a disastrous mistake. As money for education lessened so it became clear that little would be done to meet the needs of a child unless he or she had a statement and so parents increasingly demanded that their child be “statemented”. This meant increasing delays before anything would be done for the child and, worse, local authorities began to list the child’s needs to match what they could afford, not the true needs. The appeals system also involves expensive and time-consuming litigation.

Worst of all, those children without statements yet with identifiable educational needs which could be met successfully are liable to be simply overlooked, which puts us back almost to where we were before the 1981 Act. The widened scope has narrowed again.

This may be too gloomy a view, though I do not think so. In any case, looking back on the days of the committee, when everyone felt that a new world was opening for disadvantaged children, the most strikingly absurd fact is that the committee was forbidden to count social deprivation as in any way contributing to educational needs. And the distinction is actually incorporated in the 1981 Act.

The very idea of such a separation now seems preposterous. Of course there are many intellectually, psychologically and physically disabled children who are not socially deprived. But the vast majority of children with special needs are as they are, at least in part, because of their social, and especially their linguistic, deprivation. Perhaps it is time to rethink the whole concept of special needs.

Baroness Warnock was chairman of the Committee of Inquiry into Special Education from 1974-1978