More than a year before Clarke the younger’s outrage, the chair of the Headmasters’ Conference, Edward Gould, warned that “civility is in retreat, vulgarity advances” (TES, January 18, 2002). But he was referring to the “real world” outside school - in contrast to public behaviour, most of our schools are oases of good manners and decorum.

At least children in my school are relatively well behaved. As in many others, our assemblies are well disciplined, even though, as head, I am the only adult in the hall. Teachers used to ride shotgun to make sure the children behaved and paid attention to my pearls of wisdom, but they get little enough non-contact time, and it was obvious that the children had a sense of self-discipline we could trust. Some of them may be present in body but absent in spirit, but at least they are polite enough to stay quiet.

Peer pressure is at least partly responsible for pupils conforming to expected standards of behaviour. The embarrassment of 339 pairs of eyes on you is a mighty persuader. The wrath of the head may also play a small part.

But the equivalent pressures to behave in society at large are diminishing, as I experienced at the weekend, when I went to the theatre. On the way to the station I was cut up by white van man in his weekend 4x4. I reflected that this happens frequently because, sitting in our tin boxes, we are isolated from our fellow human beings. But scarcely had I reached the station platform when a repeat performance came, courtesy of a tattooed, bald-headed pedestrian who seemed to resent my occupying space he deemed his.

And once on the crowded train, I was forced to share a carriage with two female equivalents of Harry Enfield’s Slobs. We stuttered through the weekend engineering works to the accompaniment of swearing, farting and shouting by these two young women as they used their mobiles to arrange an all-night birthday party in a mixed sauna and massage parlour. Strangely, in between text messaging, they sang pop songs in duet, fortissimo.

As a young lad, I often wondered why the council painted “No spitting, swearing or singing” at the front of double-decker buses. I could not believe anyone would be brave enough to risk the opprobrium of fellow passengers by doing the first two, and had never met anyone cheerful enough to want to do the last. In any case, the bus conductor ruled with a rod of iron, chastising the most minor of offenders. In the train, we needed such a disciplinarian, but no authority figure emerged. And no amount of silent disapproval from the rest of us had any effect. So, with true British phlegm, we suffered their discourteous behaviour in silence.

At the theatre I mingled with a self-selected group of cultured people.

Fondly imagining I was entering more civilised circles, I was disappointed when, during the interval, the well-dressed woman next to me took off her shoes and stretched her toes over to her partner, who massaged them thoroughly. An energetic head massage followed, which, from the muffled noises that followed, carried on for some time after the actors had come back on stage.

Back in school on Monday, I appreciated even more keenly how well mannered and self-disciplined most of our pupils are.

The Education Secretary’s son was quite properly suspended, with the full support of his parents. Pity we don’t have such effective means of social discipline in the real world.

Bob Aston is headteacher of a junior school in Medway