The introduction of the national curriculum in 1988 was surely one of the few genuinely revolutionary changes in education of the past 50 years.

Every revolution needs a slogan, however, and if he were honest, what the then education secretary Kenneth Baker should have shouted as he stormed the school gates was, “galite, fraternite, bureaucratie!”

Two out of three isn’t bad, but the lack of liberte has hampered the national curriculum ever since. With more freedom, the curriculum would not only work much better, but it would at last provide a coherent philosophical framework for compulsory education.

The fact that the curriculum is too restrictive has at least been acknowledged by all the key players in education, including the three main political parties. In this paper last week, Education Secretary Ruth Kelly talked of her desire for a “creative curriculum” and “flexibility”, and the Government’s primary strategy has already provided some release from the prescriptive constraints of the old literacy and numeracy programmes.

In the same issue of The TES, Liberal Democrat shadow education secretary Phil Willis reiterated his party’s commitment to replace the national curriculum with a “minimum curriculum entitlement”. And the Conservative manifesto states the party’s intention to “slim down” the national curriculum.

But is greater freedom just the latest bandwagon, or is it underpinned by sound educational and philosophical principles? It may be self-evident that the current curriculum is too restrictive, but the case still needs to be made for why greater freedom is good in itself.

To make this argument, we need to consider why we have a national curriculum at all, and what its strengths and weaknesses are.

The official aims of the curriculum are to establish an entitlement and standards, and to promote continuity, coherence and public understanding.

In two other words, it’s all about egalite and fraternite.

But the pursuit of these laudable goals has had unintended consequences.

First, equality is achieved by standardisation and constant measurement.

This stifles two of the most vital parts of the education process: the enthusiasm and professionalism of teachers, and the development of curious young minds into mature ones capable of thinking things through for themselves. The stress on standards leads to the rise of the bog-standard, which is never a source of inspiration.

Second, a prescriptive curriculum also fosters the illusion that there is a fixed and finite canon of knowledge that we should and could all master.

The more exciting truth is that, beyond a few core skills in reading and writing, there are innumerable things it is worthwhile to learn about.

There is a world of knowledge to be explored, and a rigid curriculum which provides just one fixed route through it narrows the horizons of the learner.

Third, the constant stream of tests and measures presents an image of education as little more than a series of hoops we have to jump through.

School becomes less like an adventure playground and more like an obstacle course, when ideally it should combine the best features of both.

With greater freedom, the national curriculum can make a much better statement about what education is all about. With fewer compulsory components, a more convincing case can be made that these really are things everyone ought to know. Leaving greater space beyond that shows there are endless things that reward close study, all of which are worthwhile and can be pursued according to our own interests. It also gives teachers the chance to be at their best, because when lessons are about an instructor’s own passions, they are always more compelling.

Likewise, students will be more motivated if we give them more freedom to choose subjects that move them. If that sometimes means projects on less academic subjects, such as the history of hip hop, then so be it. After all, some academics get three-year research grants to do exactly the same.

Freedom is not just about lifting restraints but enabling people to use their own minds to the best of their abilities. While the curriculum remains a straitjacket, children’s brains are taught only to be responsive to the immediate demands of others. To set people’s minds free, schools need to enable independent thought. To do that, they need to be environments in which individual passions and interests are being pursued as a matter of course, and not just in a few extra-curricular corners.

We must find a place for liberte in the guiding ideals and practice of the national curriculum, because those who have not learned to think for themselves have not really learned to think at all.

Julian Baggini is editor of The Philosophers’ Magazine