In 2006, the 84-year-old Kurt Vonnegut wrote a letter to a class of schoolchildren who had asked him to visit. He was too ill to travel, but offered them instead the following lesson for life: “Practise any art, music, singing, dancing, acting, drawing, painting, sculpting, poetry, fiction, essays, reportage, not to get money and fame, but to experience becoming, to find out what’s inside you, to make your soul grow.”

Beautiful advice, certainly; there’s no question that access to art and literature, and the opportunity to explore creative expression, can broaden young people’s outlook, boost their confidence and encourage empathy and curiosity about the wider world. Middle-class parents have always known this; it’s why their children are signed up for MiniMozart groups and pre-school Mandarin classes before they can walk. Being “cultured” opens doors even if you don’t pursue a career in the arts; private schools know this and usually offer a rich and varied extracurricular programme of artistic activities. But Vonnegut’s exhortation is not so easy to follow for young people who have little opportunity or guidance when it comes to the arts.

Schools used to provide those opportunities, often backed up by community youth projects. But funding for the latter has shrivelled and state-school teachers find their time and resources stretched thinner than ever; many schools are simply unable to provide the kind of music tuition, theatre or gallery trips and after-school clubs that my state comprehensive offered in the 1980s. But the greatest worry is that creative writing, art, drama and music, once an integral part of the curriculum, are losing their status in favour of moreobviously “commercially useful” subjects.

Last week, a survey based on statistics published by Ofqual revealed a fivefold decline in the number of pupils taking GCSEs in arts subjects over the past year, and entrants for A-levels in arts subjects dropped by 4,300 this summer. In a straitened economy – and we hardly know yet how much worse that will become – arts are increasingly seen as “soft subjects”, despite assurance from the education secretary, Nicky Morgan, who said last year that she “firmly rejected” the suggestion that the government considered the arts “less important”. This was the same Nicky Morgan who warned pupils in 2014 that choosing arts over STEM (science, technology, engineering and maths) subjects could “hold them back for the rest of their lives”. The statistics suggest that this doom-laden prophecy has been taken seriously by the current cohort.

My 14-year-old son chose his GCSE options this year; the fact that the school sent an accompanying letter assuring parents that arts subjects would not be considered inferior to maths and sciences by the top universities was telling in itself. But the structure of the timetable, which allowed only one choice between art, music and drama, and none of those if the child also wanted to study a second language, hardly seemed to bear that out.

It’s widely feared among arts professionals and teachers that the implementation of the EBacc in September, with its narrow range of core subjects and absence of the expressive arts, is only likely to exacerbate the drop-off. It’s an oddly short-sighted view that has been the subject of reports and campaigns by the Creative Industries Federation, which emphasises the contribution of the creative sector to the economy and works to promote the potential employment benefits to students choosing arts subjects. Encouraging young people to study creative arts to find out what’s inside them is all well and good, but it’s also useful to provide figures reassuring them that there are jobs at the end of it. On 4 July, parliament will debate the inclusion of expressive arts subjects in the Ebacc as the result of a petition started by Essex drama teacher Richard Wilson, which has now gathered more than 100,000 signatories. In the meantime, in the absence of a coherent government commitment to arts provision in schools, charities and individuals are having to fill the gap.

Theatre director Fiona Laird set up the National Youth Arts Trust in 2013 to provide bursaries for talented children who found themselves unable to develop their skills for want of the most basic provision – the cost of a musical instrument or the train fare to attend a drama school audition in London. It now supports more than 1,000 young people through different projects; patrons include Ewan McGregor, Adrian Lester, Gary Kemp and Christopher Eccleston. “So many of my friends who are successful actors say they wouldn’t have been able to get started in their careers now,” Laird says. ‘The performing arts are becoming luxuries for rich kids and that’s wrong, because talent doesn’t go with money.”

Writers William Fiennes and Katie Waldegrave started the charity First Story to allow professional novelists to tutor creative writing in challenging schools; comedian Josie Long founded Arts Emergency, which provides mentors and encourages the study of arts subjects at college and university among young people who might otherwise regard them as an unaffordable luxury. Last week the current children’s laureate, Chris Riddell, and a group of his predecessors convened to discuss ways to promote creative learning in schools.’

But the obvious problem with charities is that by definition they can’t be everywhere and such an approach is no substitute for a nationwide educational commitment to the arts that reflects the value of the creative sector to the economy and to personal wellbeing.

A generation of young people who wanted overwhelmingly to be European citizens and already feel betrayed will grow up to shape the next few decades. Carving out a space for them to express themselves creatively at school and college, and not necessarily in ways that have to be assessed and tabled through exams, will be crucial to developing imagination, curiosity and empathy, qualities so painfully lacking in the recent political debate and which might do much to shape a more tolerant future society.

The government should consider not only the inclusion of the expressive arts in the EBacc curriculum, but also investment in teachers who can provide art, drama and music outside the timetable, for the less tangible – but no less valuable – purpose of expanding minds and, yes, growing souls.