David Thomas has worked as a Head of Maths at a central London comprehensive school and as an adviser at the Department for Education.

Character is the new fad in education. We all want to develop good character in our children, but the policy that achieves this has proven elusive.

Proponents of every conceivable activity have queued up to explain how their pet project develops character (and so should get to dip their hands in the pot of government gold).

But while many of these are perfectly good things, building our children’s character requires much more fundamental change.

So instead of looking for new projects to fund, let us ask a different question: why is there a deficit that needs to be made up in the first place?

The deficit exists because the core activity of schools – lessons – can become too easy and too self-consciously fun to need any character at all.

Take resilience as an example. A child learns resilience by practising. They try tasks that are difficult, fail at them, and keep trying again. Eventually they learn that you do not need to give up when you face difficulty, but can be successful if you invest enough effort.

But do our lessons give children the opportunity to learn this? When I went through teacher training I was taught that my job was to make everything easy for all children; and that lessons should always be so engaging that they would join in effortlessly.

If a lesson required resilience then you were a bad teacher for not setting the bar so low everyone was guaranteed to succeed, or for not making the lesson so devoid of content everyone was guaranteed to find it fun.

As teachers are being told this by trainers, authors and consultants across the country, they are delivering courses designed to minimise the need for resilience. Subjects are coursework-heavy and exam-light. The knowledge required is both narrow and shallow. Exam boards compete on how easy they could make their courses.

Most teachers rage against this machine. When nobody’s looking they teach difficult lessons and expect hard work from their students. They refuse to demean the subjects they love by infantilising them and replacing content with distraction.

They know that engaging students means engaging them in the academia, not distracting them from it. But they face a horrible moral dilemma.

If they don’t jump through the hoops, and present their students with fill-in-the-blank coursework templates, then they disadvantage their students. They don’t want to, but nor do they want the children they care about to be at an unfair disadvantage.

This is not teachers’ faults; this is the system’s fault.

In the last five years we’ve started to improve this system, but reform at such a deep level isn’t easy. When the government launched new, harder English and Maths GCSEs, the exam boards managed to find the shortest eligible book for their English specifications, and it took almost a year of work by Ofqual to bring the Maths courses up to the required standard.

There has been reform in Ofsted too, but whilst the wording of the framework has changed many teachers report that the behaviour and judgement of inspectors has not.

Against this backdrop, Nicky Morgan has taken up an interest in character. She knows that traits like resilience are essential for success in both child and adult life and so wants our schools to find ways to foster and develop it.

So there have been rounds of funding for initiatives that develop character – rugby coaches, first aid, and military ethos camps have all won big payouts. These are all undoubtedly good things that will have a positive impact on the children lucky enough to be involved. But they are not the government’s most powerful lever.

Much of the focus on extra-curricular activities has come from a desire to emulate the success of private schools. It is assumed that the main difference between the private and state sectors is the former’s focus on extra-curricular activities, and so these must be the cause of better character.

The problem with this reasoning is that extra-curricular activities are not the main difference. The main difference is that the private sector, free to choose more rigorous exams and free from the imposition of local authority inspectors and consultants, has never needed to strip the character out of its teaching.

The biggest thing this government can do to teach character is to make sure children are being taught hard things.

Children spend five days a week in lessons, but only five days in their life at an extra-curricular camp. Increasing the challenge of each class gives children constant opportunities to build their character, without needing to wait for their turn on the outdoor activity course.

So the government needs to keep the focus on rigour in education. See through the exam reform that will make courses demand some resilience. Keep schools free from bureaucracies that pressure them to dumb down their teaching. Support teachers to teach hard lessons where students struggle before attaining truly valuable understanding of a subject.

A school system that values character is one that doesn’t shy away from expecting it.