If you really want to understand the subtly shifting place of education in the nation’s psyche, you could start by watching Channel 4’s 24 Hours in A&E. Dedicated professionals deploying skill, tenacity and tenderness towards citizens of every age, faith, shape and class – it’s a story we seem never to tire of. It’s proof that the NHS, despite all its problems, is still the nearest thing this country has to a religion.

And yet, this passion for our often struggling health system poses a conundrum that has long fascinated me. Both the NHS and free secondary education arose from the collective optimism of the years after the second world war, pillars of the newly founded welfare state. Yet while the NHS, set up in 1948, generated instant and enduring affection, the 1944 Education Act, which established the right to free secondary education for all children up to 15 (now 18), is far less lauded, and our school system has more often spawned a nagging sense of dissatisfaction and division.

In one sense, the reason is glaringly obvious. Although there had been discussion before the war about setting up a “multilateral” (that is, comprehensive) system of secondary education, parliament opted for a three-tiered arrangement, which became two as technical schools never took off. So was the grammar-secondary modern divide born, channelling most poor children into poorly funded, less well-regarded schools.

Imagine if NHS hospitals and surgeries had been set up with two entrances: one for the affluent, one for the poor. Or if politicians had spent the succeeding half a century dismissing big general hospitals as blinkered examples of an outdated “one injury fits all” ideology.

Of course, we need and expect different things from our health and education systems. While our encounters with the NHS are largely episodic, times of emergency and vulnerability, the school we attend is often taken as the crucible of our identity. The wealthy still use A&E, but many wouldn’t dream of going anywhere near a local school, a reminder that perhaps the biggest mistake of that heroic postwar period was the failure to integrate the public schools into the new universal state system, so missing a unique opportunity to bridge what remains one of the most damaging divides in society.

For all that, there have been periods when one could glimpse a shift in public attitudes towards state education, an idealism to match the NHS. One significant moment came in the 60s with the move towards comprehensive education, but although the 11-plus was phased out in most parts of the country, more subtle forms of selection have continued to stoke division.

Gove-ism represented another key shift, as an influential section of the Conservative party finally ditched its party’s traditional support for grammars and embraced an almost militant evangelism about high-quality non-selective education, even if some academies and free schools are driven to use their so-called freedoms to keep out lower-performing children.

Television programmes such as Educating Essex and Educating Yorkshire have generated public affection and respect for the ordinary heroism of staff and pupils in our state schools, while lazy anti-comprehensive prejudice has been undercut by a new generation in public life educated in non-selective schools, including the education secretary, Justine Greening.

We should be deeply worried, then, by reports that Theresa May intends to lift the 18-year ban on creating new grammar schools. The rhetoric is predictably obfuscating, with a lot of guff about making secondary moderns better or letting selective schools operate as “specialists” in a more diverse, choice-driven schools market.

The grammar lobby is clearly displaying post-Brexit braggadocio in trying to drag us back to a discredited past. Such a move would not only be educationally, socially and morally wrong headed, it would be a near criminal waste of a powerful and unprecedented moment in the story of our state education system: the existence of a strong evidence-based consensus across a wide spectrum of political opinion that we could, and should, create a quality system along genuinely multilateral lines.

Build on, and invest in, that vision and it’s possible public loyalty to state education will continue to grow. Return to crass historical divisions, and the dissatisfaction and disunion will surely last for another half century – or longer.

This article was published in the Guardian on August 9th 2016