There's one thing – just one – that most right-thinking educationalists seem to agree on: we need a new schools’ curriculum, one fit for the 21st century.

The message resounds loud and clear, most recently from Pisa’s Andreas Schleicher, who probably alarmed the education select committee by commenting that arts subjects will be more important than Stem in the future. Meanwhile, arguments rage between adherents of a “knowledge-rich” curriculum and those who want it to be “skills-based”.

These are false dichotomies, about as useful as those medieval theological arguments about how many cherubim could fit on the head of a pin. But Schleicher is right to throw down the challenge. Any new curriculum must equip the next generation of adults for the creative, flexible, entrepreneurial and open-ended challenges that their multiple careers will throw at them.

That’s easy to say: but what would my ideal curriculum look like? I can’t answer that in a single Tes blog, but I know I must start by laying out what a curriculum both must and shouldn’t seek to achieve. Here goes.

The must-nots

1. The curriculum mustn’t be determined by the exams children take at 11,16,18 or any other age, and certainly not by government measures or benchmarks based on them. The EBacc skews curriculum/subject choices by creating a subject hierarchy, as do universities identifying “facilitating subjects” at A level.
   
   I have similar reservations about Baccalaureate systems (even, dare I whisper it, the IB), which inevitably enforce particular choice-ranges through their chosen model for achieving breadth.

2. If young people need to demonstrate competence in basic skills – and I think they do – a suitable test must be devised. The curriculum mustn’t allow GCSE to act as a measure of functional competence in, for instance, literacy and numeracy: it’s an academic exam, not such a measure.
   
   The 30 per cent of children who don’t achieve a Grade 5 may nonetheless have a basic level of competence, but gain little from GCSE apart from humiliation and misery.

3. The curriculum mustn’t be a drawing-board to indulge the whims or ambitions of adults, not even of politicians. Nor a list of everything that we think it’s good for kids to learn. Old hands will remember how, in the late 1980s, the newly-devised National Curriculum couldn’t fit into the week: every subject pressure-group had jumped onto the bandwagon and demanded its slice of the cake.
   
   Any realistic curriculum plan must value vocational/technical learning equally to academic and acknowledge that not everything can be squeezed in, that choices must be made – by children where possible, not adults.

The musts

1. The curriculum must create the best opportunities and lead to best outcomes for young people.

2. The curriculum must have space for discrete subjects as we currently know them, but there needs to be coherence. Students who want to must be able to go into great depth (A level and beyond) in their chosen subjects: otherwise schools won’t produce doctors, musicians, artists, scientists, architects and all the other specialists society needs. Secondary education still needs expert teachers with great subject knowledge able to stretch and inspire pupils.

3. Last, and crucially, the curriculum must make and protect space for all the other stuff, the overview and the glue that hold all that classroom learning together and help make sense of it. PSHE is essential, with all that it embraces, and all other forms of guidance and support including careers advice and experience.
   
   But equally vital are those other activities, often (misleadingly) called co-curricular (and, worse, extra-curricular): singing, playing or acting in a group, team sports or competitions, outdoor education, voluntary service. These and a host of other activities are the elements that build character, resilience, altruism, appreciation of community and social responsibility.

I guess now I’ll have to write further pieces to unpack some of this and answer the howls of rage that come in response.

But we have to start somewhere: and not, above all, with every interest-group bending the ears of ministers and officials and fighting for market – sorry, curriculum – share.

Dr Bernard Trafford is a writer, educationalist, musician and former independent school headteacher. He tweets at @bernardtrafford